Atlantica Sustainable Infrastructure (AY) 20-F 7 Mar 18 2017 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2017shares
Document and Entity Information [Abstract]
Entity Registrant Name	Atlantica Yield plc
Entity Central Index Key	1,601,072
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	100,217,260
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2017

Consolidated statements of fina

Consolidated statements of financial position - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Non-current assets
Contracted concessional assets	$ 9,084,270	$ 8,924,272
Investments carried under the equity method	55,784	55,009
Other receivables accounts	37,012	65,951
Derivative assets	8,230	3,822
Financial investments	45,242	69,773
Deferred tax assets	165,136	202,891
Total non-current assets	9,350,432	9,251,945
Current assets
Inventories	17,933	15,384
Trade receivables	186,728	151,199
Credits and other receivables	57,721	56,422
Clients and other receivables	244,449	207,621
Financial investments	210,138	228,038
Cash and cash equivalents	669,387	594,811
Total current assets	1,141,907	1,045,854
Total assets	10,492,339	10,297,799
Equity attributable to the Company
Share capital	10,022	10,022
Parent company reserves	2,163,229	2,268,457
Other reserves	80,968	52,797
Accumulated currency translation differences	(18,147)	(133,150)
Retained earnings	(477,214)	(365,410)
Non-controlling interest	136,595	126,395
Total equity	1,895,453	1,959,111
Non-current liabilities
Long-term corporate debt	574,176	376,340
Borrowings	4,413,172	3,824,871
Notes and bonds	815,745	804,313
Long-term project debt	5,228,917	4,629,184
Grants and other liabilities	1,636,060	1,612,045
Related parties	141,031	101,750
Derivative liabilities	329,731	349,266
Deferred tax liabilities	186,583	95,037
Total non-current liabilities	8,096,498	7,163,622
Current liabilities
Short-term corporate debt	68,907	291,861
Borrowings	215,117	674,058
Notes and bonds	31,174	27,225
Short-term project debt	246,291	701,283
Trade payables and other current liabilities	155,144	160,505
Income and other tax payables	30,046	21,417
Total current liabilities	500,388	1,175,066
Total equity and liabilities	$ 10,492,339	$ 10,297,799

Consolidated income statements

Consolidated income statements - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated income statements [Abstract]
Revenue	$ 1,008,381	$ 971,797	$ 790,881
Other operating income	80,844	65,538	68,857
Raw materials and consumables used	(16,983)	(26,919)	(23,243)
Employee benefit expenses	(18,854)	(14,736)	(5,848)
Depreciation, amortization, and impairment charges	(310,960)	(332,925)	(261,301)
Other operating expenses	(284,461)	(260,318)	(224,828)
Operating profit	457,967	402,437	344,518
Financial income	1,007	3,298	3,464
Financial expense	(463,717)	(408,007)	(333,921)
Net exchange differences	(4,092)	(9,546)	3,852
Other financial income/(expense), net	18,434	8,505	(200,153)
Financial expense, net	(448,368)	(405,750)	(526,758)
Share of profit/(loss) of associates carried under the equity method	5,351	6,646	7,844
Profit/(loss) before income tax	14,950	3,333	(174,396)
Income tax	(119,837)	(1,666)	(23,790)
Profit/(loss) for the year	(104,887)	1,667	(198,186)
Loss/(profit) attributable to non-controlling interests	(6,917)	(6,522)	(10,819)
Profit/(loss) for the year attributable to the Company	$ (111,804)	$ (4,855)	$ (209,005)
Weighted average number of ordinary shares outstanding (in shares)	100,217	100,217	92,795
Basic earnings per share (in dollars per share)	$ (1.12)	$ (0.05)	$ (2.25)

Consolidated statements of comp

Consolidated statements of comprehensive income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated statements of comprehensive income [Abstract]
Profit/(loss) for the year	$ (104,887)	$ 1,667	$ (198,186)
Items that may be subject to transfer to income statement
Change in fair value of cash flow hedges	(28,535)	(37,480)	56
Currency translation differences	121,924	(22,150)	(91,405)
Tax effect	4,426	12,555	1,950
Net income/(expenses) recognized directly in equity	97,815	(47,075)	(89,399)
Cash flow hedges	70,953	72,774	55,841
Tax effect	(17,738)	(18,194)	(13,960)
Transfers to income statement	53,215	54,580	41,881
Other comprehensive income/(loss)	151,030	7,505	(47,518)
Total comprehensive income/(loss) for the year	46,143	9,172	(245,704)
Total comprehensive (income)/loss attributable to non-controlling interest	(14,773)	(9,629)	(3,550)
Total comprehensive income/(loss) attributable to the Company	$ 31,370	$ (457)	$ (249,254)

Consolidated statements of chan

Consolidated statements of changes in equity - USD ($) $ in Thousands		Total	Total Equity Attributable to Company [Member]	Share Capital [Member]	Parent Company Reserves [Member]	Other Reserves [Member]	Retained Earnings [Member]	Accumulated Currency Translation Differences [Member]	Non-controlling Interest [Member]
Balance, beginning of period at Dec. 31, 2014		$ 1,839,631	$ 1,751,602	$ 8,000	$ 1,790,135	$ (15,539)	$ (2,031)	$ (28,963)	$ 88,029
Profit/(loss) for the year after taxes		(198,186)	(209,005)	0	0	0	(209,005)	0	10,819
Change in fair value of cash flow hedges		55,897	51,215	0	0	51,215	0	0	4,682
Currency translation differences		(91,405)	(80,619)	0	0	0	0	(80,619)	(10,786)
Tax effect		(12,010)	(10,845)	0	0	(10,845)	0	0	(1,165)
Other comprehensive income/(loss)		(47,518)	(40,249)	0	0	40,370	0	(80,619)	(7,269)
Total comprehensive income/(loss) for the year		(245,704)	(249,254)	0	0	40,370	(209,005)	(80,619)	3,550
Asset acquisition under the Rofo/Seville PV		(87,861)	(145,488)	0	0	0	(145,488)	0	57,627
Dividend distribution		(146,302)	(137,995)	0	(137,995)	0	0	0	(8,307)
Capital increase		663,737	663,737	2,022	661,715	0	0	0	0
Balance, end of period at Dec. 31, 2015		2,023,501	1,882,602	10,022	2,313,855	24,831	(356,524)	(109,582)	140,899
Profit/(loss) for the year after taxes		1,667	(4,855)	0	0	0	(4,855)	0	6,522
Change in fair value of cash flow hedges		35,294	32,944	0	0	32,944	0	0	2,350
Currency translation differences		(22,150)	(23,568)	0	0	0	0	(23,568)	1,418
Tax effect		(5,639)	(4,978)	0	0	(4,978)	0	0	(661)
Other comprehensive income/(loss)		7,505	4,398	0	0	27,966	0	(23,568)	3,107
Total comprehensive income/(loss) for the year		9,172	(457)	0	0	27,966	(4,855)	(23,568)	9,629
Acquisition of non-controlling interest in Solacor 1&2	[1]	(19,925)	(4,031)	0	0	0	(4,031)	0	(15,894)
Asset acquisition under the Rofo/Seville PV	[1]	713	0	0		0	0	0	713
Dividend distribution		(54,350)	(45,398)	0	(45,398)	0	0	0	(8,952)
Balance, end of period at Dec. 31, 2016		1,959,111	1,832,716	10,022	2,268,457	52,797	(365,410)	(133,150)	126,395
Profit/(loss) for the year after taxes		(104,887)	(111,804)	0	0	0	(111,804)	0	6,917
Change in fair value of cash flow hedges		42,418	41,242	0	0	41,242	0	0	1,176
Currency translation differences		121,924	115,003	0	0	0	0	115,003	6,921
Tax effect		(13,312)	(13,071)	0	0	(13,071)	0	0	(241)
Other comprehensive income/(loss)		151,030	143,174	0	0	28,171	0	115,003	7,856
Total comprehensive income/(loss) for the year		46,143	31,370	0	0	28,171	(111,804)	115,003	14,773
Dividend distribution		(109,801)	(105,228)	0	(105,228)	0	0	0	(4,573)
Balance, end of period at Dec. 31, 2017		$ 1,895,453	$ 1,758,858	$ 10,022	$ 2,163,229	$ 80,968	$ (477,214)	$ (18,147)	$ 136,595
[1]	See Note 5 for further details.

Consolidated cash flow statemen

Consolidated cash flow statements - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated cash flow statements [Abstract]
I. Profit/(loss) for the year		$ (104,887)	$ 1,667	$ (198,186)
Non-monetary adjustments
Depreciation, amortization and impairment charges		310,960	332,925	261,301
Financial (income)/expenses		443,517	397,966	553,300
Fair value (gains)/losses on derivative financial instruments		759	(1,761)	(4,292)
Shares of (profits)/losses from associates		(5,351)	(6,646)	(7,844)
Income tax		119,837	1,666	23,790
Changes in consolidation and other non-monetary items		(20,882)	(59,375)	(91,410)
II. Profit for the year adjusted by non monetary items		743,953	666,442	536,659
Variations in working capital
Inventories		(2,548)	(729)	(1,198)
Clients and other receivables		(23,799)	(15,001)	14,845
Trade payables and other current liabilities		22,474	11,422	9,994
Financial investments and other current assets/liabilities		(4,924)	6,341	49,420
III. Variations in working capital		(8,797)	2,033	73,061
Income tax received/(paid)		(4,779)	(1,953)	522
Interest received		4,139	3,342	1,600
Interest paid		(348,893)	(335,446)	(312,357)
A. Net cash provided by/(used in) operating activities		385,623	334,418	299,485
Investments in entities under the equity method		3,003	4,984	4,417
Investments in contracted concessional assets	[1]	30,058	(5,952)	(106,007)
Other non-current assets/liabilities		8,183	(3,637)	5,714
(Acquisitions)/Sales of subsidiaries and other financial instruments		30,124	(21,754)	(833,974)
B. Net cash used in investing activities		71,368	(26,359)	(929,850)
Proceeds from Project & Corporate debt		296,398	11,113	459,366
Repayment of Project & Corporate debt		(613,242)	(182,636)	(175,389)
Dividends paid to Company's shareholders		(99,483)	(35,509)	(137,166)
Proceeds from capital increase		0	0	664,120
Purchase of shares to non-controlling interests		0	(19,071)	0
C. Net cash provided by/(used in) financing activities		(416,327)	(226,103)	810,931
Net increase/(decrease) in cash and cash equivalents		40,664	81,956	180,566
Cash, cash equivalents and bank overdrafts at beginning of the year		594,811	514,712	354,154
Translation differences cash or cash equivalent		33,912	(1,857)	(20,008)
Cash and cash equivalents at the end of the year		$ 669,387	$ 594,811	$ 514,712
[1]	Includes proceeds for $42.5 million and investments for $12.4 million (see Note 6).

Consolidated cash flow stateme7

Consolidated cash flow statements (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Consolidated cash flow statements [Abstract]
Proceeds from investments in contracted concessional assets	$ 42.5
Purchase of investments in contracted concessional assets	$ 12.4

Nature of the business

Nature of the business	12 Months Ended
	Dec. 31, 2017
Nature of the business [Abstract]
Nature of the business	Note 1.- Nature of the business Atlantica Yield plc (“Atlantica Yield” or the “Company”) was incorporated in England and Wales as a private limited company on December 17, 2013 under the name Abengoa Yield Limited. On March 19, 2014, the Company was re-registered as a public limited company, under the name Abengoa Yield plc. On May 13, 2016, the change of the Company´s registered name to Atlantica Yield plc was filed with the Registrar of Companies in the United Kingdom. Atlantica Yield is a total return company that owns, manages and acquires renewable energy, efficient natural gas (previously denominated “conventional power”) , electric transmission lines and water assets focused on North America (the United States and Mexico), South America (Peru, Chile and Uruguay) and EMEA (Spain, Algeria and South Africa). The Company’s largest shareholder is Abengoa S.A. (“Abengoa”), which, based on the most recent public information, currently owns a 41.47 % stake in Atlantica Yield. Abengoa does not consolidate the Company in its consolidated financial statements. On June 18, 2014, Atlantica Yield closed its initial public offering issuing 24,850,000 ordinary shares. The shares were offered at a price of $29 per share, resulting in gross proceeds to the Company of $720,650 thousand. The underwriters further purchased 3,727,500 additional shares from the selling shareholder, a subsidiary wholly owned by Abengoa, at the public offering price less fees and commissions to cover over-allotments (“greenshoe”) driving the total proceeds of the offering to $828,748 thousand. Prior to the consummation of the initial public offering, Abengoa contributed, through a series of transactions, which we refer to collectively as the “Asset Transfer,” ten concessional assets, certain holding companies and a preferred equity investment in Abengoa Concessoes Brasil Holding (“ACBH”), which is a subsidiary of Abengoa engaged in the development, construction, investment and management of contracted concessions in Brazil, comprised mostly of transmission lines. As consideration for the Asset Transfer, Abengoa received a 64.28% interest in Atlantica Yield and $655.3 million in cash, corresponding to the net proceeds of the initial public offering less $30 million retained by Atlantica Yield for liquidity purposes. Atlantica Yield’s shares began trading on the NASDAQ Global Select Market under the symbol “ABY” on June 12, 2014. The symbol changed to “AY” on November 11, 2017. During 2016, the Company closed the acquisition of a 13% stake in Solacor 1/2 from the JGC Corporation (“JGC”), which reduced the JGC´s ownership in Solacor 1/2 to 13%, and of an 80% stake in Fotovoltaica Solar Sevilla, S.A. (“Seville PV”) from Abengoa, a 1 MW solar photovoltaic plant in Spain. On February 28, 2017, the Company closed the acquisition of a 12.5% interest in a 114-mile transmission line in the U.S. from Abengoa. The asset will receive a Federal Energy Regulatory Commission (“FERC”) regulated rate of return, and is currently under development, with Commercial Operation Date (“COD”) expected in 2020. On July 20, 2017, the Company reached an agreement to acquire, subject to approvals from the relevant authorities in Peru, a 4 MW hydroelectric power plant in Peru for approximately $9 million. The following table provides an overview of the concessional assets the Company owned as of December 31, 2017 (excluding the 12.5% interest in the transmission line in the U.S. acquired in February 2017): Assets Type Ownership Location Currency (8) Capacity (Gross) Counterparty Credit Ratings (9) COD* Contract Years Left (12) Solana Renewable (Solar) 100% Class B (1) Arizona (USA) USD 280 MW A-/A3/A- 4Q 2013 26 Mojave Renewable (Solar) 100% California (USA) USD 280 MW A-/A3/A- 4Q 2014 22 Solaben 2 & 3 Renewable (Solar) 70% (2) Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2012 & 2Q 2012 20&19 Solacor 1 & 2 Renewable (Solar) 87% (3) Spain Euro 2x50 MW BBB+/Baa2/A- 1Q 2012 & 1Q 2012 19 PS10/PS20 Renewable (Solar) 100% Spain Euro 31 MW BBB+/Baa2/A- 1Q 2007 & 2Q 2009 14&16 Helioenergy 1 & 2 Renewable (Solar) 100% Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2011& 4Q 2011 19 Helios 1 & 2 Renewable (Solar) 100% Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2012& 3Q 2012 20 Solnova 1, 3 & 4 Renewable (Solar) 100% Spain Euro 3x50 MW BBB+/Baa2/A- 2Q 2010 & 2Q 2010& 3Q 2010 17&17&18 Solaben 1 & 6 Renewable (Solar) 100% Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2013 21 Kaxu Renewable (Solar) 51% (4) South Africa Rand 100 MW BB/Baa3/BB+ (10) 1Q 2015 17 Palmatir Renewable (Wind) 100% Uruguay USD 50 MW BBB/Baa2/BBB- (11) 2Q 2014 16 Cadonal Renewable (Wind) 100% Uruguay USD 50 MW BBB/Baa2/BBB- (11) 4Q 2014 17 ACT Efficient natural gas 100% Mexico USD 300 MW BBB+/A3/ BBB+ 2Q 2013 15 ATN Transmission line 100% Peru USD 362 miles BBB+/A3/BBB+ 1Q 2011 23 ATS Transmission line 100% Peru USD 569 miles BBB+/A3/BBB+ 1Q 2014 26 ATN 2 Transmission line 100% Peru USD 81 miles Not rated 2Q 2015 15 Quadra 1 Transmission line 100% Chile USD 49 miles Not rated 2Q 2014 17 Quadra 2 Transmission line 100% Chile USD 32 miles Not rated 1Q 2014 17 Palmucho Transmission line 100% Chile USD 6 miles BBB+/Baa2/BBB+ 4Q 2007 20 Skikda Water 34.2% (5) Algeria USD 3.5 M ft3/day Not rated 1Q 2009 16 Honaine Water 25.5% (6) Algeria USD 7 M ft3/ day Not rated 3Q 2012 20 Seville PV Renewable (Solar) 80% (7) Spain Euro 1 MW BBB+/Baa2/A- 3Q 2006 18 (1) On September 30, 2013, Liberty Interactive Corporation invested $300,000 thousand in Class A membership interests in exchange for a share of the dividends and taxable loss generated by Solana. As a result of the agreement, Liberty Interactive Corporation will receive between 54.06% and 61.20% of both dividends and taxable loss generated, additional amounts until the date Liberty reaches a certain rate of return or the “Flip Date”, and 22.60% of both dividends and taxable loss generated thereafter. (2) Itochu Corporation, a Japanese trading company, holds 30% of the shares in each of Solaben 2 and Solaben 3. (3) JGC, a Japanese engineering company, holds 13% of the shares in each of Solacor 1 and Solacor 2. (4) Kaxu is owned by the Company (51%), Industrial Development Corporation of South Africa (29%) and Kaxu Community Trust (20%). (5) Algerian Energy Company, SPA owns 49% of Skikda and Valoriza Agua, S.L. owns the remaining 16.83%. (6) Algerian Energy Company, SPA owns 49% of Honaine and Valoriza Agua, S.L. owns the remaining 25.5%. (7) Instituto para la Diversificación y Ahorro de la Energía (“Idae”), a Spanish state owned company, holds 20% of the shares in Seville PV. (8) Certain contracts denominated in U.S. dollars are payable in local currency. (9) Reflects the counterparty’s credit ratings issued by Standard & Poor’s Ratings Services, or S&P, Moody’s Investors Service Inc., or Moody’s, and Fitch Ratings Ltd, or Fitch. (10) Refers to the credit rating of the Republic of South Africa. The offtaker is Eskom, which is a state-owned utility company in South Africa. (11) Refers to the credit rating of Uruguay, as UTE (Administración Nacional de Usinas y Transmisoras Eléctricas) is unrated. (12) As of December 31, 2017. * Commercial Operation Date (“COD”). On November 27, 2015 Abengoa, reported that, it filed a communication pursuant to article 5 bis of the Spanish Insolvency Law 22/2003 with the Mercantile Court of Seville nº 2. On November 8, 2016, the Judge of the Mercantile Court of Seville declared judicial approval of Abengoa´s restructuring agreement, extending the terms of the agreement to those creditors who had not approved the restructuring agreement. On February 3, 2017, Abengoa announced it obtained approval from creditors representing 94% of its financial debt after the supplemental accession period. On March 31, 2017 Abengoa announced the completion of the restructuring. As a result, Atlantica Yield received Abengoa debt and equity instruments in exchange of the guarantee previously provided by Abengoa regarding the preferred equity investment in ACBH. In addition, the Company invested in Abengoa´s issuance of asset-backed notes (the “New Money 1 Tradable Notes”) in order to convert the junior status of the Abengoa debt received into senior debt (see Note 8). The financing arrangement of Kaxu contained as of December 31, 2016 cross-default provisions related to Abengoa, such that debt defaults by Abengoa, subject to certain threshold amounts and/or a restructuring process, could trigger defaults under such project financing arrangement. In March 2017, the Company signed a waiver which gives clearance to cross-default that might have arisen from Abengoa insolvency and restructuring up to that date, but does not extend to potential future cross-default events. The financing arrangement of Cadonal also contained cross-default provisions with Abengoa and a waiver was obtained in 2016, subject to certain conditions. These conditions were met in October 2017. In addition, as of December 31, 2016 the financing arrangements of Kaxu, ACT, Solana and Mojave contained a change of ownership clause that would be triggered if Abengoa ceased to own at least 35% of Atlantica Yield's shares (30% in the case of Solana and Mojave). Based on the most recent public information, Abengoa currently owns 41.47% of Atlantica Yield shares and 41.44% of the outstanding shares have been pledged as guarantee of the New Money 1 Tradable Notes and loans. On November 1, 2017 Abengoa announced it has reached an agreement with Algonquin Power & Utilities Corp. (“Algonquin”) to sell a 25% stake in Atlantica Yield subject to conditions precedent. Additionally, Abengoa has communicated that it intends to sell its remaining 16.5% stake over the upcoming months in a private transaction subject to approval by the U.S. Department of Energy (the “DOE”). Algonquin has an option to purchase this remaining stake until March 2018. If Abengoa ceases to comply with its obligation to maintain its 30% ownership of Atlantica Yield 's shares, such reduced ownership would put the Company in breach of covenants under the applicable project financing arrangements. In the case of Solana and Mojave, a forbearance agreement signed with the DOE in 2016 with respect to these assets allows reductions of Abengoa’s ownership of the shares of the Company if it results from (i) a sale or other disposition at any time pursuant and in connection with a subsequent insolvency proceeding by Abengoa, or (ii) capital increases by the Company. In other events of reduction of ownership by Abengoa below the minimum ownership threshold such as sales of stake in Atlantica Yield by Abengoa, the available DOE remedies will not include debt acceleration, but DOE remedies available could include limitations on distributions to the Company from Solana and Mojave. In addition, the minimum ownership threshold for Abengoa’s ownership of the shares of the Company has been reduced from 35% to 30%. In November 2017, in the context of the agreement reached between Abengoa and Algonquin for the acquisition by Algonquin of 25% of the shares of the Company and based on the obligations of Abengoa under the EPC contract the Company signed a consent with the DOE which reduces this minimum ownership required by Abengoa in Atlantica Yield to 16%, subject to certain conditions precedent most of which are beyond the control of Atlantica Yield (see Note 10). In the case of Kaxu, in March 2017 the Company signed a waiver, which allows reduction of ownership by Abengoa below the 35% threshold if it is done in the context of the restructuring plan. Additionally, the Company obtained in October 2017 the waiver for ACT Additionally, on February 10, 2017, the Company issued senior secured notes (the “Note Issuance Facility”) with a group of funds managed by Westbourne Capital as purchasers of the notes issued thereunder for a total amount of €275 million (approximately $330 million as of December 31, 2017). The proceeds of the Note Issuance Facility were used to fully repay Tranche B under the Company´s Credit Facility, which was then canceled (see Note 14). These consolidated financial statements were approved by the Board of Directors of the Company on February 27, 2018.

Significant accounting policies

Significant accounting policies	12 Months Ended
	Dec. 31, 2017
Significant accounting policies [Abstract]
Significant accounting policies	Note 2.- Significant accounting policies 2.1 Basis of preparation These consolidated financial statements are presented in accordance with the International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”). The Company entered into an agreement with Abengoa on June 13, 2014 (the “ROFO Agreement”), as amended and restated on December 9, 2014, that provides the Company with a right of first offer on any proposed sale, transfer or other disposition of any of Abengoa’s contracted renewable energy, efficient natural gas, electric transmission or water assets in operation and located in the United States, Canada, Mexico, Chile, Peru, Uruguay, Brazil, Colombia and the European Union, as well as four assets in selected countries in Africa, the Middle East and Asia. The Company elected to account for the assets acquisitions under the ROFO Agreement using the Predecessor values as long as Abengoa had control over the Company, given that these were transactions between entities under common control. Any difference between the consideration given and the aggregate book value of the assets and liabilities of the acquired entities as of the date of the transaction has been reflected as an adjustment to equity. Abengoa has no control over the Company since December 31, 2015. Therefore, any acquisition from Abengoa is accounted for in the consolidated accounts of Atlantica Yield since December 31, 2015, in accordance with IFRS 3, Business Combination. The consolidated financial statements are presented in U.S. dollars, which is the Company’s functional and presentation currency. Amounts included in these consolidated financial statements are all expressed in thousands of U.S. dollars, unless otherwise indicated. Application of new accounting standards a) Standards, interpretations and amendments effective from January 1, 2017 under IFRS-IASB, applied by the Company in the preparation of these consolidated financial statements: • IAS • IAS 12 (Amendment) ‘Recognition for Deferred Tax for Unrealized Losses’. Clarification of recognition of deferred tax assets for unrealized losses. • Annual Improvements to IFRSs 2014-2016 cycles. Amendments to IFRS 12. The applications of these amendments have not had any material impact on these consolidated financial statements except for the reconciliation of liabilities arising from financial activities that has been included in Note 14 and 15. b) Standards, interpretations and amendments published by the IASB that will be effective for periods beginning on or after January 1, 2018: • IFRS 9 ‘Financial Instruments’. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 9 (Amendments to IFRS 9): Prepayment Features with Negative Compensation. This Standard is applicable for annual periods beginning on or after January 1, 2019 under IFRS-IASB, earlier application is permitted. • IFRS 15 ‘Revenues from Contracts with Customers’. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 15 (Clarifications) ‘Revenues from Contracts with Customers’. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 16 ‘Leases’. This Standard is applicable for annual periods beginning on or after January 1, 2019 under IFRS-IASB, earlier application is permitted. • IFRS 17 ‘Insurance Contracts’. This Standard is applicable for annual periods beginning on or after January 1, 2021 under IFRS-IASB, earlier application is permitted. • IFRS 2 (Amendment) ‘Classification and Measurement of Share-based Payment Transactions’. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 4 (Amendment). Applying IFRS 9 ‘Financial Instruments’ with IFRS 4 ‘Insurance Contracts’. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IAS 40 (Amendment). Transfers of Investment Property. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IAS 19 (Amendment). Amendments to IAS 19: Plan Amendment, Curtailment or Settlement. This amendment is mandatory for annual periods beginning on or after January 1, 2019 under IFRS-IASB, earlier application is permitted. • IAS 28 (Amendment). Long-term Interests in Associates and Joint Ventures. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • Annual Improvements to IFRSs 2014-2016 cycles. Other minor amendments and modifications different from the aforementioned on IFRS 12. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB. • Annual Improvements to IFRSs 2015-2017 cycles. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB. • IFRIC 22 Foreign Currency Transactions and Advance Consideration. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB. • IFRIC 23 Uncertainty over Income Tax Treatments. This Standard is applicable for annual periods beginning on or after January 1, 2019 under IFRS-IASB. • IFRS 10 and IAS 28. Parent disposes of (or contributes) its controlling interest in a subsidiary to an existing associate or joint venture. Effective date beginning on or after a date to be determined by the IASB. The application of these accounting standards is not expected to have a material impact on the consolidated financial statements of the Company. The analysis performed by the Company, relating to the impact of the new relevant accounting standards is as follows: IFRS 15 ‘Revenues from contracts with Customers’ In May 2014, the IASB (International Accounting Standards Board) published IFRS 15 “Recognition of Revenue from Contracts with Customers”. This Standard brings together all the applicable requirements and replaces the current standards for recognizing revenue: IAS 11 Construction Contracts, IAS 18 Revenue, IFRIC 13 Customer Loyalty Program, IFRIC 15 Agreements for the Construction of Real Estate, IFRIC 18 Transfers of Assets from Customers and SIC-31 Revenue—Barter Transactions Involving Advertising Services. The new requirements may lead to changes in the current revenue profile, since the Standard's main principle is that the Company must recognize its revenue in accordance with the transfer of goods or services to the customers in an amount which reflects the consideration that the Company expects to receive in exchange for these goods or services. The model laid out by the Standard is structured in five steps: · Step 1: Identifying the contract with the customer. · Step 2: Identifying the performance obligations. · Step 3: Determining the transaction price. · Step 4: Assigning the transaction price in the performance obligations identified in the contract. · Step 5: Recognition of revenue when (or as) the Company performs the performance obligations. Contracted concessional assets and price purchase agreements (PPAs) include fixed assets financed through project debt, related to service concession arrangements recorded in accordance with International Financial Reporting Interpretations Committee 12 (“IFRIC 12”), except for Palmucho, which is recorded in accordance with IAS 17 and PS10, PS20 and Seville PV, which are recorded as tangible assets in accordance with IAS 16. The infrastructures accounted for by the Company as concessions are related to the activities concerning electric transmission lines, solar electricity generation plants, cogeneration plants, wind farms and water plants. Currently, assets recorded in accordance with IFRIC 12 are classified as intangible assets or as financial assets, depending on the nature of the payment entitlements established in the contracts. According to IFRS 15, the Company should assess the goods and services promised in the contracts with the customers and shall identify as a performance obligation each promise to transfer to the customer a good or service (or a bundle of goods or services). In the case of contracts related to financial assets, the Company has identified two performance obligations (construction and operation of the asset). The contracts state that each service (construction and operation) has its own transaction price. For this reason, both performance obligations are separately identifiable in the context of the contract. The Company must allocate the total consideration to be received by the contract to each performance obligation. As mentioned above, the different services performed have been identified as two different performance obligations (construction and operation). Each performance obligation has its own transaction price stated in the contract. Such transaction prices are agreed in the contract by the parties in an orderly transaction, with no interrelation between both transaction prices and therefore correspond to the fair value of the goods and services provided in each case. As a result, for IFRS 15 purposes, the total transaction price will be allocated to each performance obligation in accordance with the two transaction prices stated within the contract, as they represent the respective fair values of the identified performance obligations. For the assets classified as intangible assets, the Company has identified the same performance obligations, (construction and operation), but in this case the consideration received by the Company for the construction services is a license. The grantor makes a non-cash payment for the construction services by giving the operator an intangible asset. When allocating fair value for IFRS 15 purposes, the Company will recognize as revenue for the first performance obligation the fair value of the construction services, and the amount corresponding to the sales of energy as the fair value of second performance obligation (operation). Additionally, in both cases, the services are satisfied over time. Therefore, the Company satisfies the performance obligations and recognizes revenue over time. The same conclusion applies to concessional assets that are classified as tangible assets or leases. IFRS 15 also incorporates specific criteria to determine which costs relating to a contract should be capitalized by distinguishing between incremental costs of obtaining a contract and costs associated with fulfilling a contract. No significant costs of obtaining a contract or compliance (other than those that are already capitalized) have been identified. As the current practice for revenue recognition is consistent with the analysis above under IFRS 15, the Company considers that the adoption of this standard will not have impact in the consolidated financial statements of the Company. Also, the Company has the intention to adopt IFRS 15 applying the full retrospective method to each prior reporting period presented, but without changes in the comparative reporting periods as the adoption of the standard has no effect in the financial statements. IFRS 9 ‘Financial Instruments’ IFRS 9 Financial Instruments issued on 24 July 2014 is the IASB's replacement of IAS 39 Financial Instruments: Recognition and Measurement. The standard addresses the classification, measurement and derecognition of financial assets and financial liabilities, introduces new rules for hedge accounting and a new impairment model for financial assets. The Company will be adopting the standard as of January 1, 2018, including the new requirements for hedge accounting (which application is voluntary for 2018). The Company will be adopting retrospectively without re-expressing comparative periods. The analysis performed by the Company is as follows: · Classification and measurement of financial instruments: a) Financial assets IFRS 9 classifies all financial assets that are currently in the scope of IAS 39 into two categories: amortized cost and fair value. Where assets are measured at fair value, gains and losses are either recognized entirely in profit or loss (fair value through profit or loss, “FVTPL”), or recognized in other comprehensive income (fair value through other comprehensive income, “FVTOCI”). The new guidance has no significant impact on the classification and measurement of the financial assets of the Company as the vast majority of financial assets (except for derivatives) are currently measured at amortized cost, and meet the conditions for classification at amortized cost under IFRS9. The Company has the intention of maintaining this classification. b) Financial liabilities: IFRS 9 does not change the basic accounting model for financial liabilities under IAS 39. Two measurement categories continue to exist: FVTPL and amortized cost. Financial liabilities held for trading are measured at FVTPL, and all other financial liabilities are measured at amortized cost unless the fair value option is applied. As a result, the Company concluded that there will be no significant impact on the consolidated financial statements. · The new impairment model requires the recognition of impairment provisions based on expected credit losses (“ECL”) rather than only incurred credit losses as is the case under IAS 39. The Company reviewed its portfolio of financial assets subject to the new model of impairment under the new methodology (using credit default swaps, rating from credit agencies and other external inputs in order to estimate the probability of default), and concluded that initial impact on the consolidated financial statements is not significant. · The accounting for certain modifications and exchanges of financial liabilities measured at amortized cost (e.g. bank loans and issued bonds) will change on the transition from IAS 39 to IFRS 9. This change arises from a clarification by the IASB in the Basis for Conclusions of IFRS 9. Under IFRS 9 it is now clear that there can be an effect in the income statement for modification and exchanges of financial liabilities that are considered “non-substantial” (when the net present value of the cash flows, including any fees paid net of any fees received, is lower than 10% different from the net present value of the remaining cash flows of the liability prior to the modification, both discounted at the original effective interest rate). The Company reviewed retrospectively these transactions and concluded that the impact is not significant. · IFRS 9 also introduces changes in hedge accounting. The hedge accounting requirements in IFRS 9 are optional and tend to facilitate the use of hedge accounting by preparers of financial statements. As a result, the Company reviewed its portfolio of derivatives and concluded that there will not be significant impact on its consolidated financial statements as a result of applying IFRS 9. · The new standard will require some new disclosures, in particular regarding hedge accounting, credit risk and ECLs that will be presented in future periods. IFRS 16 ‘Leases’ The IASB issued a new lease accounting standard, IFRS 16, in January 2016, which will require the recognition of lease contracts on the consolidated statement of financial position. IFRS 16 eliminates the classification of leases as either operating leases or finance leases for a lessee. Instead all leases are treated in a similar way to finance leases applying IAS 17. Leases are ‘capitalized’ by recognizing the present value of the lease payments and showing them either as lease assets (right-of-use of assets) or together with property, plant and equipment. If lease payments are made over time, a company also recognizes a financial liability representing its obligation to make future lease payments. In the income statement, IFRS 16 replaces the straight-line operating lease expense for those leases applying IAS 17, with a depreciation charge for the lease asset (included within operating expenses) and an interest expense on the lease liability (included within finance expenses). The Company performed its assessment of the impact on its consolidated financial statements. The most significant impact identified is that the Company will recognize new assets and liabilities for its existing operating leases of land rights, buildings, offices and equipment. The standard is effective for annual periods beginning on or after January 1, 2019, with earlier application permitted for entities that apply IFRS 15 at or before the date of initial application of IFRS 16. The Company decided to early adopt the standard as of January 1, 2018. An entity shall apply this standard using one of the following two methods: full retrospectively approach or a modified retrospective approach. The Company has chosen the latter and will account for assets as an amount equal to liability at the date of initial application. The Company estimates the impact on the consolidated statement of financial position as of January 1, 2018, is not significant (less than 1% of total assets). 2.2. Principles to include and record companies in the consolidated financial statements Companies included in these consolidated financial statements are accounted for as subsidiaries as long as Atlantica Yield has had control over them and are accounted for as investments under the equity method as long as Atlantica Yield has had significant influence over them, in the periods presented. a) Controlled entities Control is achieved when the Company: · Has power over the investee; · Is exposed, or has rights, to variable returns from its involvement with the investee; and · Has the ability to use its power to affect its returns. The Company reassesses whether or not it controls an investee when facts and circumstances indicate that there are changes to one or more of the three elements of control listed above. The Company uses the acquisition method to account for business combinations of companies controlled by a third party. According to this method, identifiable assets acquired and liabilities and contingent liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. Any contingent consideration is recognized at fair value at the acquisition date and subsequent changes in its fair value are recognized in accordance with IAS 39 either in profit or loss or as a change to other comprehensive income. Acquisition related costs are expensed as incurred. The Company recognizes any non-controlling interest in the acquiree either at fair value or at the non-controlling interest’s proportionate share of the acquirer’s net assets on an acquisition by acquisition basis. Acquisitions of businesses from Abengoa were until December 31, 2015, not considered business combinations, as Atlantica Yield was a subsidiary controlled by Abengoa. The assets acquired constituted an acquisition under common control by Abengoa and accordingly, were recorded using Abengoa’s historical basis in the assets and liabilities of the Predecessor. Abengoa has no control over the Company since December 31, 2015. Therefore, any purchase from Abengoa is accounted for in the consolidated accounts of Atlantica Yield since December 31, 2015, in accordance with IFRS 3, Business Combination. All assets and liabilities between entities of the group, equity, income, expenses, and cash flows relating to transactions between entities of the group are eliminated in full. b) Investments accounted for under the equity method An associate is an entity over which the Company has significant influence. Significant influence is the power to participate in the financial and operating policy decisions of the investee but is not control or joint control over those policies. The results and assets and liabilities of associates are incorporated in these financial statements using the equity method of accounting. Under the equity method, an investment in an associate is initially recognized in the statement of financial position at cost and adjusted thereafter to recognize the Company share of the profit or loss and other comprehensive income of the associate. Controlled entities and associates included in these financial statements as of December 31, 2017 and 2016 are set out in appendices. 2.3. Contracted concessional assets and price purchase agreements Contracted concessional assets and price purchase agreements (PPAs) include fixed assets financed through project debt, related to service concession arrangements recorded in accordance with IFRIC 12, except for Palmucho, which is recorded in accordance with IAS 17 and PS10, PS20 and Seville PV, which are recorded as tangible assets in accordance with IAS 16. The infrastructures accounted for by the Company as concessions are related to the activities concerning electric transmission lines, solar electricity generation plants, cogeneration plants, wind farms and water plants. The useful life of these assets is approximately the same as the length of the concession arrangement. The infrastructure used in a concession can be classified as an intangible asset or a financial asset, depending on the nature of the payment entitlements established in the agreement. The application of IFRIC 12 requires extensive judgment in relation with, among other factors, (i) the identification of certain infrastructures and contractual agreements in the scope of IFRIC 12, (ii) the understanding of the nature of the payments in order to determine the classification of the infrastructure as a financial asset or as an intangible asset and (iii) the timing and recognition of the revenue from construction and concessionary activity. Under the terms of contractual arrangements within the scope of this interpretation, the operator shall recognize and measure revenue in accordance with IAS 11 and 18 for the services it performs. If the operator performs more than one service (i.e. construction or upgrade services and operation services) under a single contract or arrangement, consideration received or receivable shall be allocated by reference to the relative fair values of the services delivered, when the amounts are separately identifiable. a) Intangible asset The Company recognizes an intangible asset to the extent that it receives a right to charge final customers for the use of the infrastructure. This intangible asset is subject to the provisions of IAS 38 and is amortized linearly, taking into account the estimated period of commercial operation of the infrastructure which coincides with the concession period. Once the infrastructure is in operation, the treatment of income and expenses is as follows: · Revenues from the updated annual revenue for the contracted concession, as well as operations and maintenance services are recognized in each period according to IAS 18 “Revenue”. · Operating and maintenance costs and general overheads and administrative costs are recorded in accordance with the nature of the cost incurred (amount due) in each period. · Financing costs are expensed as incurred. b) Financial asset The Company recognizes a financial asset when demand risk is assumed by the grantor, to the extent that the concession holder has an unconditional right to receive payments for the asset. This asset is recognized at the fair value of the construction services provided, considering upgrade services in accordance with IAS 11, if any. The financial asset is subsequently recorded at amortized cost calculated according to the effective interest method. Revenue from operations and maintenance services is recognized in each period according to IAS 18 “Revenue”. The remuneration of managing and operating the asset resulting from the valuation at amortized cost is also recorded in revenue. Financing costs are expensed as incurred. c) Property, plant and equipment Property, plant and equipment includes property, plant and equipment of companies or project companies. Property, plant and equipment is measured at historical cost, including all expenses directly attributable to the acquisition, less depreciation and impairment losses, with the exception of land, which is presented net of any impairment losses. Once the infrastructure is in operation, the treatment of income and expenses is the same as the one described above for intangible asset. 2.4. Borrowing costs Interest costs incurred in the construction of any qualifying asset are capitalized over the period required to complete and prepare the asset for its intended use. A qualifying asset is an asset that necessarily takes a substantial period of time to get ready for its internal use or sale, which is considered to be more than one year. Remaining borrowing costs are expensed in the period in which they are incurred. 2.5 Asset impairment Atlantica Yield reviews its contracted concessional assets to identify any indicators of impairment at least annually. The recoverable amount of an asset is the higher of its fair value less costs to sell and its value in use, defined as the present value of the estimated future cash flows to be generated by the asset. In the event that the asset does not generate cash flows independently of other assets, the Company calculates the recoverable amount of the Cash Generating Unit (‘CGU’) to which the asset belongs. When the carrying amount of the CGU to which these assets belong is higher than its recoverable amount, the assets are impaired. Assumptions used to calculate value in use include a discount rate, growth rate and projections considering real data based in the contracts terms and projected changes in both selling prices and costs. The discount rate is estimated by Management, to reflect both changes in the value of money over time and the risks associated with the specific CGU. For contracted concessional assets, with a defined useful life and with a specific financial structure, cash flow projections until the end of the project are considered and no terminal value is assumed. Contracted concessional assets have a contractual structure that permits the Company to estimate quite accurately the costs of the project (both in the construction and in the operations periods) and revenue during the life of the project. Projections take into account real data based on the contract terms and fundamental assumptions based on specific reports prepared by experts, assumptions on demand and assumptions on production. Additionally, assumptions on macro-economic conditions are taken into account, such as inflation rates, future interest rates, etc. and sensitivity analyses are performed over all major assumptions which can have a significant impact in the value of the asset. Cash flow projections of CGUs are calculated in the functional currency of those CGUs and are discounted using rates that take into consideration the risk corresponding to each specific country and currency. Taking into account that in most CGUs the specific financial structure is linked to the financial structure of the projects that are part of those CGUs, the discount rate used to calculate the present value of cash-flow projections is based on the weighted average cost of capital (WACC) for the type of asset, adjusted, if necessary, in accordance with the business of the specific activity and with the risk associated with the country where the project is performed. In any case, sensitivity analyses are performed, especially in relation with the discount rate used and fair value changes in the main business variables, in order to ensure that possible changes in the estimates of these items do not impact the possible recovery of recognized assets. Accordingly, the following table provides a summary of the discount rates used (WACC) and growth rates to calculate the recoverable amount for CGUs with the operating segment to which it pertains: Operating segment Discount rate Growth rate EMEA 4% - 6 % 0 % North America 4% - 6 % 0 % South America 5% - 7 % 0 % In the event that the recoverable amount of an asset is lower than its carrying amount, an impairment charge for the difference would be recorded in the income statement under the item “Depreciation, amortization and impairment charges”. Pursuant to IAS 36, an impairment loss is recognized if the carrying amount of these assets exceeds the present value of future cash flows discounted at the initial effective interest rate. 2.6 Loans and accounts receivable Loans and accounts receivable are non-derivative financial assets with fixed or determinable payments, not listed on an active market. In accordance with IFRIC 12, certain assets under concessions qualify as financial assets and are recorded as is described in Note 2.3. Pursuant to IAS 36, an impairment loss is recognized if the carrying amount of these assets exceeds the present value of future cash flows discounted at the initial effective interest rate. Loans and accounts receivable are initially recognized at fair value plus transaction costs and are subsequently measured at amortized cost in accordance with the effective interest rate method. Interest calculated using the effective interest rate method is recognized under other financial income within financial income. 2.7. Derivative financial instruments and hedging activities Derivatives are recorded at fair value. The Company applies hedge accounting to all hedging derivatives that qualify to be accounted for as hedges under IFRS-IASB. When hedge accounting is applied, hedging strategy and risk management objectives are documented at inception, as well as the relationship between hedging instruments and hedged items. Effectiveness of the hedging relationship needs to be assessed on an ongoing basis. Effectiveness tests are performed prospectively and retrospectively at inception and at each reporting date, following the dollar offset method or the regression method, depending on the type of derivatives and the type of tests performed. Atlantica Yield applies cash flow hedging. Under this method, the effective portion of changes in fair value of derivatives designated as cash flow hedges are recorded temporarily in equity and are subsequently reclassified from equity to profit or loss in the same period or periods during which the hedged item affects profit or loss. Any ineffective portion of the hedged transaction is recorded in the consolidated income statement as it occurs. When interest rate options are designated as hedging instruments, the intrinsic value and time value of the financial hedge instrument are separated. Changes in intrinsic value which are highly effective are recorded in equity and subsequently reclassified from equity to profit or loss in the same period or periods during which the hedged item affects profit or loss. Changes in time value are recorded as financial income or expense, together with any ineffectiveness. When the hedging instrument matures or is sold, or when it no longer meets the requirements to apply hedge accounting, accumulated gains and losses recorded in equity remain as such until the forecast transaction is ultimately recognized in the income statement. However, if it becomes unlikely that the forecast transaction will actually take place, the accumulated gains and losses in equity are recognized immediately in the income statement. 2.8. Fair value estimates Financial instruments measured at fair value are presented in accordance with the following level classification based on the nature of the inputs used for the calculation of fair value: · Level 1: Inputs are quoted prices in active markets for identical assets or liabilities. · Level 2: Fair value is measured based on inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. as prices) or indirectly (i.e. derived from prices). · Level 3: Fair value is measured based on unobservable inputs for the asset or liability. In the event that prices cannot be observed, the management shall make its best estimate of the price that the market would otherwise establish based on proprietary internal models which, in the majority of cases, use data based on observable market parameters as significant inputs (Level 2) but occasionally use market data that is not observed as significant inputs (Level 3). Different techniques can be used to make this estimate, including extrapolation of observable market data. The best indication of the initial fair value

Financial risk management

Financial risk management	12 Months Ended
	Dec. 31, 2017
Financial risk management [Abstract]
Financial risk management	Note 3.- Financial risk management Atlantica Yield’s activities are exposed to various financial risks: market risk (including currency risk and interest rate risk), credit risk and liquidity risk. Risk is managed by the Company’s Risk Finance and Compliance Departments, which are responsible for identifying and evaluating financial risks quantifying them by project, region and company, in accordance with mandatory internal management rules. Written internal policies exist for global risk management, as well as for specific areas of risk. In addition, there are official written management regulations regarding key controls and control procedures for each company and the implementation of these controls is monitored through internal audit procedures. a) Market risk The Company is exposed to market risk, such as movement in foreign exchange rates and interest rates. All of these market risks arise in the normal course of business and the Company does not carry out speculative operations. For the purpose of managing these risks, the Company uses a series of interest rate swaps and options, and currency options. None of the derivative contracts signed has an unlimited loss exposure. - Interest rate risk Interest rate risk arises when the Company’s activities are exposed to changes in interest rates, which arises from financial liabilities at variable interest rates. The main interest rate exposure for the Company relates to the variable interest rate with reference to the Libor and Euribor. To minimize the interest rate risk, the Company primarily uses interest rate swaps and interest rate options (caps), which, in exchange for a fee, offer protection against an increase in interest rates. The Company does not use derivatives for speculative purposes. As a result, the notional amounts hedged, strikes contracted and maturities, depending on the characteristics of the debt on which the interest rate risk is being hedged, are very diverse, including the following: o Project debt in Euros: the Company hedges between 87% and 100% of the notional amount, maturities until 2030 and average guaranteed interest rates of between 3.20% and 4.87%. o Project debt in U.S. dollars: the Company hedges between 70% and 100% of the notional amount, including maturities until 2032 and average guaranteed interest rates of between 2.32% and 5.27%. In connection with the interest rate derivative positions of the Company, the most significant impacts on these consolidated financial statements are derived from the changes in EURIBOR or LIBOR, which represent the reference interest rate for the majority of the debt of the Company. In the event that Euribor and Libor had risen by 25 basis points as of December 31, 2017, with the rest of the variables remaining constant, the effect in the consolidated income statement would have been a loss of $228 thousand (a loss of $2,563 thousand in 2016 and a loss of $1,795 thousand in 2015) and an increase in hedging reserves of $37,767 thousand ($37,290 thousand in 2016 and $41,702 thousand in 2015). The increase in hedging reserves would be mainly due to an increase in the fair value of interest rate swaps designated as hedges. A breakdown of the interest rates derivatives as of December 31, 2017 and 2016, is provided in Note 9. - Currency risk The main cash flows in the entities included in these consolidated financial statements are cash collections arising from long-term contracts with clients and debt payments arising from project finance repayment. Given that financing of the projects is always closed in the same currency in which the contract with client is signed, a natural hedge exists for the main operations of the Company. In addition, the Company policy is to contract currency options with leading financial institutions, which guarantee a minimum Euro-U.S. dollar exchange rate on the net distributions expected from Spanish solar assets. The net Euro exposure is 100% covered for the coming 12 months and 75% for the following 12 months on a rolling basis. b) Credit risk The Company considers that it has a limited credit risk with clients as revenues derive from power purchase agreements with electric utilities and state-owned entities. The Company has investment grade offtakers in all the assets except for Quadra 1&2, ATN2, Skikda and Honaine, which represent a low percentage of the cash available for distribution on a run-rate basis. In the case of Kaxu, the offtaker has a counter-guarantee from the Republic of South Africa. c) Liquidity risk Atlantica Yield’s liquidity and financing policy is intended to ensure that the Company maintains sufficient funds to meet our financial obligations as they fall due. Project finance borrowing permits the Company to finance the project through project debt and thereby insulate the rest of its assets from such credit exposure. The Company incurs in project-finance debt on a project-by-project basis. The repayment profile of each project is established on the basis of the projected cash flow generation of the business. This ensures that sufficient financing is available to meet deadlines and maturities, which mitigates the liquidity risk significantly.

Financial information by segmen

Financial information by segment	12 Months Ended
	Dec. 31, 2017
Financial information by segment [Abstract]
Financial information by segment	Note 4.- Financial information by segment Atlantica Yield’s segment structure reflects how management currently makes financial decisions and allocates resources. Its operating and reportable segments are based on the following geographies where the contracted concessional assets are located: · North America · South America · EMEA Based on the type of business, as of December 31, 2017 the Company had the following business sectors: Renewable energy: Efficient natural gas: Electric transmission lines Water: 3 Atlantica Yield’s Chief Operating Decision Maker (CODM) assesses the performance and assignment of resources according to the identified operating segments. The CODM considers the revenues as a measure of the business activity and the Further Adjusted EBITDA as a measure of the performance of each segment. Further Adjusted EBITDA is calculated as profit/(loss) for the period attributable to the parent company, after adding back loss/(profit) attributable to non-controlling interests from continued operations, income tax, share of profit/(loss) of associates carried under the equity method, finance expense net, depreciation, amortization and impairment charges of entities included in these consolidated financial statements, and dividends received from the preferred equity investment in ACBH. Further adjusted EBITDA for 2016 and 2017 includes compensation received from Abengoa in lieu of ACBH dividends. In order to assess performance of the business, the CODM receives reports of each reportable segment using revenues and Further Adjusted EBITDA. Net interest expense evolution is assessed on a consolidated basis. Financial expense and amortization are not taken into consideration by the CODM for the allocation of resources. In the years ended December 31, 2017 and December 31, 2016, Atlantica Yield had three customers with revenues representing more than 10% of the total revenues, i.e., two in the renewable energy and one in the efficient natural gas business sectors. a) The following tables show Revenues and Further Adjusted EBITDA by operating segments and business sectors for the years 2017, 2016 and 2015: Revenue Further Adjusted EBITDA For the year ended December 31, For the year ended December 31, Geography 2017 2016 2015 2017 2016 2015 North America $ 332,705 $ 337,061 $ 328,139 $ 282,328 $ 284,691 $ 279,559 South America 120,797 118,764 112,480 108,766 124,599 110,905 EMEA 554,879 515,972 350,262 388,216 354,020 233,754 Total $ 1,008,381 $ 971,797 $ 790,881 $ 779,310 $ 763,310 $ 624,218 Revenue Further Adjusted EBITDA For the year ended December 31, For the year ended December 31, Business sectors 2017 2016 2015 2017 2016 2015 Renewable energy $ 767,226 $ 724,325 $ 543,012 $ 569,193 $ 538,427 $ 413,933 Efficient natural gas 119,784 128,046 138,717 106,140 106,492 107,671 Electric transmission lines 95,096 95,137 86,393 87,695 104,795 89,047 Water 26,275 24,288 22,759 16,282 13,596 13,567 Total $ 1,008,381 $ 971,797 $ 790,881 $ 779,310 $ 763,310 $ 624,218 The reconciliation of segment Further Adjusted EBITDA with the profit/(loss) attributable to the parent company is as follows: For the year ended December 31, 2017 2016 2015 Loss attributable to the Company $ (111,804 ) $ (4,855 ) $ (209,005 ) Profit attributable to non-controlling interests 6,917 6,522 10,819 Income tax 119,837 1,666 23,790 Share of profits/(losses) of associates (5,351 ) (6,646 ) (7,844 ) Dividend from exchangeable preferred equity investment in ACBH (Note 21) 10,383 27,948 18,400 Financial expense, net 448,368 405,750 526,758 Depreciation, amortization, and impairment charges 310,960 332,925 261,301 Total segment Further Adjusted EBITDA $ 779,310 $ 763,310 $ 624,219 b) The assets and liabilities by operating segments (and business sector) at the end of 2017 and 2016 are as follows: Assets and liabilities by geography as of December 31, 2017: North America South America EMEA Balance as of December 31, 2017 Assets allocated Contracted concessional assets 3,770,169 1,100,778 4,213,323 9,084,270 Investments carried under the equity method - - 55,784 55,784 Current financial investments 116,451 59,831 31,263 207,545 Cash and cash equivalents (project companies) 149,236 42,548 329,078 520,862 Subtotal allocated 4,035,856 1,203,157 4,629,448 9,868,461 Unallocated assets Other non-current assets 210,378 Other current assets (including cash and cash equivalents at holding company level) 413,500 Subtotal unallocated 623,878 Total assets 10,492,339 North America South America EMEA Balance as of December 31, 2017 Liabilities allocated Long-term and short-term project debt 1,821,102 876,063 2,778,043 5,475,208 Grants and other liabilities 1,593,048 810 42,202 1,636,060 Subtotal allocated 3,414,150 876,873 2,820,245 7,111,268 Unallocated liabilities Long-term and short-term corporate debt 643,083 Other non-current liabilities 657,345 Other current liabilities 185,190 Subtotal unallocated 1,485,618 Total liabilities 8,596,886 Equity unallocated 1,895,453 Total liabilities and equity unallocated 3,381,071 Total liabilities and equity 10,492,339 Assets and liabilities by geography as of December 31, 2016: North America South America EMEA Balance as of December 31, 2016 Assets allocated Contracted concessional assets 3,920,106 1,144,712 3,859,454 8,924,272 Investments carried under the equity method - - 55,009 55,009 Current financial investments 136,665 62,215 29,158 228,038 Cash and cash equivalents (project companies) 185,970 40,015 246,671 472,656 Subtotal allocated 4,242,741 1,246,942 4,190,291 9,679,975 Unallocated assets Other non-current assets 272,664 Other current assets (including cash and cash equivalents at holding company level) 345,160 Subtotal unallocated 617,824 Total assets 10,297,799 North America South America EMEA Balance as of December 31, 2016 Liabilities allocated Long-term and short-term project debt 1,870,861 895,316 2,564,290 5,330,467 Grants and other liabilities 1,575,303 1,512 35,230 1,612,045 Subtotal allocated 3,446,164 896,828 2,599,520 6,942,512 Unallocated liabilities Long-term and short-term corporate debt 668,201 Other non-current liabilities 546,053 Other current liabilities 181,922 Subtotal unallocated 1,396,176 Total liabilities 8,338,688 Equity unallocated 1,959,111 Total liabilities and equity unallocated 3,355,287 Total liabilities and equity 10,297,799 Assets and liabilities by business sectors as of December 31, 2017: Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2017 Assets allocated Contracted concessional assets 7,436,362 660,387 897,269 90,252 9,084,270 Investments carried under the equity method 12,419 - - 43,365 55,784 Current financial investments 17,249 116,430 59,289 14,577 207,545 Cash and cash equivalents (project companies) 452,792 39,064 15,325 13,681 520,862 Subtotal allocated 7,918,822 815,881 971,883 161,875 9,868,461 Unallocated assets Other non-current assets 210,378 Other current assets (including cash and cash equivalents at holding company level) 413,500 Subtotal unallocated 623,878 Total assets 10,492,339 Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2017 Liabilities allocated Long-term and short-term project debt 4,162,596 579,173 698,346 35,093 5,475,208 Grants and other liabilities 1,635,508 552 - - 1,636,060 Subtotal allocated 5,798,104 579,725 698,346 35,093 7,111,268 Unallocated liabilities Long-term and short-term corporate debt 643,083 Other non-current liabilities 657,345 Other current liabilities 185,190 Subtotal unallocated 1,485,618 Total liabilities 8,596,886 Equity unallocated 1,895,453 Total liabilities and equity unallocated 3,381,071 Total liabilities and equity 10,492,339 Assets and liabilities by business sectors as of December 31, 2016: Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2016 Assets allocated Contracted concessional assets 7,255,308 646,927 929,005 93,032 8,924,272 Investments carried under the equity method 12,953 - - 42,056 55,009 Current financial investments 13,661 136,644 62,215 15,518 228,038 Cash and cash equivalents (project companies) 420,215 30,295 11,357 10,789 472,656 Subtotal allocated 7,702,137 813,866 1,002,577 161,395 9,679,975 Unallocated assets Other non-current assets 272,664 Other current assets (including cash and cash equivalents at holding company level) 345,160 Subtotal unallocated 617,824 Total assets 10,297,799 Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2016 Liabilities allocated Long-term and short-term project debt 3,979,096 598,256 711,517 41,598 5,330,467 Grants and other liabilities 1,611,067 239 739 - 1,612,045 Subtotal allocated 5,590,163 598,495 712,256 41,598 6,942,512 Unallocated liabilities Long-term and short-term corporate debt 668,201 Other non-current liabilities 546,053 Other current liabilities 181,922 Subtotal unallocated 1,396,176 Total liabilities 8,338,688 Equity unallocated 1,959,111 Total liabilities and equity unallocated 3,355,287 Total liabilities and equity 10,297,799 c) The amount of depreciation, amortization and impairment charges recognized for the years ended December 31, 2017, 2016 and 2015 are as follows: For the year ended December 31, Depreciation, amortization and impairment by geography 2017 2016 2015 North America (123,726 ) (129,478 ) (129,091 ) South America (40,880 ) (62,387 ) (41,274 ) EMEA (146,354 ) (141,060 ) (90,936 ) Total (310,960 ) (332,925 ) (261,301 ) For the year ended December 31, Depreciation, amortization and impairment by business sectors 2017 2016 2015 Renewable energy (282,376 ) (304,235 ) (232,699 ) Electric transmission lines (28,584 ) (28,690 ) (28,602 ) Total (310,960 ) (332,925 ) (261,301 )

Changes in the scope of the con

Changes in the scope of the consolidated financial statements	12 Months Ended
	Dec. 31, 2017
Changes in the scope of the consolidated financial statements [Abstract]
Changes in the scope of the consolidated financial statements	Note 5.- Changes in the scope of the consolidated financial statements For the year ended December 31, 2017 There is no change in the scope of the consolidated financial statement in the year 2017. For the year ended December 31, 2016 On January 7, 2016, the Company closed the acquisition of a 13% stake in Solacor 1/2 from JGC, which reduced JGC´s ownership in Solacor 1/2 to 13%. The total purchase price for these assets amounted to $19,923 thousand. The difference between the amount of Non-Controlling interest representing the 13% interest held by JGC accounted for in the consolidated accounts at the purchase date, and the purchase price has been recorded in equity in these consolidated financial statements, pursuant to IFRS 10, Consolidated Financial Statements . On August 3, 2016, the Company completed the acquisition of an 80% stake in Seville PV. Total purchase price paid for this asset amounted to $3,214 thousand. The purchase has been accounted for in the consolidated accounts of Atlantica Yield, in accordance with IFRS 3, Business Combinations.

Contracted concessional assets

Contracted concessional assets	12 Months Ended
	Dec. 31, 2017
Contracted concessional assets [Abstract]
Contracted concessional assets	Note 6.- Contracted concessional assets Contracted concessional assets include fixed assets financed through project debt, related to service concession arrangements recorded in accordance with IFRIC 12, except for Palmucho, which is recorded in accordance with IAS 17, and PS10, PS20 and Seville PV which are recorded as property plant and equipment in accordance with IAS 16. Concessional assets recorded in accordance with IFRIC 12 are either intangible of financial assets. As of December 31, 2017, contracted concessional financial assets amount to $936,004 thousand ($928,720 thousand as of December 31, 2016). For further details on the application of IFRIC 12 to projects, see Appendix III. a) The following table shows the movements of contracted concessional assets included in the heading “Contracted Concessional assets” for 2017: Cost Total as of January 1, 2017 10,067,596 Additions 15,426 Subtractions (42,500 ) Translation differences 593,247 Total as of December 31, 2017 10,633,769 Accumulated amortization Total as of January 1, 2017 (1,143,324 ) Additions (309,846 ) Translation differences (96,329 ) Total accum. amort. as of December 31, 2017 (1,549,499 ) Net balance at December 31, 2017 9,084,270 During 2017 contracted concessional assets increased primarily due to the effect of appreciation of the Euro against the U.S. dollar for the year ended December 31, 2017 compared to the year ended December 31, 2016, this effect has been partially compensated by the amortization charge for the year. The decrease relates to the indemnity received from Abengoa by Solana in December 2017 further to Abengoa´s obligation as EPC Contractor (see Note 10). No losses from impairment of contracted concessional assets were recorded during the year ended December 31, 2017. The Company identified a triggering event of impairment for Solana as a result of the generation of the plant having been lower than expected during 2017 related to an incident with electric transformers which took place in July 2017. This project is within the Renewable energy sector and North America geography. The Company therefore performed an impairment test as of December 31, 2017, which resulted in the recoverable amount (value in use) exceeding the carrying amount of the asset by 7%. To determine the value in use of the asset, a specific discount rate has been used in each year considering changes in the debt/equity leverage ratio over the useful life of this project, resulting in the use of a range of discount rates between 4.7% and 5.0%. An adverse change in the key assumptions which are individually used for the valuation would not lead to future impairment recognition; neither in case of a 5% decrease in generation over the entire remaining useful life (PPA) of the project nor in case of an increase of 50 basis points in the discount rate. b) The following table shows the movements of contracted concessional assets included in the heading “Contracted Concessional assets” for 2016: Cost Total as of January 1, 2016 10,126,023 Additions 6,346 Translation differences (68,199 ) Change in the scope of the consolidated financial statements 5,876 Reclassification and other movements (2,450 ) Total as of December 31, 2016 10,067,596 Accumulated amortization Total as of January 1, 2016 (825,126 ) Additions (332,925 ) Change in the scope of the consolidated financial statements (2,381 ) Translation differences 17,108 Total accum. amort. as of December 31, 2016 (1,143,324 ) Net balance at December 31, 2016 8,924,272 During 2016 contracted concessional assets decreased primarily due to the amortization charge for the year. Considering the low level of wind resources recorded since COD in Palmatir and Cadonal projects and the uncertainty around such level in the future, the Company identified a triggering event of impairment during the year 2016 in compliance with IAS 36, Impairment of Assets. As a result, impairment tests have been performed resulting in the recording of an impairment loss of $17,229 thousand and $3,101 thousand for the Cadonal and Palmatir projects, respectively, as of December 31, 2016. The impairment has been recorded within the line “Depreciation, amortization and impairment charges” of the consolidated income statement, decreasing the amount of “Contracted concessional assets” pertaining to the Renewable energy sector and South America geography. The recoverable amount considered is the value in use and amounts to $91,795 thousand and $123,912 thousand for Cadonal and Palmatir, respectively, as of December 31, 2016. A specific discount rate has been used in each year considering changes in the debt/equity leverage ratio over the useful life of this project, resulting in the use of a range of discount rates between 6.7% and 7.0% for both projects. An adverse change in the key assumptions which are individually used for the valuation could lead to future impairment recognition; especially, a 5% decrease in generation over the entire remaining useful life (PPA) of the project would generate an additional impairment of approximately $5 million for Cadonal and $7 million for Palmatir. An increase of 50 basis points in the discount rate would lead to an additional impairment of approximately $3 million for Cadonal and $4 million for Palmatir. In addition, the Company identified a triggering event of impairment for Solana as a result of the generation of the plant having been lower than expected during its first years of operation. This project pertains to the Renewable energy sector and North America geography. The Company therefore performed an impairment test as of December 31, 2016, which resulted in the recoverable amount (value in use) exceeding the carrying amount of the asset by 3%. To determine the value in use of the asset, a specific discount rate has been used in each year considering changes in the debt/equity leverage ratio over the useful life of this project, resulting in the use of a range of discount rates between 4.1% and 5.1%. An adverse change in the key assumptions which are individually used for the valuation could lead to future impairment recognition; especially, a 5% decrease in generation over the entire remaining useful life (PPA) of the project would generate an impairment of approximately $40 million. An increase of 50 basis points in the discount rate would lead to an impairment of approximately $30 million.

Investments carried under the e

Investments carried under the equity method	12 Months Ended
	Dec. 31, 2017
Investments carried under the equity method [Abstract]
Investments carried under the equity method	Note 7.- Investments carried under the equity method The table below shows the breakdown and the movement of the investments held in associates for 2017 and 2016: Investments in associates 2017 2016 Initial balance 55,009 56,181 Share of (loss)/profit 5,351 6,646 Dividend distribution (2,454 ) (3,954 ) Equity distribution (549 ) (3,099 ) Currency translation differences (1,573 ) (765 ) Final balance 55,784 55,009 There are no significant movement of the investments held in associates during the year 2017. The tables below show a breakdown of stand-alone amounts of assets, revenues and profit and loss as well as other information of interest for the years 2017 and 2016 for the associated companies: Company % Shares Non- current assets Current assets Non- current liabilities Current liabilities Revenue Operating profit/ (loss) Net profit/ (loss) Investment under the equity method Evacuación Valdecaballeros, S.L. 57.16 21,306 841 373 451 298 (708 ) (730 ) 9,175 Myah Bahr Honaine, S.P.A.(*) 25.50 195,275 64,114 91,205 12,649 46,767 28,468 24,464 43,365 Pectonex, R.F. Proprietary Limited 50.00 3,904 - - 2 - (206 ) (206 ) 3,244 Evacuación Villanueva del Rey, S.L 40.02 3,526 53 2,265 190 - 37 - - As of December 31, 2017 240,011 65,008 93,843 13,292 47,065 27,591 23,528 55,784 Company % Shares Non- current assets Current assets Non- current liabilities Current liabilities Revenue Operating profit/ (loss) Net profit/ (loss) Investment under the equity method Evacuación Valdecaballeros, S.L. 57.16 19,283 931 306 532 537 (545 ) (565 ) 9,528 Myah Bahr Honaine, S.P.A.(*) 25.50 202,150 67,120 104,704 14,158 52,770 34,247 29,990 42,056 Pectonex, R.F. Proprietary Limited 50.00 3,730 - - 1 - (187 ) (187 ) 3,425 Evacuación Villanueva del Rey, S.L 40.02 3,251 17 2,118 142 - 31 - - As of December 31, 2016 228,684 68,068 107,128 14,833 53,307 33,546 29,238 55,009 The Company has no control over Evacuación Valdecaballeros, S.L. as all relevant decisions of this company require the approval of a minimum of shareholders accounting for more than 75% of the shares. None of the associated companies referred to above is a listed company. (*) Myah Bahr Honaine, S.P.A., the project entity, is 51% owned by Geida Tlemcen, S.L. which is accounted for using the equity method in these consolidated financial statements. Share of profit of Myah Bahr Honaine S.P.A. included in these consolidated financial statements amounts to $6,238 thousand in 2017 and $7,647 thousand in 2016.

Financial instruments by catego

Financial instruments by category	12 Months Ended
	Dec. 31, 2017
Financial instruments by category [Abstract]
Financial instruments by category	Note 8.- Financial instruments by category Financial instruments are primarily deposits, derivatives, trade and other receivables and loans. Financial instruments by category (current and non-current), reconciled with the statement of financial position as of December 31, 2017 and 2016 are as follows: Notes Loans and receivables / payables Available for sale financial assets Hedging derivatives Balance as of December 31, 2017 Derivative assets 9 - - 8,230 8,230 Investment in Ten West Link 2,088 - - 2,088 Abengoa debt and Equity instruments - 1,715 - 1,715 Other financial investments 243,347 - - 243,347 Clients and other receivables 11 244,449 - - 244,449 Cash and cash equivalents 12 669,387 - - 669,387 Total financial assets 1,159,271 1,715 8,230 1,169,216 Corporate debt 14 643,083 - - 643,083 Project debt 15 5,475,208 - - 5,475,208 Related parties – non-current 10 141,031 - - 141,031 Trade and other current liabilities 17 155,144 - - 155,144 Derivative liabilities 9 - - 329,731 329,731 Total financial liabilities 6,414,466 - 329,731 6,744,197 Notes Loans and receivables / payables Available for sale financial assets Hedging derivatives Balance as of December 31, 2016 Derivative assets 9 - - 3,822 3,822 Preferred equity in ACBH - 30,488 - 30,488 Other financial investments 263,501 - - 263,501 Clients and other receivables 11 207,621 - - 207,621 Cash and cash equivalents 12 594,811 - - 594,811 Total financial assets 1,065,933 30,488 3,822 1,100,243 Corporate debt 14 668,201 - - 668,201 Project debt 15 5,330,467 - - 5,330,467 Related parties – non-current 10 101,750 - - 101,750 Trade and other current liabilities 17 160,505 - - 160,505 Derivative liabilities 9 - - 349,266 349,266 Total financial liabilities 6,260,923 - 349,266 6,610,189 Further to the completion of a series of conditions precedent that made Abengoa´s restructuring effective as of March 31, 2017, the guarantee provided by Abengoa regarding the preferred equity investment in ACBH, which supported the fair value of this instrument of $30.5 million as of December 31, 2016, was canceled, which reduced the fair value of this instrument to nil. In exchange for the guarantee provided by Abengoa being canceled, the Company received a certain amount of equity in Abengoa, and Corporate tradable bonds issued by Abengoa and subject to a 5.5-year period stay (extendable to a 2 additional years subject further to the senior old money creditors´consent) and with a 1.5% annual interest rate (0.25% cash, 1.25% PIK). Further to the restructuring agreement of Abengoa being made effective, the Company was assigned an amount of New Money 1 Tradable Notes of $44.5 million in exchange for contributing $43.6 million of cash. As a result of this contribution, the corporate tradable bonds detailed above are ranked as senior debt. The Company sold all the New Money 1 Tradable Notes it was assigned during the month of April 2017 for $44.9 million. New Money 1 Tradable Notes assigned to Atlantica Yield, Corporate tradable bonds and shares in Abengoa received, together are further referred as “Abengoa Debt and Equity Instruments”. These are all available for sale financial assets, of which major part has been sold during the second, third and fourth quarter of 2017. The fair value of the remaining portion as of December 31, 2017 amounts to $1.7 million, and is classified as current financial investments. Derecognition of the fair value assigned to the ACBH preferred equity investment and recognition of the Abengoa Debt and Equity Instruments resulted in a loss of $5.8 million. The sale of these instruments resulted in a profit of $6.5 million. Both impacts are accounted for in these consolidated financial statements for the year ended December 31, 2017 as Other net financial income and expenses (see Note 21). Prior to Abengoa´s restructuring agreement being made effective, Abengoa acknowledged that it failed to fulfill its obligations under the agreements related to the preferred equity investment in ACBH and, as a result, Atlantica Yield is the legal owner of the dividends amounting to $10.4 million declared on February 24, 2017, that the Company retained from Abengoa. Upon receipt of Abengoa Debt and Equity Instruments, the Company waived its rights under the guarantee provided by Abengoa related to the ACBH agreements, including its right to retain the dividends payable to Abengoa. Other financial investments include primarily the short-term portion of contracted concessional assets (see Note 6). Investment in Ten West Link as of December 31, 201 is a $2.1 million investment, which was made by the Company accounting for a 12.5% interests in a 114-mile transmission line in the U.S. As of December 31, 2017 and 2016, all the financial instruments measured at fair value have been classified as Level 2, except for the Abengoa Debt and Equity Instruments received further to the implementation of Abengoa´s restructuring agreement on March 31st 2017. The unsold portion as of December 31st 2017 is classified as Level 1.

Derivative financial instrument

Derivative financial instruments	12 Months Ended
	Dec. 31, 2017
Derivative financial instruments [Abstract]
Derivative financial instruments	Note 9.- Derivative financial instruments The breakdowns of the fair value amount of the derivative financial instruments as of December 31, 2017 and 2016 are as follows: Balance as of December 31, 2017 Balance as of December 31, 2016 Assets Liabilities Assets Liabilities Derivatives - cash flow hedge 8,230 329,731 3,822 349,266 The derivatives are primarily interest rate cash-flow hedges. All are classified as non-current assets or non-current liabilities, as they hedge long-term financing agreements. On May 12, 2015, the Company entered into a currency swap agreement with Abengoa which provided for a fixed exchange rate for the cash available for distribution from the Company’s Spanish assets. The distributions from the Spanish assets are paid in euros and the currency swap agreement provided for a fixed exchange rate at which euros will be converted into U.S. dollars. The currency swap agreement had a five-year term, and was valued by comparing the contracted exchange rate and the future exchange rate in the valuation scenario at the maturities dates. The instrument was valued by calculating the cash flow that would be obtained or paid by theoretically closing out the position and then discounting that amount. The Company terminated this agreement with Abengoa in October 2017 (see Note 21). Additionally, the Company signed during the year ended December 31, 2017, currency options with leading international financial institutions, which guarantee a minimum Euro-U.S. dollar exchange rates for the distributions expected from Spanish solar assets made in euros during the years 2017, 2018 and part of 2019. As stated in Note 3 to these consolidated financial statements, the general policy is to hedge variable interest rates of financing agreements purchasing call options (caps) in exchange of a premium to fix the maximum interest rate cost and contracting floating to fixed interest rate swaps. As a result, the notional amounts hedged, strikes contracted and maturities, depending on the characteristics of the debt on which the interest rate risk is being hedged, can be diverse: · Project debt in Euros: the Company hedges between 87% and 100% of the notional amount, maturities until 2030 and average guaranteed interest rates of between 3.20% and 4.87%. · Project debt in U.S. dollars: the Company hedges between 70% and 100% of the notional amount, including maturities until 2032 and average guaranteed interest rates of between 2.32% and 5.27%. The table below shows a breakdown of the maturities of notional amounts of derivatives designated as cash flow hedges as of December 31, 2017 and 2016. Notionals Balance as of December 31, 2017 Balance as of December 31, 2016 Cap Swap Cap Swap Up to 1 year 42,324 139,939 24,261 75,837 Between 1 and 2 years 45,422 94,285 25,934 199,832 Between 2 and 3 years 48,215 103,536 27,880 83,897 Subsequent years 620,378 1,893,850 400,239 1,500,789 Total $ 756,339 $ 2,231,611 $ 478,314 $ 1,860,355 The table below shows a breakdown of the maturity of the fair values of derivatives designated as cash flow hedges as of December 31, 2017 and 2016. The net position of the fair value of caps and swaps for each year end reconciles with the net position of derivative assets and derivative liabilities in the consolidated statement of financial position: Fair value Balance as of December 31, 2017 Balance as of December 31, 2016 Cap Swap Cap Swap Up to 1 year 347 (13,224 ) 250 (12,383 ) Between 1 and 2 years 978 (14,378 ) 262 (14,927 ) Between 2 and 3 years 396 (15,923 ) 275 (13,957 ) Subsequent years 6,509 (286,206 ) 3,035 (307,999 ) Total $ 8,230 (329,731 ) $ 3,822 (349,266 ) During 2017, fair value of derivatives increased mainly due to an increase in the fair value of interest rate cash-flow hedges resulting from the increase in future interest rates. The net amount of the fair value of interest rate derivatives designated as cash flow hedges transferred to the consolidated income statement is a loss of $70,953 thousand (loss of $72,774 thousand in 2016 and a loss of $55,841 thousand in 2015). Additionally, the net amount of the time value component of the cash flow derivatives fair value recognized in the consolidated income statement for the year 2017, 2016 and 2015 has been a loss of $860 thousand, a gain of $1,694 thousand and a gain of $4,234 thousand respectively. The after-tax result accumulated in equity in connection with derivatives designated as cash flow hedges at the years ended December 31, 2017 and 2016, amount to a $80,968 thousand gain and a $52,797 thousand gain respectively.

Related parties

Related parties	12 Months Ended
	Dec. 31, 2017
Related parties [Abstract]
Related parties	Note 10.- Related parties During the normal course of business, the Company has historically conducted operations with related parties consisting mainly of Abengoa´s subsidiaries and non-controlling interests. The transactions were completed at market rates. Details of balances with related parties as of December 31, 2017 and 2016 are as follows: Balance as of December 31, 2017 2016 Credit receivables (current) 11,567 12,031 Total current receivables with related parties 11,567 12,031 Credit receivables (non-current) 2,108 30,505 Total non-current receivables with related parties 2,108 30,505 Trade payables (current) 63,409 61,338 Total current payables with related parties 63,409 61,338 Credit payables (non-current) 141,031 101,750 Total non-current payables with related parties 141,031 101,750 Receivables from related parties as of December 31, 2017 include the remaining portion of Abengoa Debt and Equity Instruments received further to the implementation of Abengoa´s restructuring agreement, pending to be sold. These instruments are accounted for at fair value for $1,715 thousand as of December 31, 2017 and classified as current (see Note 8). As of December 31, 2016, receivables with related parties primarily corresponded to the preferred equity investment in ACBH for a total amount of $30,488 thousand, classified as non-current (see Note 8). Trade payables (current) primarily relate to payables for Operation and Maintenance services. Credit payables (non-current) primarily relate to payables of projects companies with partners accounted for as non-controlling interests in these consolidated financial statements. The transactions carried out by entities included in these consolidated financial statements with related parties not included in the consolidation perimeter of Atlantica Yield, primarily with Abengoa and with subsidiaries of Abengoa, during the twelve-month periods ended December 31, 2017, 2016 and 2015 have been as follows: For the year ended December 31, 2017 2016 2015 Sales - - 44,260 Services rendered 3,495 1,220 523 Services received (114,416 ) (115,779 ) (106,737 ) Financial income 74 60 1,466 Financial expenses (1,154 ) (2,460 ) (1,968 ) Services received primarily include operation and maintenance services received by some assets. Until December 2015, sales related to sale of energy by Spanish Solar plants were sometimes made through an Abengoa company acting as an agent for the plant. This service is not provided anymore by Abengoa since then. The figures detailed in the table above do not include the following financial income recorded in these consolidated financial statements for the year ended December 31, 2017: compensation received from Abengoa in lieu of dividends from ACBH for $10.4 million resulting from the agreement signed with Abengoa in the third quarter of 2016 (see Note 8). As of December 31, 2016, the figures do not include the compensation received from Abengoa in lieu of dividends from ACBH for $28.0 million, income for the cancellation of the subordinated debt Solnova Electricidad S.A. owed to Abener for $7.6 million and income of $1.7 million for discounts received from Abengoa for the prepayment of payables. In addition, Abengoa maintains a number of obligations under EPC, O&M and other contracts, as well as indemnities covering certain potential risks. Additionally, Abengoa represented that further to the accession to the restructuring agreement, Atlantica Yield would not be a guarantor of any obligation of Abengoa with respect to third parties and agreed to indemnify the Company for any penalty claimed by third parties resulting from any breach in such representations. The Company has contingent assets, which have not been recognized as of December 31, 2017, related to the obligations of Abengoa referred above, which result and amounts will depend on the occurrence of uncertain future events. As explained in Note 1, in November 2017 the Company signed a consent in relation to the Solana and Mojave projects which reduces the minimum ownership required by Abengoa in Atlantica Yield to 16%, subject to certain conditions precedent most of which are beyond the control of the Company, including several payments by Abengoa to Solana before December 2017 and February 2018 (subsequently this date was postponed to May 2018). These payments for a total of $120 million are related to Abengoa’s obligations as EPC contractor in Solana and would be used to repay Solana project debt ($80 million), for current and potential required additional repairs in the plant ($25 million) and for covering other Abengoa obligations ($15 million). Additionally, Abengoa has recognized other obligations with Solana for $6.5 million per semester over 10 years starting in December 2018. In December 2017 Solana received $42.5 million related to Abengoa´s obligation as EPC contractor. The aforementioned amounts are based on the EPC Contract guarantee for liquidated damages considering the average production during the first three years of ramp-up period of the plant which is a service-concession arrangement under IFRIC 12 (intangible asset). For the $42.5 million collected before the end of December 2017, the Company reduced the value of the intangible asset since this amount was a variable consideration. The rest of the amounts to be paid by Abengoa after December 31, 2017 will be accounted for in the same manner, as a reduction of the value of the asset when the different installments are collected. In addition, the amortization of the plant will also be adjusted accordingly. The Company entered into a Financial Support Agreement on June 13, 2014 under which Abengoa agreed to maintain any guarantees and letters of credit that have been provided by it on behalf of or for the benefit of Atlantica Yield and its affiliates for a period of five years In the context of that agreement in which Atlantica Yield agreed that it shall use commercially reasonable efforts to replace guarantees, on June 2017, it agreed to replace guarantees amounting to $112 million previously issued by Abengoa. During the third quarter of 2017, the Company issued the aforementioned guarantees and received from Abengoa a payment of €7.8 million for existing debts. At the date of the initial offering, the Company entered into a series of agreements to receive management, general and administrative services from Abengoa (the “Support Services Agreement” and “Executive Service Agreement”), and corresponding fees were properly accounted for as other operating expenses. The Executive Service Agreement was canceled in February 2015. During the year 2015 and 2016, some employees of Abengoa delivering services under the Support Services Agreement were transferred to entities within the consolidation perimeter of Atlantica Yield and the Support Services Agreement was cancelled. In addition, some external employees were hired. This resulted in the Company increasing its employee benefit expenses as shown in the consolidated income statement for the years 2015, 2016 and 2017.

Clients and other receivable

Clients and other receivable	12 Months Ended
	Dec. 31, 2017
Clients and other receivable [Abstract]
Clients and other receivable	Note 11.- Clients and other receivable Clients and other receivable as of December 31, 2017 and 2016, consist of the following: Balance as of December 31, 2017 2016 Trade receivables 186,728 151,199 Tax receivables 39,607 29,705 Prepayments 6,375 10,261 Other accounts receivable 11,739 16,456 Total 244,449 207,621 As of December 31, 2017 and 2016, the fair value of clients and other accounts receivable does not differ significantly from its carrying value. Trade receivables in foreign currency as of December 31, 2017 and 2016, are as follows: Balance as of December 31, 2017 2016 Euro 109,165 98,798 Rand 23,792 12,807 Other 7,363 7,151 Total 140,320 118,756 The following table shows the maturity of Trade receivables as of December 31, 2017 and 2016: Balance as of December 31, 2017 2016 Up to 3 months 186,728 151,199 Total 186,728 151,199

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Dec. 31, 2017
Cash and cash equivalents [Abstract]
Cash and cash equivalents	Note 12.- Cash and cash equivalents The following table shows the detail of Cash and cash equivalents as of December 31, 2017 and 2016: Balance as of December 31, 2017 2016 Cash at bank and on hand 669,387 594,811 Total 669,387 594,811 Cash includes funds held to satisfy the customary requirements of certain non-recourse debt agreements within the Company´s projects amounting to $263 million. The following breakdown shows the main currencies in which cash and cash equivalent balances are denominated: Balance as of December 31, Currency 2017 2016 U.S. dollar 319,400 343,954 Euro 288,625 196,382 Algerian Dinar 13,628 10,736 South African Rand 40,999 39,689 Others 6,735 4,050 Total 669,387 594,811

Equity

Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Equity	Note 13.- Equity On June 18, 2014, Atlantica Yield closed its initial public offering issuing 24,850,000 ordinary shares. The shares were sold at a price of $29 per share and as a result the Company raised $720,650 thousand of gross proceeds. The Company recorded $2,485 thousand as Share Capital and $682,810 thousand as Additional Paid in Capital, included in Atlantica Yield reserves as of December 31, 2016, corresponding to the total net proceeds of the offering. The underwriters further purchased 3,727,500 additional shares from the selling shareholder, a subsidiary wholly owned by Abengoa, at the public offering price less fees and commissions to cover over-allotments (“greenshoe”) driving the total proceeds of the offering to $828,748 thousand. Atlantica Yield’s shares began trading on the NASDAQ Global Select Market under the symbol “ABY” on June 13, 2014. The symbol changed to “AY” on November 11, 2017. On January 22, 2015, Abengoa closed an underwritten public offering and sale in the United States of 10,580,000 of ordinary shares of the Company for total proceeds of $327,980,000 (or $31 per share). As a result of such offering, Abengoa reduced its stake in the Company from 64.3% to 51.1% of its shares. On May 14, 2015 Atlantica Yield issued 20,217,260 new shares at $33.14 per share, which was based on a 3% discount versus the May 7, 2015 closing price. Abengoa subscribed for 51% of the newly-issued shares and maintained its previous stake in Atlantica Yield. The proceeds were primarily used by Atlantica Yield to finance asset acquisitions in May and June 2015. On July 14, 2015, Abengoa sold 2,000,000 shares of Atlantica Yield under Rule 144, reducing its stake to 49.1%. As of the date hereof, according to Abengoa´s beneficial ownership reporting, Abengoa has delivered an aggregate of 7,595,639 Ordinary Shares to holders that exercised their option to exchange the $279,000 thousand principal amount of exchangeable notes due 2017 issued by Abengoa on March 5, 2015 (the “Exchangeable Notes”) for shares of Atlantica Yield. The Exchangeable Notes are exchangeable, at the option of their holders, for ordinary shares of Atlantica Yield. These operations reduced Abengoa´s stake to 41.47% as of December 31, 2017. As of December 31, 2017, the share capital of the Company amounts to $10,021,726 represented by 100,217,260 ordinary shares completely subscribed and disbursed with a nominal value of $0.10 each, all in the same class and series. Each share grants one voting right. Atlantica Yield reserves as of December 31, 2017 are made up of share premium account and distributable reserves. Retained earnings include results attributable to Atlantica Yield, the impact of the Asset Transfer in equity and the impact of the assets acquisition under the ROFO agreement in equity. The Asset Transfer and the acquisitions under the ROFO agreement were recorded in accordance with the Predecessor accounting principle, given that all these transactions occurred before December 2015, when Abengoa still had control over Atlantica Yield. Non-controlling interests fully relate to interests held by JGC in Solacor 1 and Solacor 2, by Idae in Seville PV, by Itochu Corporation in Solaben 2 and Solaben 3, by Algerian Energy Company, SPA and Valoriza Agua S.L. in Skikda and by Industrial Development Corporation of South Africa (IDC) and Kaxu Community Trust in Kaxu Solar One (Pty) Ltd. Additional information of subsidiaries including material Non-controlling interests as of December 31, 2017 and 2016, are disclosed in Appendix IV. Dividends declared during the year 2017: - On February 27, 2017, the Board of Directors declared a dividend of $0.25 per share corresponding to the four quarter of 2016. The dividend was paid on March 15, 2017. From that amount, the Company retained $10.4 million of the dividend attributable to Abengoa; - On May 15, 2017, the Board of Directors declared a dividend of $0.25 per share corresponding to the first quarter of 2017. The dividend was paid on June 15, 2017; - On August 3, 2017, the Board of Directors declared a dividend of $0.26 per share corresponding to the second quarter of 2017. The dividend was paid on September 15, 2017; - On November 13, 2017, the Board of Directors declared a dividend of $0.29 per share corresponding to the third quarter of 2017. The dividend was paid on December 15, 2017. In addition, as of December 31, 2017, there was no treasury stock and there have been no transactions with treasury stock during the period then ended.

Corporate debt

Corporate debt	12 Months Ended
	Dec. 31, 2017
Corporate debt [Abstract]
Corporate debt	Note 14.- Corporate debt The breakdown of the corporate debt as of December 31, 2017 and 2016 is as follows: Balance as of December 31, Non-current 2017 2016 Credit Facilities with financial entities 320,783 123,804 Notes and Bonds 253,393 252,536 Total Non-Current 574,176 376,340 Balance as of December 31, Current 2017 2016 Credit Facilities with financial entities 65,833 289,035 Notes and Bonds 3,074 2,826 Total Current 68,907 291,861 On November 17, 2014, the Company issued the Senior Notes due 2019 in an aggregate principal amount of $255,000 thousand (the “2019 Notes”). The 2019 Notes accrue annual interest of 7.00% payable semi-annually beginning on May 15, 2015 until their maturity date of November 15, 2019. On December 3, 2014, the Company entered into a credit facility of up to $125,000 thousand with Banco Santander, S.A., Bank of America, N.A., Citigroup Global Markets Limited, HSBC Bank plc and RBC Capital Markets, as joint lead arrangers and joint bookrunners (the “Credit Facility Tranche A”). On December 22, 2014, the Company drew down $125,000 thousand under the Credit Facility Tranche A. Loans accrue interest at a rate per annum equal to: (A) for Eurodollar rate loans, LIBOR plus 2.75% and (B) for base rate loans, the highest of (i) the rate per annum equal to the weighted average of the rates on overnight U.S. Federal funds transactions with members of the U.S. Federal Reserve System arranged by U.S. Federal funds brokers on such day plus 1/2 of 1.00%, (ii) the U.S. prime rate and (iii) LIBOR plus 1.00%, in any case, plus 1.75%. The interest rate on the Credit Facility Tranche A is fully hedged by an interest rate swap contracted with HSBC Bank with maturity date December 24, 2018, resulting in the Company paying a net fixed interest rate of 4.7%. Loans under the Credit Facility Tranche A will mature in December 2018. Loans prepaid by the Company may be reborrowed. The Credit Facility Tranche A is secured by pledges of the shares of the guarantors which the Company owns. $8,000 thousand of the loans under the Credit Facility Tranche A were partially repaid on September 25, 2017 and for $63,000 thousand on December 27, 2017. As of December 31, 2017, the remaining $54,000 of nominal of the Tranche A has been classified as Current (Non-Current as of December 31,2016), as its maturity is in December 2018. On June 26, 2015, the Company increased its existing $125 million Credit Facility with a revolver tranche B for an amount of $290,000 thousand (the “Credit Facility Tranche B”). On September 9, 2015, Credit Facility Tranche B was fully drawn down and the proceeds were used for the acquisition of Solaben 1/6. Loans under the Tranche B Credit Facility accrue interest at a rate per annum equal to: (A) for Eurodollar rate loans, LIBOR plus 2.50% and (B) for base rate loans, the highest of (i) the rate per annum equal to the weighted average of the rates on overnight U.S. Federal funds transactions with members of the U.S. Federal Reserve System arranged by U.S. Federal funds brokers on such day plus 1/2 of 1.00%, (ii) the U.S. prime rate and (iii) LIBOR plus 1.00%, in any case, plus 1.50%. Tranche B of the Credit Facility was signed for a total amount of $290,000 thousand with Bank of America, N.A., as global coordinator and documentation agent and Barclays Bank plc and UBS AG, London Branch as joint lead arrangers and joint bookrunners. The Credit Facility Tranche B was classified as Current for $288,317 thousand as of December 31, 2016 (Non-Current as of December 31,2015) as it matured in December 2017. Loans under the Credit facility Tranche B were fully repaid and canceled on February 28, 2017. On February 10, 2017, the Company issued Senior Notes due 2022, 2023, 2024 (the “Note Issuance Facility”), in an aggregate principal amount of €275,000 thousand. The 2022 to 2024 Notes accrue annual interest, equal to the sum of (i) EURIBOR plus (ii) 4.90%, as determined by the Agent. Interest on the Notes will be payable in cash quarterly in arrears on each interest payment date. The Company will make each interest payment to the holders of record on each interest payment date. The interest rate on the Note Issuance Facility is fully hedged by two interest rate swaps contracted with Jefferies Financial Services, Inc. with effective On July 20, 2017, the Company signed a credit facility (the “Credit Facility 2017”) for up to €10 million, approximately $11.9 million, which is available in euros or US dollars. Amounts drawn accrue interest at a rate per year equal to EURIBOR plus 2.25% or LIBOR plus 2.25%, depending on the currency. The credit facility has a maturity date of July 20, 2018. As of December 31, 2017, the Company drew down the credit facility in full and used the entire proceeds to prepay a part of the Tranche A of the Credit Facility. Current corporate debt corresponds to the accrued interest on the Notes, to the outstanding amount of the Tranche A and to the amount of the Credit Facility obtained in July 2017. The repayment schedule for the Corporate debt, at the end of 2017 is as follows: 2018 2019 2020 2021 2022 Subsequent years Total Credit Facility Tranche A 53,778 - - - - - 53,778 Note Issuance Facility 107 - - - 107,316 213,467 320,890 Credit Facility 2017 11,948 - - - - - 11,948 2019 Notes 3,074 253,393 - - - - 256,467 Total 68,907 253,393 - - 107,316 213,467 643,083 The following table details the movement in Corporate debt for the year 2017, split between cash and non-cash items: January 1, 2017 Cash Flow Non-cash changes December 31, 2017 Corporate debt 668,201 (68,372 ) 43,254 643,083 The non-cash changes primarily relates to currency translation differences.

Project debt

Project debt	12 Months Ended
	Dec. 31, 2017
Project debt [Abstract]
Project debt	Note 15.- Project debt The main purpose of the Company is the long-term ownership and management of contracted concessional assets, such as renewable energy, efficient natural gas, electric transmission line assets and water, which are financed through project debt. This Note shows the project debt linked to the contracted concessional assets included in Note 6 of these consolidated financial statements. Project debt is generally used to finance contracted assets, exclusively using as guarantee the assets and cash flows of the company or group of companies carrying out the activities financed. In most of the cases, the assets and/or contracts are set up as guarantee to ensure the repayment of the related financing. Compared with corporate debt, project debt has certain key advantages, including greater leverage period permitted and a longer tenor. The variations for 2017 and 2016 of project debt have been the following: Project debt - long term Project debt - short term Total Balance as of December 31, 2016 4,629,184 701,283 5,330,467 Increases 52,027 304,707 356,734 Decreases (42,560 ) (509,131 ) (551,691 ) Currency translation differences 316,646 23,052 339,698 Reclassifications 273,620 (273,620 ) - Balance as of December 31, 2017 5,228,917 246,291 5,475,208 The line “Increases” includes primarily accrued interests for the year. Main variations in Project debt during the year 2017 are the result of: - Net decrease primarily due to repayment of debt, considering that interests accrued are offset by a similar amount of interests paid during the year. Decrease in long-term debt primarily relates to the partial repayment of Solana debt using the indemnity received from Abengoa in December 2017 for $42.5 million (see Note 10); - A reclassification of the entire debt of Kaxu and Cadonal projects from short term to long term during the year 2017 as a result of the waiver obtained for Kaxu in March 2017 and the completion of certain pending conditions for Cadonal in October 2017. In addition, in 2017, Kaxu’s debt coverage ratio did not reach the minimum threshold due to the technical problems that the plant experienced since the end of 2016. However, the lenders of the project finance agreement granted a waiver to the asset and therefore reclassification of the debt to short-term does not apply in this case. Project debt - long term Project debt - short term Total Balance as of December 31, 2015 3,574,464 1,896,205 5,470,669 Increases 36,842 329,434 366,276 Decreases - (480,969 ) (480,969 ) Currency translation differences (64,426 ) 38,917 (25,509 ) Reclassifications 1,082,304 (1,082,304 ) - Balance as of December 31, 2016 4,629,184 701,283 5,330,467 The line “Increases” includes primarily accrued interests for the year. Main variations in Project debt during the year 2016 were the result of: - Net decrease primarily due to repayment of debt; considering that interests accrued were offset by a similar amount of interests paid during the year; - A reclassification of the entire debt of Solana and Mojave projects from short term to long term as of December 31, 2016 considering that as a result of the forbearance signed in December 2016, Abengoa cross-defaults will no longer trigger acceleration remedies in the Solana or Mojave financing agreements. Debts of Kaxu and Cadonal projects remained classified as short term in accordance with International Accounting Standards 1 (“IAS 1”), “Presentation of Financial Statements” as of December 31, 2016. The waiver of the cross-default provisions related to Abengoa that had been obtained for Cadonal during 2016 was subject to the completion of certain conditions. The repayment schedule for Project debt in accordance with the financing arrangements, at the end of 2017 is as follows and is consistent with the projected cash flows of the related projects. 2018 2019 2020 2021 2022 Subsequent years Total Interest Repayment Nominal repayment 21,612 224,679 246,471 265,002 280,303 313,559 4,123,582 5,475,208 In 2016, the Company refinanced ATN2 debt. In 2017, the Company did not enter into any new project debt. Current and non-current loans with credit entities include amounts in foreign currencies for a total of $2,778,043 thousand as of December 31, 2017 ($2,564,291 thousand as of December 31, 2016). The following table details the movement in Project debt for the year 2017, split between cash and non-cash items: January 1, 2017 Cash Flow Non-cash changes December 31, 2017 Project debt 5,330,467 (248,472 ) 393,212 5,475,208 The non-cash changes primarily relates to currency translation differences. The equivalent in U.S. dollars of the most significant foreign-currency-denominated debts held by the Company is as follows: Balance as of December 31, Currency 2017 2016 Euro 2,286,771 2,102,985 Algerian Dinar 35,093 41,598 Rand 456,179 419,708 Total 2,778,043 2,564,291 All of the Company’s financing agreements have a carrying amount close to its fair value.

Grants and other liabilities

Grants and other liabilities	12 Months Ended
	Dec. 31, 2017
Grants and other liabilities [Abstract]
Grants and other liabilities	Note 16.- Grants and other liabilities Balance as of December 31, 2017 2016 Grants 1,225,877 1,297,755 Other liabilities 410,183 314,290 Grant and other non-current liabilities 1,636,060 1,612,045 As of December 31, 2017, the amount recorded in Grants corresponds primarily to the ITC Grant awarded by the U.S. Department of the Treasury to Solana and Mojave for a total amount of $771 million ($803 million as of December 31, 2016), which was primarily used to fully repay the Solana and Mojave short-term tranche of the loan with the Federal Financing Bank. The amount recorded in Grants as a liability is progressively recorded as other income over the useful life of the asset. The remaining balance of the “Grants” account corresponds to loans with interest rates below market rates for Solana and Mojave for a total amount of $452 million ($492 million as of December 31, 2016). Loans with the Federal Financing Bank guaranteed by the Department of Energy for these projects bear interest at a rate below market rates for these types of projects and terms. The difference between proceeds received from these loans and its fair value, is initially recorded as “Grants” in the consolidated statement of financial position, and subsequently recorded in “Other operating income” starting at the entry into operation of the plants. Total amount of income for these two types of grants for Solana and Mojave is $59.8 million and $57.0 million for the year ended December 31, 2017 and 2016, respectively. Other liabilities mainly relate to the investment from Liberty Interactive Corporation (‘Liberty’) made on October 2, 2013 for an amount of $300 million. The investment was made in class A shares of Arizona Solar Holding, the holding of Solana Solar plant in the United States. Such investment was made in a tax equity partnership which permits the partners to have certain tax benefits such as accelerated depreciation and ITC. According to the stipulations of IAS 32 and in spite of the fact that the investment of Liberty is in shares, it does not qualify as equity and has been classified as a liability as of December 31, 2017 and 2016. The liability is recorded in Grants and other liabilities for a total amount of $352 million ($263 million as of December 31, 2016) and its current portion is recorded in other current liabilities for the remaining amount (see Note 17).

Trade payables and other curren

Trade payables and other current liabilities	12 Months Ended
	Dec. 31, 2017
Trade payables and other current liabilities [Abstract]
Trade payables and other current liabilities	Note 17.- Trade payables and other current liabilities Trade payable and other current liabilities as of December 31, 2017 and 2016 are as follows: Balance as of December 31, Item 2017 2016 Trade accounts payables 107,662 121,527 Down payments from clients 6,466 6,153 Suppliers of concessional assets current 236 380 Liberty (see Note 16) - 21,461 Other accounts payable 40,780 10,984 Total 155,144 160,505 Trade accounts payables mainly relate to the operating and maintenance of the plants. Nominal values of Trade payable and other current liabilities are considered to approximately equal to fair values and the effect of discounting them is not significant. Other account payable primarily include subordinated debt of Mojave with Abener Teyma Mojave General Partnership (Abener), a related party, with maturity date on October 2018. The repayment will occur if certain technical conditions are fulfilled.

Income Tax

Income Tax	12 Months Ended
	Dec. 31, 2017
Income Tax [Abstract]
Income Tax	Note 18.- Income Tax All the companies included in the Company file income taxes according to the tax regulations in force in each country on an individual basis or under consolidation tax regulations. The consolidated income tax has been calculated as an aggregation of income tax expenses/income of each individual company. In order to calculate the taxable income of the consolidated entities individually, the accounting result is adjusted for temporary and permanent differences, recording the corresponding deferred tax assets and liabilities. At each consolidated income statement date, a current tax asset or liability is recorded, representing income taxes currently refundable or payable. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial statement and income tax purposes, as determined under enacted tax laws and rates. Income tax payable is the result of applying the applicable tax rate in force to each tax-paying entity, in accordance with the tax laws in force in the country in which the entity is registered. Additionally, tax deductions and credits are available to certain entities, primarily relating to inter-company trades and tax treaties between various countries to prevent double taxation. As of December 31, 2017, and 2016, the analysis of deferred tax assets and deferred tax liabilities is as follows: Deferred tax assets Balance as of December 31, Concept 2017 2016 Net tax credits for operating losses carryforwards 71,219 102,804 Temporary differences derivatives financial instruments 93,719 99,930 Other temporary differences 198 157 Total deferred tax assets 165,136 202,891 Most of the net tax credits for operating losses carryforwards corresponds to Peru, Kaxu and solar plants in Spain as of December 31, 2017. The balance as of December 31, 2016 also included significant net deferred tax assets for Solana and Mojave, which are now net deferred tax liabilities as of December 31, 2017, due to the following: - In December 2017 a tax reform, the Tax Cuts and Jobs Act, was enacted in the U.S., consisting mainly in a decrease in the corporate tax rate from 35% to 21% effective 1st of January 2018. The Company therefore adjusted the deferred tax assets and liabilities of its U.S. entities using the new enacted corporate tax rate as of December 31, 2017, resulting in a loss of $19 million recorded in the consolidated income statement for the year ended December 31, 2017; - In addition, the U.S. Internal Revenue Code (“IRC”) Section 382 establishes an annual limitation on the use of U.S. Net Operating Losses (“NOLs”) as a result of an ownership change. An “ownership change” would occur if the direct and indirect “5-percent shareholders”, as defined under Section 382 of the IRC, collectively increased their ownership in the Company by more than 50 percentage points over a rolling three-year period. The Company experienced during 2017 an ownership change due to Abengoa´s restructuring and changes in its shareholders´s base. As a result, the U.S. NOLs carryforwards generated through the date of change are subject to an annual limitation under Section 382, which resulted in a derecognition of deferred tax assets previously recognized amounting to $96 million corresponding to an amount of $387 million of NOLs and also taking into consideration the newly enacted corporate tax rate of 21%. This loss has been recorded in the consolidated income statement for the year ended December 31, 2017. Temporary differences for derivatives financial instruments are mainly due to ACT ($18 million) and solar plants in Spain ($69 million). In relation to tax loss carryforwards and deductions pending to be used recorded as deferred tax assets, the entities evaluate its recoverability projecting forecasted taxable income for the upcoming years and taking into account their tax planning strategy. Deferred tax liabilities reversals are also considered in these projections, as well as any limitation established by tax regulations in force in each tax jurisdiction. Deferred tax liabilities Balance as of December 31, Concept 2017 2016 Temporary differences tax/book amortization 113,432 28,810 Other temporary differences tax/book value of contracted concessional assets 66,247 61,818 Other temporary differences 6,904 4,409 Total deferred tax liabilities 186,583 95,037 As of December 31, 2017, temporary differences as a result of accelerated tax amortization resulted in a net deferred tax liability position. These are primarily due to Solana and Mojave ($63 million) and solar plants in Spain ($51 million). The increase is primarily due to an impact on the U.S. entities as a result of the tax reform and U.S. Internal Revenue Code Section 382 as previously described. Other temporary differences tax/book value of contracted concessional assets, which resulted in a net deferred tax liability position relates primarily to ACT in both periods. The movements in deferred tax assets and liabilities during the years ended December 31, 2017 and 2016 were as follows: Deferred tax assets Amount As of January 1, 2016 191,314 Increase/decrease through the consolidated income statement 16,033 Increase/decrease through other consolidated comprehensive income (equity) (5,701 ) Other movements 1,245 As of December 31, 2016 202,891 Increase/decrease through the consolidated income statement (31,421 ) Increase/decrease through other consolidated comprehensive income (equity) (13,312 ) Other movements 6,978 As of December 31, 2017 165,136 Deferred tax liabilities Amount As of January 1, 2016 79,654 Increase/decrease through the consolidated income statement 16,681 Increase/decrease through other consolidated comprehensive income (equity) (62 ) Other movements (1,236 ) As of December 31, 2016 95,037 Increase/decrease through the consolidated income statement 86,418 Increase/decrease through other consolidated comprehensive income (equity) - Other movements 5,128 As of December 31, 2017 186,583 Details for income tax for the years ended December 31, 2017, 2016 and 2015 are as follows: For the twelve-month period ended December 31, Item 2017 2016 2015 Current tax (1,998 ) (1,018 ) (2,182 ) Deferred tax (117,839 ) (648 ) (21,608 ) - relating to the origination and reversal of temporary differences (98,508 ) (648 ) (22,492 ) - relating to changes in tax rates (19,331 ) - 884 Total income tax benefit/(expense) (119,837 ) (1,666 ) (23,790 ) The reconciliation between the theoretical income tax resulting from applying an average statutory tax rate to income/(loss) before income tax and the actual income tax expense recognized in the consolidated income statements for the years ended December 31, 2017, 2016 and 2015, are as follows: For the year ended December 31, Concept 2017 2016 2015 Consolidated income / (loss) before taxes 14,950 3,333 (174,396 ) Average statutory tax rate 30 % 30 % 30 % Corporate income tax at average statutory tax rate (4,485 ) (1,000 ) 52,319 Income tax of associates, net 1,765 2,110 2,341 Differences in foreign tax rates 3,304 (4,930 ) (2,389 ) Permanent differences 19,324 11,121 (19,456 ) Incentives, deductions, and unrecognized tax losses carryforwards (20,994 ) (11,110 ) (58,039 ) Change in corporate income tax (19,331 ) - 884 U.S. Internal Revenue Code Section 382 (96,328 ) - - Other non-taxable income/(expense) (3,092 ) 2,143 550 Corporate income tax (119,837 ) (1,666 ) (23,790 ) Permanent differences in 2017, 2016 and 2015 are mainly due to ACT (Mexico). The main implications derived from the Tax Cuts and Jobs Act in the U.S. entities are: - A reduction of the Federal income tax rate from 35% to 21%, effective since January 1, 2018. This measure will imply a reduction of the tax burden of the Company. The effect on the deferred tax assets and liabilities has resulted in a $19 million loss; - A limitation of the deduction for net interest expense of all businesses in the U.S. The new limitation is imposed on net interest expense that exceeds 30% of EBITDA from 2018 to 2021, and 30% of EBIT from 2022 onwards. Interests disallowed would be deducted in the future in the event that those limits are not exceeded. After having considered the impacts of Section 382 commented above, the Company does not expect significant negative effects from this net interest expense limitation; - NOLs arising in tax years beginning after 2017 would be limited to 80% of taxable income. For new NOLs recognized after 2017, an indefinite carryforward would be allowed. The limitation of 80% is not applicable for NOLs generated before 2018. For existing NOLs before 2018, a carryforward of 20 years is still applicable. The new limitation does not trigger adverse tax effects to the U.S. subsidiaries of the Company considering the amount of NOLs to be generated in upcoming years and the projected amount of taxable income of these entities after having considered the impacts of Section 382; - Base erosion anti-abuse tax (BEAT): The BEAT applies to certain U.S. corporations that make relevant deductible payments to foreign affiliates. The excess of 10% of a corporation’s taxable income increased by those payments to foreign related parties over its regular tax liability, will be the base erosion tax due. BEAT provisions do not trigger adverse tax consequences for the U.S. subsidiaries of the Company considering the amount of payments made to foreign affiliates for management and support services; - Potential tax erosion in the U.S.: The Company does not expect to have material adverse tax consequences in the U.S. subsidiaries as a result of the measures previously described.

Third-party guarantees and comm

Third-party guarantees and commitments	12 Months Ended
	Dec. 31, 2017
Third-party guarantees and commitments [Abstract]
Third-party guarantees and commitments	Note 19.- Third-party guarantees and commitments Third-party guarantees At the close of 2017 the overall sum of Bank Bond and Surety Insurance directly deposited by the subsidiaries of the Company as a guarantee to third parties (clients, financial entities and other third parties) amounted to $32,428 thousand attributed to operations of technical nature ($27,163 thousand as of December 31, 2016). In addition, in the third quarter of 2017 the Company issued the guarantees amounting to $112 million previously issued by Abengoa related to operations of technical nature (see Note 10). Contractual obligations The following table shows the breakdown of the third-party commitments and contractual obligations as of December 31, 2017 and 2016: 2017 Total 2018 2019 and 2020 2021 and 2022 Subsequent Corporate debt 643,083 68,907 253,393 107,316 213,467 Loans with credit institutions (project debt) 4,628,289 215,117 457,853 539,466 3,415,853 Notes and bonds (project debt) 846,919 31,174 53,620 54,395 707,730 Purchase commitments 3,149,813 141,867 230,014 259,845 2,518,087 Accrued interest estimate during the useful life of loans 3,129,321 340,481 630,108 559,856 1,598,876 2016 Total 2017 2018 and 2019 2020 and 2021 Subsequent Corporate debt 668,201 291,861 376,340 - - Loans with credit institutions (project debt)* 4,498,930 183,929 388,679 459,361 3,466,961 Notes and bonds (project debt) 831,538 27,225 49,422 48,740 706,151 Purchase commitments 2,894,146 136,032 263,398 246,904 2,247,812 Accrued interest estimate during the useful life of loans 3,356,750 332,408 617,852 543,927 1,862,563 * According to contracted maturities. Legal Proceedings On October 17, 2016, ACT received a request for arbitration from the International Court of Arbitration of the International Chamber of Commerce presented by Pemex. Pemex is requesting compensation for damages caused by a fire that occurred in their facilities during the construction of the ACT cogeneration plant in December 2012, for a total amount of approximately $20 million. On July 5, 2017, Seguros Inbursa, the insurer of Pemex, joined as a second claimant in the process. The Company does not expect this proceeding to have a material adverse effect on their financial position, cash flows or results of operations. In the event that the arbitration results in a negative outcome, the Company expects these damages to be covered by the existing insurance policy. A number of Abengoa's subcontractors and insurance companies that issued bonds covering such contracts in the United States have included subsidiaries of the Company as co-defendants in claims against Abengoa. Generally, the subsidiaries of the Company have been dismissed as defendants at early stages of the processes but there remain pending cases including Arb Inc. with a potential total claim of approximately $33 million and a group of insurance companies with a potential total claim of approximately $200 million. Based on the assessment of the Company with information currently available, the Company does not expect these proceedings, individually or in the aggregate, to have a material adverse effect on its financial position, cash flows or results of operations. The Company is not a party to any other significant legal proceeding other than legal proceedings arising in the ordinary course of its business. The Company is party to various administrative and regulatory proceedings that have arisen in the ordinary course of business. While the Company does not expect these proceedings, either individually or in the aggregate, to have a material adverse effect on its financial position or results of operations, because of the nature of these proceedings the Company is not able to predict their ultimate outcomes, some of which may be unfavorable to the Company.

Other operating income and expe

Other operating income and expenses	12 Months Ended
	Dec. 31, 2017
Other operating income and expenses [Abstract]
Other operating income and expenses	Note 20.- Other operating income and expenses The table below shows the detail of Other operating income and expenses for the years ended December 31, 2017, 2016 and 2015: For the twelve-month year ended December 31, Other operating income 2017 2016 2015 Grants 59,707 59,085 67,859 Income from various services and insurance proceeds 21,137 6,453 998 Total 80,844 65,538 68,857 For the twelve-month year ended December 31, Other operating expenses 2017 2016 2015 Leases and fees (6,641 ) (5,309 ) (3,865 ) Operation and maintenance (129,873 ) (133,292 ) (116,405 ) Independent professional services (36,178 ) (30,515 ) (19,046 ) Supplies (20,350 ) (17,177 ) (18,001 ) Insurance (24,289 ) (23,390 ) (20,277 ) Levies and duties (52,409 ) (44,440 ) (32,352 ) Other expenses (14,721 ) (6,195 ) (14,882 ) Total (284,461 ) (260,318 ) (224,828 ) Grants income mainly relate to ITC cash grants and implicit grants recorded for accounting purposes in relation to the FFB loans with interest rates below market rates in Solana and Mojave projects (See Note 16). Residual increase in other operating income relates primarily to insurance proceeds from claims in some assets of the Company. The Company changed the presentation of “Other operating expenses” in 2016 to better reflect the nature of its business and costs. Prior years amounts have been reclassified to conform to the new classification presented in the table above.

Financial Income and expenses

Financial Income and expenses	12 Months Ended
	Dec. 31, 2017
Financial income and expenses [Abstract]
Financial Income and expenses	Note 21.- Financial Income and expenses The following table sets forth financial income and expenses for the years ended December 31, 2017, 2016 and 2015: For the year ended December 31, Financial income 2017 2016 2015 Interest income from loans and credits 325 286 933 Interest rates benefits derivatives: cash flow hedges 682 3,012 2,531 Total 1,007 3,298 3,464 For the year ended December 31, Financial expenses 2017 2016 2015 Expenses due to interest: - Loans from credit entities (253,660 ) (242,919 ) (197,929 ) - Other debts (137,562 ) (90,995 ) (81,853 ) Interest rates losses derivatives: cash flow hedges (72,495 ) (74,093 ) (54,139 ) Total (463,717 ) (408,007 ) (333,921 ) Interests from other debts are primarily interest on the notes issued by ATS, ATN, ATN2, Atlantica Yield and Solaben Luxembourg and interest related to the investment from Liberty. Increase in 2017 is primarily due to the higher increase in the amortized cost of the Liberty debt by $50 million compared to the year 2016 (see Note 16). Losses from interest rate derivatives designated as cash flow hedges correspond primarily to transfers from equity to financial expense when the hedged item is impacting the consolidated income statement. Other net financial income and expenses The following table sets out Other net financial income and expenses for the years 2017, 2016 and 2015: For the year ended December 31, Other financial income / (expenses) 2017 2016 2015 Dividend from ACBH (Brazil) 10,383 27,948 18,400 Impairment preferred equity investment in ACBH (see Note 8) - (22,076 ) (210,435 ) Other financial income 28,809 13,027 1,520 Other financial losses (20,758 ) (10,394 ) (9,638 ) Total 18,434 8,505 (200,153 ) According to the agreement reached with Abengoa in the third quarter of 2016, Abengoa acknowledged that Atlantica Yield is the legal owner of the dividends declared on February 24, 2017 and retained from Abengoa amounting to $10.4 million. As a result, the Company recorded $10.4 million as Other financial income in accordance with the accounting treatment previously given to the ACBH dividend. Other financial losses for the year ended December 31, 2017 consist primarily of a loss resulting from the derecognition of the fair value assigned to ACBH preferred equity investment and recognition of the Abengoa Debt and Equity Instruments for $5.8 million (see Note 8). Residual items presented as Other financial losses are guarantees and letters of credit, wire transfers, other bank fees and other minor financial expenses. Other financial income consists primarily of $16.2 million income as a result of the termination of the currency swap agreement with Abengoa (see Note 9) and the profit resulting from the sale of the majority of the Abengoa Debt and Equity instruments for $6.5 million (see Note 8).

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2017
Earnings per share [Abstract]
Earnings per share	Note 22.- Earnings per share Basic earnings per share for the year 2017 has been calculated by dividing the profit/(loss) attributable to equity holders of the company by the number of shares outstanding. Diluted earnings per share equals basic earnings per share for the period presented. For the year ended December 31, Item 2017 2016 2015 Profit/(loss) from continuing operations attributable to Atlantica Yield Plc. (111,804 ) (4,855 ) (209,005 ) Profit/(loss) from discontinuing operations attributable to Atlantica Yield Plc. - - - Average number of ordinary shares outstanding (thousands) - basic and diluted 100,217 100,217 92,795 Earnings per share from continuing operations (US dollar per share) - basic and diluted (1.12 ) (0.05 ) (2.25 ) Earnings per share from discontinuing operations (US dollar per share) - basic and diluted - - - Earnings per share from profit/ (loss) for the period (US dollar per share) - basic and diluted (1.12 ) (0.05 ) (2.25 )

Other information

Other information	12 Months Ended
	Dec. 31, 2017
Other information [Abstract]
Other information	Note 23.- Other information 23.1 Restricted Net assets Certain of the consolidated entities are restricted from remitting certain funds to Atlantica Yield plc. as a result of a number of regulatory, contractual or statutory requirements. These restrictions are related to standard requirements to maintain debt service coverage ratios. In addition, some of the assets of the Company have forbearance in relation to cross defaults and change of ownership provisions with Abengoa, under certain conditions. Under the definition of the Securities and Exchange Commission Regulation S-X Rule 12-04, these are also considered restricted for the purposes of this calculation. At December 31, 2017, the accumulated amount of the temporary restrictions for the entire restricted term of these affiliates was $566 million. The Company performed a test on the restricted net assets of consolidated subsidiaries in accordance with Securities and Exchange Commission Regulation S-X Rule 12-04 and concluded the restricted net assets exceeded 25% of the consolidated net assets of the Company as of December 31, 2017. Therefore, the separate financial statements of Atlantica Yield, Plc. do have to be presented (see Appendix V (Schedule I) for details). 23.2 Subsequent events On February 27, 2018, the Board of Directors of the Company approved a dividend of $0.31 per share, which is expected to be paid on or about March 27, 2018.

Schedule I, Condensed Financial

Schedule I, Condensed Financial Statements	12 Months Ended
	Dec. 31, 2017
Schedule I, Condensed Financial Statements [Abstract]
Schedule I, Condensed Financial Statements	Appendix V (Schedule I) Condensed Financial Statements of Atlantica Yield plc Condensed statements of financial position of Atlantica Yield Plc. – Amounts in thousands of usd – As of December 31, 2017 2016 Assets Investment in affiliates 2,044,967 2,035,598 Loans to affiliates 647,911 704,916 Cash and cash equivalents 148,525 122,154 Other assets 3,704 23,936 Total assets 2,845,107 2,886,604 Liabilities and Equity Borrowings 386,616 412,839 Notes and bonds 256,468 255,362 Intercompany liabilities 103,796 54,687 Other Liabilities 11,168 10,296 Total Liabilities 758,048 733,184 Common Stock 10,022 10,022 Additional paid-in capital 1,981,881 1,981,881 Distributable reserves 42,410 116,375 Other reserves 181 13,879 Accumulated gains (losses)-net 52,565 31,263 Total shareholders’s equity 2,087,059 2,153,420 Total liabilities and equities 2,845,107 2,886,604 Condensed income statements of Atlantica Yield, Plc. – Amounts in thousands of usd – For the year ended December 31, 2017 2016 2015 Income from Services 123,944 114,653 65,170 Other financial income 17,419 8 194 Total income 141,363 114,661 65,364 Expenses Other operating expenses (21,173 ) (26,132 ) (10,005 ) Interest (46,292 ) (35,615 ) (27,783 ) Other financial expenses (21,333 ) (21,651 ) (246,982 ) Total expenses (88,798 ) (83,398 ) (284,770 ) Income/(Loss) before income taxes 52,565 31,263 (219,406 ) Income tax benefits/(expense) - - (209 ) Profit/(Loss) for the year 52,565 31,263 (219,615 ) Other comprehensive income statement of Atlantica Yield, Plc. – Amounts in thousands of usd – For the year ended December 31, 2017 2016 2015 Profit/(loss) for the year 52,565 31,263 (219,615 ) Items that may be subject to transfer to income statement Change in fair value of cash flow hedges (13,666 ) 7,213 3,683 Net income/(expenses) recognized directly in equity (13,666 ) 7,213 3,683 Cash flow hedges (32 ) 2,321 662 Transfer to income statement (32 ) 2,321 662 Other comprehensive income/(loss) for the year (13,698 ) 9,534 4,345 Total comprehensive income/(loss) for the year 38,867 40,797 (215,270 ) Condensed cash flow statements of Atlantica Yield, Plc. – Amounts in thousands of usd – For the year ended December 31, 2017 2016 2015 Cash Flow from operating activities 34,937 5,911 (15,943 ) Cash Flow—investing activities Decrease (increase) in investment and advance to affiliates 151,033 97,341 (939,503 ) Net decrease (increase) in other assets - - (157 ) Cash (used for)/provided by investing activities 151,033 97,341 (939,660 ) Cash Flow—financing activities Net increase/(decrease) in borrowings and other liabilities (64,754 ) - 310,462 Dividend paid to shareowner (94,845 ) (26,585 ) (128,859 ) Capital increase and other - - 664,120 Cash from financing activities (159,599 ) (26,585 ) 845,723 Increase (decrease) in cash and cash equivalents during the year 26,371 76,667 (109,880 ) Cash and cash equivalent at the beginning of the year 122,154 45,487 155,367 Cash and cash equivalent at the end of the year 148,525 122,154 45,487 Notes to the Condensed Financial Statements Schedule I has been provided pursuant to the requirements of Rule 12- 04(a) of Regulation S-X, of the US Securities and Exchange Commission (SEC) which require condensed financial information as to the financial position, change in financial position, results of operations of Atlantica Yield plc, other comprehensive income statement and cash flow statement as of the same dates and for the same periods for which audited consolidated financial statements have been presented when the restricted net assets of consolidated subsidiaries exceed 25 percent of consolidated net assets as of the end of the most recently completed fiscal year. Certain information and footnote disclosures normally included in financial statements prepared in accordance with International Financial Reporting Standards have been condensed or omitted. The footnote disclosures contain supplemental information only and, as such, these statements should be read in conjunction with the notes to the accompanying consolidated financial statements. Basis of Presentation. a) The presentation of Atlantica Yield plc stands alone condensed financial statement has been prepared using the same accounting policies as set out in the accompanying consolidated financial statements except that, the Company records its investment in subsidiaries under the cost method of accounting and that financial income from credits to companies in the group are recorded under Income from services, given that the company is a holding and this type of service is part of its primary activity. Such investments are presented on the statements of financial position as “Investment in and loans to affiliates” at cost less any identified impairment loss. b) As of December 31, 2017, 2016 and 2015 there were no material contingencies, significant provisions of long-term obligations, mandatory dividend or redemption requirements of redeemable stocks or guarantees of the Company, except for those which have been separately disclosed in the Consolidated Financial Statements, if any. c) For the year ended December 31, 2017, 2016 and 2015, cash dividend of $10,383 thousand, $29,737 thousand and $18,400 thousand were declared to the Company by its consolidated subsidiaries or associates, respectively. Reconciliation of the stand-alone to consolidated financial statements of Atlantica Yield Plc. For the year ended december 31, Profit/(Loss) Reconciliation 2017 2016 2015 Stand-alone—IFRS profit/(loss) for the period 52,565 31,263 (219,615 ) Additional profit/(loss) if subsidiaries had been accounted for using the equity method of accounting as opposed to cost method (164,369 ) (36,118 ) 10,610 Consolidated IFRS profit/(loss) for the period attributable to Atlantica Yield plc (111,804 ) (4,855 ) (209,005 ) Equity Reconciliation As of December 31, 2017 2016 2015 Stand-alone—IFRS shareholders equity 2,087,059 2,153,420 2,158,021 Additional shareholders equity if subsidiaries had been accounted for using the equity method of accounting as opposed to cost method (191,606 ) (194,309 ) (134,520 ) Consolidated IFRS shareholders equity 1,895,453 1,959,111 2,023,501

Significant accounting polici32

Significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2017
Significant accounting policies [Abstract]
Basis of preparation	2.1 Basis of preparation These consolidated financial statements are presented in accordance with the International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”). The Company entered into an agreement with Abengoa on June 13, 2014 (the “ROFO Agreement”), as amended and restated on December 9, 2014, that provides the Company with a right of first offer on any proposed sale, transfer or other disposition of any of Abengoa’s contracted renewable energy, efficient natural gas, electric transmission or water assets in operation and located in the United States, Canada, Mexico, Chile, Peru, Uruguay, Brazil, Colombia and the European Union, as well as four assets in selected countries in Africa, the Middle East and Asia. The Company elected to account for the assets acquisitions under the ROFO Agreement using the Predecessor values as long as Abengoa had control over the Company, given that these were transactions between entities under common control. Any difference between the consideration given and the aggregate book value of the assets and liabilities of the acquired entities as of the date of the transaction has been reflected as an adjustment to equity. Abengoa has no control over the Company since December 31, 2015. Therefore, any acquisition from Abengoa is accounted for in the consolidated accounts of Atlantica Yield since December 31, 2015, in accordance with IFRS 3, Business Combination. The consolidated financial statements are presented in U.S. dollars, which is the Company’s functional and presentation currency. Amounts included in these consolidated financial statements are all expressed in thousands of U.S. dollars, unless otherwise indicated. Application of new accounting standards a) Standards, interpretations and amendments effective from January 1, 2017 under IFRS-IASB, applied by the Company in the preparation of these consolidated financial statements: • IAS • IAS 12 (Amendment) ‘Recognition for Deferred Tax for Unrealized Losses’. Clarification of recognition of deferred tax assets for unrealized losses. • Annual Improvements to IFRSs 2014-2016 cycles. Amendments to IFRS 12. The applications of these amendments have not had any material impact on these consolidated financial statements except for the reconciliation of liabilities arising from financial activities that has been included in Note 14 and 15. b) Standards, interpretations and amendments published by the IASB that will be effective for periods beginning on or after January 1, 2018: • IFRS 9 ‘Financial Instruments’. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 9 (Amendments to IFRS 9): Prepayment Features with Negative Compensation. This Standard is applicable for annual periods beginning on or after January 1, 2019 under IFRS-IASB, earlier application is permitted. • IFRS 15 ‘Revenues from Contracts with Customers’. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 15 (Clarifications) ‘Revenues from Contracts with Customers’. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 16 ‘Leases’. This Standard is applicable for annual periods beginning on or after January 1, 2019 under IFRS-IASB, earlier application is permitted. • IFRS 17 ‘Insurance Contracts’. This Standard is applicable for annual periods beginning on or after January 1, 2021 under IFRS-IASB, earlier application is permitted. • IFRS 2 (Amendment) ‘Classification and Measurement of Share-based Payment Transactions’. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IFRS 4 (Amendment). Applying IFRS 9 ‘Financial Instruments’ with IFRS 4 ‘Insurance Contracts’. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IAS 40 (Amendment). Transfers of Investment Property. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • IAS 19 (Amendment). Amendments to IAS 19: Plan Amendment, Curtailment or Settlement. This amendment is mandatory for annual periods beginning on or after January 1, 2019 under IFRS-IASB, earlier application is permitted. • IAS 28 (Amendment). Long-term Interests in Associates and Joint Ventures. This amendment is mandatory for annual periods beginning on or after January 1, 2018 under IFRS-IASB, earlier application is permitted. • Annual Improvements to IFRSs 2014-2016 cycles. Other minor amendments and modifications different from the aforementioned on IFRS 12. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB. • Annual Improvements to IFRSs 2015-2017 cycles. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB. • IFRIC 22 Foreign Currency Transactions and Advance Consideration. This Standard is applicable for annual periods beginning on or after January 1, 2018 under IFRS-IASB. • IFRIC 23 Uncertainty over Income Tax Treatments. This Standard is applicable for annual periods beginning on or after January 1, 2019 under IFRS-IASB. • IFRS 10 and IAS 28. Parent disposes of (or contributes) its controlling interest in a subsidiary to an existing associate or joint venture. Effective date beginning on or after a date to be determined by the IASB. The application of these accounting standards is not expected to have a material impact on the consolidated financial statements of the Company. The analysis performed by the Company, relating to the impact of the new relevant accounting standards is as follows: IFRS 15 ‘Revenues from contracts with Customers’ In May 2014, the IASB (International Accounting Standards Board) published IFRS 15 “Recognition of Revenue from Contracts with Customers”. This Standard brings together all the applicable requirements and replaces the current standards for recognizing revenue: IAS 11 Construction Contracts, IAS 18 Revenue, IFRIC 13 Customer Loyalty Program, IFRIC 15 Agreements for the Construction of Real Estate, IFRIC 18 Transfers of Assets from Customers and SIC-31 Revenue—Barter Transactions Involving Advertising Services. The new requirements may lead to changes in the current revenue profile, since the Standard's main principle is that the Company must recognize its revenue in accordance with the transfer of goods or services to the customers in an amount which reflects the consideration that the Company expects to receive in exchange for these goods or services. The model laid out by the Standard is structured in five steps: · Step 1: Identifying the contract with the customer. · Step 2: Identifying the performance obligations. · Step 3: Determining the transaction price. · Step 4: Assigning the transaction price in the performance obligations identified in the contract. · Step 5: Recognition of revenue when (or as) the Company performs the performance obligations. Contracted concessional assets and price purchase agreements (PPAs) include fixed assets financed through project debt, related to service concession arrangements recorded in accordance with International Financial Reporting Interpretations Committee 12 (“IFRIC 12”), except for Palmucho, which is recorded in accordance with IAS 17 and PS10, PS20 and Seville PV, which are recorded as tangible assets in accordance with IAS 16. The infrastructures accounted for by the Company as concessions are related to the activities concerning electric transmission lines, solar electricity generation plants, cogeneration plants, wind farms and water plants. Currently, assets recorded in accordance with IFRIC 12 are classified as intangible assets or as financial assets, depending on the nature of the payment entitlements established in the contracts. According to IFRS 15, the Company should assess the goods and services promised in the contracts with the customers and shall identify as a performance obligation each promise to transfer to the customer a good or service (or a bundle of goods or services). In the case of contracts related to financial assets, the Company has identified two performance obligations (construction and operation of the asset). The contracts state that each service (construction and operation) has its own transaction price. For this reason, both performance obligations are separately identifiable in the context of the contract. The Company must allocate the total consideration to be received by the contract to each performance obligation. As mentioned above, the different services performed have been identified as two different performance obligations (construction and operation). Each performance obligation has its own transaction price stated in the contract. Such transaction prices are agreed in the contract by the parties in an orderly transaction, with no interrelation between both transaction prices and therefore correspond to the fair value of the goods and services provided in each case. As a result, for IFRS 15 purposes, the total transaction price will be allocated to each performance obligation in accordance with the two transaction prices stated within the contract, as they represent the respective fair values of the identified performance obligations. For the assets classified as intangible assets, the Company has identified the same performance obligations, (construction and operation), but in this case the consideration received by the Company for the construction services is a license. The grantor makes a non-cash payment for the construction services by giving the operator an intangible asset. When allocating fair value for IFRS 15 purposes, the Company will recognize as revenue for the first performance obligation the fair value of the construction services, and the amount corresponding to the sales of energy as the fair value of second performance obligation (operation). Additionally, in both cases, the services are satisfied over time. Therefore, the Company satisfies the performance obligations and recognizes revenue over time. The same conclusion applies to concessional assets that are classified as tangible assets or leases. IFRS 15 also incorporates specific criteria to determine which costs relating to a contract should be capitalized by distinguishing between incremental costs of obtaining a contract and costs associated with fulfilling a contract. No significant costs of obtaining a contract or compliance (other than those that are already capitalized) have been identified. As the current practice for revenue recognition is consistent with the analysis above under IFRS 15, the Company considers that the adoption of this standard will not have impact in the consolidated financial statements of the Company. Also, the Company has the intention to adopt IFRS 15 applying the full retrospective method to each prior reporting period presented, but without changes in the comparative reporting periods as the adoption of the standard has no effect in the financial statements. IFRS 9 ‘Financial Instruments’ IFRS 9 Financial Instruments issued on 24 July 2014 is the IASB's replacement of IAS 39 Financial Instruments: Recognition and Measurement. The standard addresses the classification, measurement and derecognition of financial assets and financial liabilities, introduces new rules for hedge accounting and a new impairment model for financial assets. The Company will be adopting the standard as of January 1, 2018, including the new requirements for hedge accounting (which application is voluntary for 2018). The Company will be adopting retrospectively without re-expressing comparative periods. The analysis performed by the Company is as follows: · Classification and measurement of financial instruments: a) Financial assets IFRS 9 classifies all financial assets that are currently in the scope of IAS 39 into two categories: amortized cost and fair value. Where assets are measured at fair value, gains and losses are either recognized entirely in profit or loss (fair value through profit or loss, “FVTPL”), or recognized in other comprehensive income (fair value through other comprehensive income, “FVTOCI”). The new guidance has no significant impact on the classification and measurement of the financial assets of the Company as the vast majority of financial assets (except for derivatives) are currently measured at amortized cost, and meet the conditions for classification at amortized cost under IFRS9. The Company has the intention of maintaining this classification. b) Financial liabilities: IFRS 9 does not change the basic accounting model for financial liabilities under IAS 39. Two measurement categories continue to exist: FVTPL and amortized cost. Financial liabilities held for trading are measured at FVTPL, and all other financial liabilities are measured at amortized cost unless the fair value option is applied. As a result, the Company concluded that there will be no significant impact on the consolidated financial statements. · The new impairment model requires the recognition of impairment provisions based on expected credit losses (“ECL”) rather than only incurred credit losses as is the case under IAS 39. The Company reviewed its portfolio of financial assets subject to the new model of impairment under the new methodology (using credit default swaps, rating from credit agencies and other external inputs in order to estimate the probability of default), and concluded that initial impact on the consolidated financial statements is not significant. · The accounting for certain modifications and exchanges of financial liabilities measured at amortized cost (e.g. bank loans and issued bonds) will change on the transition from IAS 39 to IFRS 9. This change arises from a clarification by the IASB in the Basis for Conclusions of IFRS 9. Under IFRS 9 it is now clear that there can be an effect in the income statement for modification and exchanges of financial liabilities that are considered “non-substantial” (when the net present value of the cash flows, including any fees paid net of any fees received, is lower than 10% different from the net present value of the remaining cash flows of the liability prior to the modification, both discounted at the original effective interest rate). The Company reviewed retrospectively these transactions and concluded that the impact is not significant. · IFRS 9 also introduces changes in hedge accounting. The hedge accounting requirements in IFRS 9 are optional and tend to facilitate the use of hedge accounting by preparers of financial statements. As a result, the Company reviewed its portfolio of derivatives and concluded that there will not be significant impact on its consolidated financial statements as a result of applying IFRS 9. · The new standard will require some new disclosures, in particular regarding hedge accounting, credit risk and ECLs that will be presented in future periods. IFRS 16 ‘Leases’ The IASB issued a new lease accounting standard, IFRS 16, in January 2016, which will require the recognition of lease contracts on the consolidated statement of financial position. IFRS 16 eliminates the classification of leases as either operating leases or finance leases for a lessee. Instead all leases are treated in a similar way to finance leases applying IAS 17. Leases are ‘capitalized’ by recognizing the present value of the lease payments and showing them either as lease assets (right-of-use of assets) or together with property, plant and equipment. If lease payments are made over time, a company also recognizes a financial liability representing its obligation to make future lease payments. In the income statement, IFRS 16 replaces the straight-line operating lease expense for those leases applying IAS 17, with a depreciation charge for the lease asset (included within operating expenses) and an interest expense on the lease liability (included within finance expenses). The Company performed its assessment of the impact on its consolidated financial statements. The most significant impact identified is that the Company will recognize new assets and liabilities for its existing operating leases of land rights, buildings, offices and equipment. The standard is effective for annual periods beginning on or after January 1, 2019, with earlier application permitted for entities that apply IFRS 15 at or before the date of initial application of IFRS 16. The Company decided to early adopt the standard as of January 1, 2018. An entity shall apply this standard using one of the following two methods: full retrospectively approach or a modified retrospective approach. The Company has chosen the latter and will account for assets as an amount equal to liability at the date of initial application. The Company estimates the impact on the consolidated statement of financial position as of January 1, 2018, is not significant (less than 1% of total assets).
Principles to include and record companies in the consolidated financial statements	2.2. Principles to include and record companies in the consolidated financial statements Companies included in these consolidated financial statements are accounted for as subsidiaries as long as Atlantica Yield has had control over them and are accounted for as investments under the equity method as long as Atlantica Yield has had significant influence over them, in the periods presented. a) Controlled entities Control is achieved when the Company: · Has power over the investee; · Is exposed, or has rights, to variable returns from its involvement with the investee; and · Has the ability to use its power to affect its returns. The Company reassesses whether or not it controls an investee when facts and circumstances indicate that there are changes to one or more of the three elements of control listed above. The Company uses the acquisition method to account for business combinations of companies controlled by a third party. According to this method, identifiable assets acquired and liabilities and contingent liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. Any contingent consideration is recognized at fair value at the acquisition date and subsequent changes in its fair value are recognized in accordance with IAS 39 either in profit or loss or as a change to other comprehensive income. Acquisition related costs are expensed as incurred. The Company recognizes any non-controlling interest in the acquiree either at fair value or at the non-controlling interest’s proportionate share of the acquirer’s net assets on an acquisition by acquisition basis. Acquisitions of businesses from Abengoa were until December 31, 2015, not considered business combinations, as Atlantica Yield was a subsidiary controlled by Abengoa. The assets acquired constituted an acquisition under common control by Abengoa and accordingly, were recorded using Abengoa’s historical basis in the assets and liabilities of the Predecessor. Abengoa has no control over the Company since December 31, 2015. Therefore, any purchase from Abengoa is accounted for in the consolidated accounts of Atlantica Yield since December 31, 2015, in accordance with IFRS 3, Business Combination. All assets and liabilities between entities of the group, equity, income, expenses, and cash flows relating to transactions between entities of the group are eliminated in full. b) Investments accounted for under the equity method An associate is an entity over which the Company has significant influence. Significant influence is the power to participate in the financial and operating policy decisions of the investee but is not control or joint control over those policies. The results and assets and liabilities of associates are incorporated in these financial statements using the equity method of accounting. Under the equity method, an investment in an associate is initially recognized in the statement of financial position at cost and adjusted thereafter to recognize the Company share of the profit or loss and other comprehensive income of the associate. Controlled entities and associates included in these financial statements as of December 31, 2017 and 2016 are set out in appendices.
Contracted concessional assets and price purchase agreements	2.3. Contracted concessional assets and price purchase agreements Contracted concessional assets and price purchase agreements (PPAs) include fixed assets financed through project debt, related to service concession arrangements recorded in accordance with IFRIC 12, except for Palmucho, which is recorded in accordance with IAS 17 and PS10, PS20 and Seville PV, which are recorded as tangible assets in accordance with IAS 16. The infrastructures accounted for by the Company as concessions are related to the activities concerning electric transmission lines, solar electricity generation plants, cogeneration plants, wind farms and water plants. The useful life of these assets is approximately the same as the length of the concession arrangement. The infrastructure used in a concession can be classified as an intangible asset or a financial asset, depending on the nature of the payment entitlements established in the agreement. The application of IFRIC 12 requires extensive judgment in relation with, among other factors, (i) the identification of certain infrastructures and contractual agreements in the scope of IFRIC 12, (ii) the understanding of the nature of the payments in order to determine the classification of the infrastructure as a financial asset or as an intangible asset and (iii) the timing and recognition of the revenue from construction and concessionary activity. Under the terms of contractual arrangements within the scope of this interpretation, the operator shall recognize and measure revenue in accordance with IAS 11 and 18 for the services it performs. If the operator performs more than one service (i.e. construction or upgrade services and operation services) under a single contract or arrangement, consideration received or receivable shall be allocated by reference to the relative fair values of the services delivered, when the amounts are separately identifiable. a) Intangible asset The Company recognizes an intangible asset to the extent that it receives a right to charge final customers for the use of the infrastructure. This intangible asset is subject to the provisions of IAS 38 and is amortized linearly, taking into account the estimated period of commercial operation of the infrastructure which coincides with the concession period. Once the infrastructure is in operation, the treatment of income and expenses is as follows: · Revenues from the updated annual revenue for the contracted concession, as well as operations and maintenance services are recognized in each period according to IAS 18 “Revenue”. · Operating and maintenance costs and general overheads and administrative costs are recorded in accordance with the nature of the cost incurred (amount due) in each period. · Financing costs are expensed as incurred. b) Financial asset The Company recognizes a financial asset when demand risk is assumed by the grantor, to the extent that the concession holder has an unconditional right to receive payments for the asset. This asset is recognized at the fair value of the construction services provided, considering upgrade services in accordance with IAS 11, if any. The financial asset is subsequently recorded at amortized cost calculated according to the effective interest method. Revenue from operations and maintenance services is recognized in each period according to IAS 18 “Revenue”. The remuneration of managing and operating the asset resulting from the valuation at amortized cost is also recorded in revenue. Financing costs are expensed as incurred. c) Property, plant and equipment Property, plant and equipment includes property, plant and equipment of companies or project companies. Property, plant and equipment is measured at historical cost, including all expenses directly attributable to the acquisition, less depreciation and impairment losses, with the exception of land, which is presented net of any impairment losses. Once the infrastructure is in operation, the treatment of income and expenses is the same as the one described above for intangible asset.
Borrowing costs	2.4. Borrowing costs Interest costs incurred in the construction of any qualifying asset are capitalized over the period required to complete and prepare the asset for its intended use. A qualifying asset is an asset that necessarily takes a substantial period of time to get ready for its internal use or sale, which is considered to be more than one year. Remaining borrowing costs are expensed in the period in which they are incurred.
Asset impairment	2.5 Asset impairment Atlantica Yield reviews its contracted concessional assets to identify any indicators of impairment at least annually. The recoverable amount of an asset is the higher of its fair value less costs to sell and its value in use, defined as the present value of the estimated future cash flows to be generated by the asset. In the event that the asset does not generate cash flows independently of other assets, the Company calculates the recoverable amount of the Cash Generating Unit (‘CGU’) to which the asset belongs. When the carrying amount of the CGU to which these assets belong is higher than its recoverable amount, the assets are impaired. Assumptions used to calculate value in use include a discount rate, growth rate and projections considering real data based in the contracts terms and projected changes in both selling prices and costs. The discount rate is estimated by Management, to reflect both changes in the value of money over time and the risks associated with the specific CGU. For contracted concessional assets, with a defined useful life and with a specific financial structure, cash flow projections until the end of the project are considered and no terminal value is assumed. Contracted concessional assets have a contractual structure that permits the Company to estimate quite accurately the costs of the project (both in the construction and in the operations periods) and revenue during the life of the project. Projections take into account real data based on the contract terms and fundamental assumptions based on specific reports prepared by experts, assumptions on demand and assumptions on production. Additionally, assumptions on macro-economic conditions are taken into account, such as inflation rates, future interest rates, etc. and sensitivity analyses are performed over all major assumptions which can have a significant impact in the value of the asset. Cash flow projections of CGUs are calculated in the functional currency of those CGUs and are discounted using rates that take into consideration the risk corresponding to each specific country and currency. Taking into account that in most CGUs the specific financial structure is linked to the financial structure of the projects that are part of those CGUs, the discount rate used to calculate the present value of cash-flow projections is based on the weighted average cost of capital (WACC) for the type of asset, adjusted, if necessary, in accordance with the business of the specific activity and with the risk associated with the country where the project is performed. In any case, sensitivity analyses are performed, especially in relation with the discount rate used and fair value changes in the main business variables, in order to ensure that possible changes in the estimates of these items do not impact the possible recovery of recognized assets. Accordingly, the following table provides a summary of the discount rates used (WACC) and growth rates to calculate the recoverable amount for CGUs with the operating segment to which it pertains: Operating segment Discount rate Growth rate EMEA 4% - 6 % 0 % North America 4% - 6 % 0 % South America 5% - 7 % 0 % In the event that the recoverable amount of an asset is lower than its carrying amount, an impairment charge for the difference would be recorded in the income statement under the item “Depreciation, amortization and impairment charges”. Pursuant to IAS 36, an impairment loss is recognized if the carrying amount of these assets exceeds the present value of future cash flows discounted at the initial effective interest rate.
Loans and accounts receivable	2.6 Loans and accounts receivable Loans and accounts receivable are non-derivative financial assets with fixed or determinable payments, not listed on an active market. In accordance with IFRIC 12, certain assets under concessions qualify as financial assets and are recorded as is described in Note 2.3. Pursuant to IAS 36, an impairment loss is recognized if the carrying amount of these assets exceeds the present value of future cash flows discounted at the initial effective interest rate. Loans and accounts receivable are initially recognized at fair value plus transaction costs and are subsequently measured at amortized cost in accordance with the effective interest rate method. Interest calculated using the effective interest rate method is recognized under other financial income within financial income.
Derivative financial instruments and hedging activities	2.7. Derivative financial instruments and hedging activities Derivatives are recorded at fair value. The Company applies hedge accounting to all hedging derivatives that qualify to be accounted for as hedges under IFRS-IASB. When hedge accounting is applied, hedging strategy and risk management objectives are documented at inception, as well as the relationship between hedging instruments and hedged items. Effectiveness of the hedging relationship needs to be assessed on an ongoing basis. Effectiveness tests are performed prospectively and retrospectively at inception and at each reporting date, following the dollar offset method or the regression method, depending on the type of derivatives and the type of tests performed. Atlantica Yield applies cash flow hedging. Under this method, the effective portion of changes in fair value of derivatives designated as cash flow hedges are recorded temporarily in equity and are subsequently reclassified from equity to profit or loss in the same period or periods during which the hedged item affects profit or loss. Any ineffective portion of the hedged transaction is recorded in the consolidated income statement as it occurs. When interest rate options are designated as hedging instruments, the intrinsic value and time value of the financial hedge instrument are separated. Changes in intrinsic value which are highly effective are recorded in equity and subsequently reclassified from equity to profit or loss in the same period or periods during which the hedged item affects profit or loss. Changes in time value are recorded as financial income or expense, together with any ineffectiveness. When the hedging instrument matures or is sold, or when it no longer meets the requirements to apply hedge accounting, accumulated gains and losses recorded in equity remain as such until the forecast transaction is ultimately recognized in the income statement. However, if it becomes unlikely that the forecast transaction will actually take place, the accumulated gains and losses in equity are recognized immediately in the income statement.
Fair value estimates	2.8. Fair value estimates Financial instruments measured at fair value are presented in accordance with the following level classification based on the nature of the inputs used for the calculation of fair value: · Level 1: Inputs are quoted prices in active markets for identical assets or liabilities. · Level 2: Fair value is measured based on inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. as prices) or indirectly (i.e. derived from prices). · Level 3: Fair value is measured based on unobservable inputs for the asset or liability. In the event that prices cannot be observed, the management shall make its best estimate of the price that the market would otherwise establish based on proprietary internal models which, in the majority of cases, use data based on observable market parameters as significant inputs (Level 2) but occasionally use market data that is not observed as significant inputs (Level 3). Different techniques can be used to make this estimate, including extrapolation of observable market data. The best indication of the initial fair value of a financial instrument is the price of the transaction, except when the value of the instrument can be obtained from other transactions carried out in the market with the same or similar instruments, or valued using a valuation technique in which the variables used only include observable market data, mainly interest rates. Differences between the transaction price and the fair value based on valuation techniques that use data that is not observed in the market, are not initially recognized in the income statement. Atlantica Yield derivatives correspond primarily to the interest rate swaps designated as cash flow hedges, which are classified as Level 2: Description of the valuation method Interest rate swap valuations are made by valuing the swap part of the contract and valuing the credit risk. The methodology used by the market and applied by Atlantica Yield to value interest rate swaps is to discount the expected future cash flows according to the parameters of the contract. Variable interest rates, which are needed to estimate future cash flows, are calculated using the curve for the corresponding currency and extracting the implicit rates for each of the reference dates in the contract. These estimated flows are discounted with the swap zero curve for the reference period of the contract. The effect of the credit risk on the valuation of the interest rate swaps depends on the future settlement. If the settlement is favorable for the Company, the counterparty credit spread will be incorporated to quantify the probability of default at maturity. If the expected settlement is negative for the Company, its own credit risk will be applied to the final settlement. Classic models for valuing interest rate swaps use deterministic valuation of the future of variable rates, based on future outlooks. When quantifying credit risk, this model is limited by considering only the risk for the current paying party, ignoring the fact that the derivative could change sign at maturity. A payer and receiver swaption model is proposed for these cases. This enables the associated risk in each swap position to be reflected. Thus, the model shows each agent’s exposure, on each payment date, as the value of entering into the ‘tail’ of the swap, i.e. the live part of the swap. Variables (Inputs) Interest rate derivative valuation models use the corresponding interest rate curves for the relevant currency and underlying reference in order to estimate the future cash flows and to discount them. Market prices for deposits, futures contracts and interest rate swaps are used to construct these curves. Interest rate options (caps and floors) also use the volatility of the reference interest rate curve. To estimate the credit risk of the counterparty, the credit default swap (CDS) spreads curve is obtained in the market for important individual issuers. For less liquid issuers, the spreads curve is estimated using comparable CDSs or based on the country curve. To estimate proprietary credit risk, prices of debt issues in the market and CDSs for the sector and geographic location are used. The fair value of the financial instruments that results from the aforementioned internal models takes into account, among other factors, the terms and conditions of the contracts and observable market data, such as interest rates, credit risk and volatility. The valuation models do not include significant levels of subjectivity, since these methodologies can be adjusted and calibrated, as appropriate, using the internal calculation of fair value and subsequently compared to the corresponding actively traded price. However, valuation adjustments may be necessary when the listed market prices are not available for comparison purposes.
Clients and other receivables	2.9. Clients and other receivables Clients and other receivables are amounts due from customers for sales in the normal course of business. They are recognized initially at fair value and subsequently measured at amortized cost using the effective interest rate method, less allowance for doubtful accounts. Trade receivables due in less than one year are carried at their face value at both initial recognition and subsequent measurement, provided that the effect of not discounting flows is not significant. An allowance for doubtful accounts is recorded when there is objective evidence that the Company will not be able to recover all amounts due as per the original terms of the receivables.
Cash and cash equivalents	2.10. Cash and cash equivalents Cash and cash equivalents include cash in hand, cash in bank and other highly-liquid current investments with an original maturity of three months or less which are held for the purpose of meeting short-term cash commitments.
Grants	2.11. Grants Grants are recognized at fair value when it is considered that there is a reasonable assurance that the grant will be received and that the necessary qualifying conditions, as agreed with the entity assigning the grant, will be adequately complied with. Grants are recorded as liabilities in the consolidated statement of financial position and are recognized in “Other operating income” in the consolidated income statement based on the period necessary to match them with the costs they intend to compensate. In addition, as described in Note 2.12 below, grants correspond also to loans with interest rates below market rates, for the initial difference between the fair value of the loan and the proceeds received.
Loans and borrowings	2.12. Loans and borrowings Loans and borrowings are initially recognized at fair value, net of transaction costs incurred. Borrowings are subsequently measured at amortized cost and any difference between the proceeds initially received (net of transaction costs incurred in obtaining such proceeds) and the repayment value is recognized in the consolidated income statement over the duration of the borrowing using the effective interest rate method. Loans with interest rates below market rates are initially recognized at fair value in liabilities and the difference between proceeds received from the loan and its fair value is initially recorded within “Grants and Other liabilities” in the consolidated statement of financial position, and subsequently recorded in “Other operating income” in the consolidated income statement when the costs financed with the loan are expensed.
Bonds and notes	2.13. Bonds and notes The Company initially recognizes ordinary notes at fair value, net of issuance costs incurred. Subsequently, notes are measured at amortized cost until settlement upon maturity. Any other difference between the proceeds obtained (net of transaction costs) and the redemption value is recognized in the consolidated income statement over the term of the debt using the effective interest rate method.
Income taxes	2.14. Income taxes Current income tax expense is calculated on the basis of the tax laws in force as of the date of the consolidated statement of financial position in the countries in which the subsidiaries and associates operate and generate taxable income. Deferred income tax is calculated in accordance with the liability method, based upon the temporary differences arising between the carrying amount of assets and liabilities and their tax base. Deferred income tax is determined using tax rates and regulations which are expected to apply at the time when the deferred tax is realized. Deferred tax assets are recognized only when it is probable that sufficient future taxable profit will be available to use deferred tax assets.
Trade payables and other liabilities	2.15. Trade payables and other liabilities Trade payables are obligations arising from purchases of goods and services in the ordinary course of business and are recognized initially at fair value and are subsequently measured at their amortized cost using the effective interest method. Other liabilities are obligations not arising in the normal course of business and which are not treated as financing transactions. Advances received from customers are recognized as “Trade payables and other current liabilities”.
Foreign currency transactions	2.16. Foreign currency transactions The consolidated financial statements are presented in U.S. dollars, which is Atlantica Yield functional and reporting currency. Financial statements of each subsidiary within the Company are measured in the currency of the principal economic environment in which the subsidiary operates, which is the subsidiary’s functional currency. Transactions denominated in a currency different from the subsidiary’s functional currency are translated into the subsidiary’s functional currency applying the exchange rates in force at the time of the transactions. Foreign currency gains and losses that result from the settlement of these transactions and the translation of monetary assets and liabilities denominated in foreign currency at the year-end rates are recognized in the consolidated income statement, unless they are deferred in equity, as occurs with cash flow hedges and net investment in foreign operations hedges. Assets and liabilities of subsidiaries with a functional currency different from the Company’s reporting currency are translated to U.S. dollars at the exchange rate in force at the closing date of the financial statements. Income and expenses are translated into U.S. dollars using the average annual exchange rate, which does not differ significantly from using the exchange rates of the dates of each transaction. The difference between equity translated at the historical exchange rate and the net financial position that results from translating the assets and liabilities at the closing rate is recorded in equity under the heading “Accumulated currency translation differences”. Results of companies carried under the equity method are translated at the average annual exchange rate.
Equity	2.17. Equity The Company has recyclable balances in its equity, corresponding mainly to hedge reserves and translation differences arising from currency conversion in the preparation of these consolidated financial statements. These balances have been presented separately in Equity. Non-controlling interest represents interest from other partners in entities included in these consolidated financial statements which are not fully owned by Atlantica Yield as of the dates presented. Parent company reserves together with the Share capital represent the Parent’s net investment in the entities included in these consolidated financial statements.
Provisions and contingencies	2.18. Provisions and contingencies Provisions are recognized when: · there is a present obligation, either legal or constructive, as a result of past events; · it is more likely than not that there will be a future outflow of resources to settle the obligation; and · the amount has been reliably estimated. Provisions are initially measured at the present value of the expected outflows required to settle the obligation and subsequently valued at amortized cost following the effective interest method. The balance of Provisions disclosed in the Notes reflects management’s best estimate of the potential exposure as of the date of preparation of the consolidated financial statements. Contingent liabilities are possible obligations, existing obligations with low probability of a future outflow of economic resources and existing obligations where the future outflow cannot be reliably estimated. Contingences are not recognized in the consolidated statements of financial position unless they have been acquired in a business combination. Some companies included in the group have dismantling provisions, which are intended to cover future expenditures related to the dismantlement of the plants and it will be likely to be settled with an outflow of resources in the long term (over 5 years). Such provisions are accrued when the obligation for dismantling, removing and restoring the site on which the plant is located, is incurred, which is usually during the construction period. The provision is measured in accordance with IAS 37, “Provisions, Contingent Liabilities and Contingent Assets” and is recorded as a liability under the heading “Grants and other liabilities” of the Financial Statements, and as part of the cost of the plant under the heading “Contracted concessional assets.”
Use of estimates	2.19. Use of estimates Some of the accounting policies applied require the application of significant judgment by management to select the appropriate assumptions to determine these estimates. These assumptions and estimates are based on the historical experience, advice from experienced consultants, forecasts and other circumstances and expectations as of the close of the financial period. The assessment is considered in relation to the global economic situation of the industries and regions where the Company operates, taking into account future development of the businesses of the Company. By their nature, these judgments are subject to an inherent degree of uncertainty; therefore, actual results could materially differ from the estimates and assumptions used. In such cases, the carrying values of assets and liabilities are adjusted. The most critical accounting policies, which reflect significant management estimates and judgment to determine amounts in these consolidated financial statements, are as follows: · Contracted concessional agreements and PPAs. · Impairment of intangible assets and property, plant and equipment. · Assessment of control. · Derivative financial instruments and fair value estimates. · Income taxes and recoverable amount of deferred tax assets. As of the date of preparation of these consolidated financial statements, no relevant changes in the estimates made are anticipated and, therefore, no significant changes in the value of the assets and liabilities recognized at December 31, 2017, are expected. Although these estimates and assumptions are being made using all available facts and circumstances, it is possible that future events may require management to amend such estimates and assumptions in future periods. Changes in accounting estimates are recognized prospectively, in accordance with IAS 8, in the consolidated income statement of the year in which the change occurs.

Nature of the business (Tables)

Nature of the business (Tables)	12 Months Ended
	Dec. 31, 2017
Nature of the business [Abstract]
Overview of concessional assets	The following table provides an overview of the concessional assets the Company owned as of December 31, 2017 (excluding the 12.5% interest in the transmission line in the U.S. acquired in February 2017): Assets Type Ownership Location Currency (8) Capacity (Gross) Counterparty Credit Ratings (9) COD* Contract Years Left (12) Solana Renewable (Solar) 100% Class B (1) Arizona (USA) USD 280 MW A-/A3/A- 4Q 2013 26 Mojave Renewable (Solar) 100% California (USA) USD 280 MW A-/A3/A- 4Q 2014 22 Solaben 2 & 3 Renewable (Solar) 70% (2) Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2012 & 2Q 2012 20&19 Solacor 1 & 2 Renewable (Solar) 87% (3) Spain Euro 2x50 MW BBB+/Baa2/A- 1Q 2012 & 1Q 2012 19 PS10/PS20 Renewable (Solar) 100% Spain Euro 31 MW BBB+/Baa2/A- 1Q 2007 & 2Q 2009 14&16 Helioenergy 1 & 2 Renewable (Solar) 100% Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2011& 4Q 2011 19 Helios 1 & 2 Renewable (Solar) 100% Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2012& 3Q 2012 20 Solnova 1, 3 & 4 Renewable (Solar) 100% Spain Euro 3x50 MW BBB+/Baa2/A- 2Q 2010 & 2Q 2010& 3Q 2010 17&17&18 Solaben 1 & 6 Renewable (Solar) 100% Spain Euro 2x50 MW BBB+/Baa2/A- 3Q 2013 21 Kaxu Renewable (Solar) 51% (4) South Africa Rand 100 MW BB/Baa3/BB+ (10) 1Q 2015 17 Palmatir Renewable (Wind) 100% Uruguay USD 50 MW BBB/Baa2/BBB- (11) 2Q 2014 16 Cadonal Renewable (Wind) 100% Uruguay USD 50 MW BBB/Baa2/BBB- (11) 4Q 2014 17 ACT Efficient natural gas 100% Mexico USD 300 MW BBB+/A3/ BBB+ 2Q 2013 15 ATN Transmission line 100% Peru USD 362 miles BBB+/A3/BBB+ 1Q 2011 23 ATS Transmission line 100% Peru USD 569 miles BBB+/A3/BBB+ 1Q 2014 26 ATN 2 Transmission line 100% Peru USD 81 miles Not rated 2Q 2015 15 Quadra 1 Transmission line 100% Chile USD 49 miles Not rated 2Q 2014 17 Quadra 2 Transmission line 100% Chile USD 32 miles Not rated 1Q 2014 17 Palmucho Transmission line 100% Chile USD 6 miles BBB+/Baa2/BBB+ 4Q 2007 20 Skikda Water 34.2% (5) Algeria USD 3.5 M ft3/day Not rated 1Q 2009 16 Honaine Water 25.5% (6) Algeria USD 7 M ft3/ day Not rated 3Q 2012 20 Seville PV Renewable (Solar) 80% (7) Spain Euro 1 MW BBB+/Baa2/A- 3Q 2006 18 (1) On September 30, 2013, Liberty Interactive Corporation invested $300,000 thousand in Class A membership interests in exchange for a share of the dividends and taxable loss generated by Solana. As a result of the agreement, Liberty Interactive Corporation will receive between 54.06% and 61.20% of both dividends and taxable loss generated, additional amounts until the date Liberty reaches a certain rate of return or the “Flip Date”, and 22.60% of both dividends and taxable loss generated thereafter. (2) Itochu Corporation, a Japanese trading company, holds 30% of the shares in each of Solaben 2 and Solaben 3. (3) JGC, a Japanese engineering company, holds 13% of the shares in each of Solacor 1 and Solacor 2. (4) Kaxu is owned by the Company (51%), Industrial Development Corporation of South Africa (29%) and Kaxu Community Trust (20%). (5) Algerian Energy Company, SPA owns 49% of Skikda and Valoriza Agua, S.L. owns the remaining 16.83%. (6) Algerian Energy Company, SPA owns 49% of Honaine and Valoriza Agua, S.L. owns the remaining 25.5%. (7) Instituto para la Diversificación y Ahorro de la Energía (“Idae”), a Spanish state owned company, holds 20% of the shares in Seville PV. (8) Certain contracts denominated in U.S. dollars are payable in local currency. (9) Reflects the counterparty’s credit ratings issued by Standard & Poor’s Ratings Services, or S&P, Moody’s Investors Service Inc., or Moody’s, and Fitch Ratings Ltd, or Fitch. (10) Refers to the credit rating of the Republic of South Africa. The offtaker is Eskom, which is a state-owned utility company in South Africa. (11) Refers to the credit rating of Uruguay, as UTE (Administración Nacional de Usinas y Transmisoras Eléctricas) is unrated. (12) As of December 31, 2017. * Commercial Operation Date (“COD”).

Significant accounting polici34

Significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2017
Significant accounting policies [Abstract]
Discount rates and growth rates used to calculated recoverable amount for CGUs by segment	Accordingly, the following table provides a summary of the discount rates used (WACC) and growth rates to calculate the recoverable amount for CGUs with the operating segment to which it pertains: Operating segment Discount rate Growth rate EMEA 4% - 6 % 0 % North America 4% - 6 % 0 % South America 5% - 7 % 0 %

Financial information by segm35

Financial information by segment (Tables)	12 Months Ended
	Dec. 31, 2017
Financial information by segment [Abstract]
Revenues and Further Adjusted EBITDA, assets and liabilities by operating segments and business sectors	a) The following tables show Revenues and Further Adjusted EBITDA by operating segments and business sectors for the years 2017, 2016 and 2015: Revenue Further Adjusted EBITDA For the year ended December 31, For the year ended December 31, Geography 2017 2016 2015 2017 2016 2015 North America $ 332,705 $ 337,061 $ 328,139 $ 282,328 $ 284,691 $ 279,559 South America 120,797 118,764 112,480 108,766 124,599 110,905 EMEA 554,879 515,972 350,262 388,216 354,020 233,754 Total $ 1,008,381 $ 971,797 $ 790,881 $ 779,310 $ 763,310 $ 624,218 Revenue Further Adjusted EBITDA For the year ended December 31, For the year ended December 31, Business sectors 2017 2016 2015 2017 2016 2015 Renewable energy $ 767,226 $ 724,325 $ 543,012 $ 569,193 $ 538,427 $ 413,933 Efficient natural gas 119,784 128,046 138,717 106,140 106,492 107,671 Electric transmission lines 95,096 95,137 86,393 87,695 104,795 89,047 Water 26,275 24,288 22,759 16,282 13,596 13,567 Total $ 1,008,381 $ 971,797 $ 790,881 $ 779,310 $ 763,310 $ 624,218 The reconciliation of segment Further Adjusted EBITDA with the profit/(loss) attributable to the parent company is as follows: For the year ended December 31, 2017 2016 2015 Loss attributable to the Company $ (111,804 ) $ (4,855 ) $ (209,005 ) Profit attributable to non-controlling interests 6,917 6,522 10,819 Income tax 119,837 1,666 23,790 Share of profits/(losses) of associates (5,351 ) (6,646 ) (7,844 ) Dividend from exchangeable preferred equity investment in ACBH (Note 21) 10,383 27,948 18,400 Financial expense, net 448,368 405,750 526,758 Depreciation, amortization, and impairment charges 310,960 332,925 261,301 Total segment Further Adjusted EBITDA $ 779,310 $ 763,310 $ 624,219
Assets and liabilities by geography	b) The assets and liabilities by operating segments (and business sector) at the end of 2017 and 2016 are as follows: Assets and liabilities by geography as of December 31, 2017: North America South America EMEA Balance as of December 31, 2017 Assets allocated Contracted concessional assets 3,770,169 1,100,778 4,213,323 9,084,270 Investments carried under the equity method - - 55,784 55,784 Current financial investments 116,451 59,831 31,263 207,545 Cash and cash equivalents (project companies) 149,236 42,548 329,078 520,862 Subtotal allocated 4,035,856 1,203,157 4,629,448 9,868,461 Unallocated assets Other non-current assets 210,378 Other current assets (including cash and cash equivalents at holding company level) 413,500 Subtotal unallocated 623,878 Total assets 10,492,339 North America South America EMEA Balance as of December 31, 2017 Liabilities allocated Long-term and short-term project debt 1,821,102 876,063 2,778,043 5,475,208 Grants and other liabilities 1,593,048 810 42,202 1,636,060 Subtotal allocated 3,414,150 876,873 2,820,245 7,111,268 Unallocated liabilities Long-term and short-term corporate debt 643,083 Other non-current liabilities 657,345 Other current liabilities 185,190 Subtotal unallocated 1,485,618 Total liabilities 8,596,886 Equity unallocated 1,895,453 Total liabilities and equity unallocated 3,381,071 Total liabilities and equity 10,492,339 Assets and liabilities by geography as of December 31, 2016: North America South America EMEA Balance as of December 31, 2016 Assets allocated Contracted concessional assets 3,920,106 1,144,712 3,859,454 8,924,272 Investments carried under the equity method - - 55,009 55,009 Current financial investments 136,665 62,215 29,158 228,038 Cash and cash equivalents (project companies) 185,970 40,015 246,671 472,656 Subtotal allocated 4,242,741 1,246,942 4,190,291 9,679,975 Unallocated assets Other non-current assets 272,664 Other current assets (including cash and cash equivalents at holding company level) 345,160 Subtotal unallocated 617,824 Total assets 10,297,799 North America South America EMEA Balance as of December 31, 2016 Liabilities allocated Long-term and short-term project debt 1,870,861 895,316 2,564,290 5,330,467 Grants and other liabilities 1,575,303 1,512 35,230 1,612,045 Subtotal allocated 3,446,164 896,828 2,599,520 6,942,512 Unallocated liabilities Long-term and short-term corporate debt 668,201 Other non-current liabilities 546,053 Other current liabilities 181,922 Subtotal unallocated 1,396,176 Total liabilities 8,338,688 Equity unallocated 1,959,111 Total liabilities and equity unallocated 3,355,287 Total liabilities and equity 10,297,799
Assets and liabilities by business sectors	Assets and liabilities by business sectors as of December 31, 2017: Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2017 Assets allocated Contracted concessional assets 7,436,362 660,387 897,269 90,252 9,084,270 Investments carried under the equity method 12,419 - - 43,365 55,784 Current financial investments 17,249 116,430 59,289 14,577 207,545 Cash and cash equivalents (project companies) 452,792 39,064 15,325 13,681 520,862 Subtotal allocated 7,918,822 815,881 971,883 161,875 9,868,461 Unallocated assets Other non-current assets 210,378 Other current assets (including cash and cash equivalents at holding company level) 413,500 Subtotal unallocated 623,878 Total assets 10,492,339 Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2017 Liabilities allocated Long-term and short-term project debt 4,162,596 579,173 698,346 35,093 5,475,208 Grants and other liabilities 1,635,508 552 - - 1,636,060 Subtotal allocated 5,798,104 579,725 698,346 35,093 7,111,268 Unallocated liabilities Long-term and short-term corporate debt 643,083 Other non-current liabilities 657,345 Other current liabilities 185,190 Subtotal unallocated 1,485,618 Total liabilities 8,596,886 Equity unallocated 1,895,453 Total liabilities and equity unallocated 3,381,071 Total liabilities and equity 10,492,339 Assets and liabilities by business sectors as of December 31, 2016: Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2016 Assets allocated Contracted concessional assets 7,255,308 646,927 929,005 93,032 8,924,272 Investments carried under the equity method 12,953 - - 42,056 55,009 Current financial investments 13,661 136,644 62,215 15,518 228,038 Cash and cash equivalents (project companies) 420,215 30,295 11,357 10,789 472,656 Subtotal allocated 7,702,137 813,866 1,002,577 161,395 9,679,975 Unallocated assets Other non-current assets 272,664 Other current assets (including cash and cash equivalents at holding company level) 345,160 Subtotal unallocated 617,824 Total assets 10,297,799 Renewable energy Efficient natural gas Electric transmission lines Water Balance as of December 31, 2016 Liabilities allocated Long-term and short-term project debt 3,979,096 598,256 711,517 41,598 5,330,467 Grants and other liabilities 1,611,067 239 739 - 1,612,045 Subtotal allocated 5,590,163 598,495 712,256 41,598 6,942,512 Unallocated liabilities Long-term and short-term corporate debt 668,201 Other non-current liabilities 546,053 Other current liabilities 181,922 Subtotal unallocated 1,396,176 Total liabilities 8,338,688 Equity unallocated 1,959,111 Total liabilities and equity unallocated 3,355,287 Total liabilities and equity 10,297,799
Depreciation, amortization and impairment charges recognized	c) The amount of depreciation, amortization and impairment charges recognized for the years ended December 31, 2017, 2016 and 2015 are as follows: For the year ended December 31, Depreciation, amortization and impairment by geography 2017 2016 2015 North America (123,726 ) (129,478 ) (129,091 ) South America (40,880 ) (62,387 ) (41,274 ) EMEA (146,354 ) (141,060 ) (90,936 ) Total (310,960 ) (332,925 ) (261,301 ) For the year ended December 31, Depreciation, amortization and impairment by business sectors 2017 2016 2015 Renewable energy (282,376 ) (304,235 ) (232,699 ) Electric transmission lines (28,584 ) (28,690 ) (28,602 ) Total (310,960 ) (332,925 ) (261,301 )

Contracted concessional assets

Contracted concessional assets (Tables)	12 Months Ended
	Dec. 31, 2017
Contracted concessional assets [Abstract]
Movements of contracted concessional assets	a) The following table shows the movements of contracted concessional assets included in the heading “Contracted Concessional assets” for 2017: Cost Total as of January 1, 2017 10,067,596 Additions 15,426 Subtractions (42,500 ) Translation differences 593,247 Total as of December 31, 2017 10,633,769 Accumulated amortization Total as of January 1, 2017 (1,143,324 ) Additions (309,846 ) Translation differences (96,329 ) Total accum. amort. as of December 31, 2017 (1,549,499 ) Net balance at December 31, 2017 9,084,270 b) The following table shows the movements of contracted concessional assets included in the heading “Contracted Concessional assets” for 2016: Cost Total as of January 1, 2016 10,126,023 Additions 6,346 Translation differences (68,199 ) Change in the scope of the consolidated financial statements 5,876 Reclassification and other movements (2,450 ) Total as of December 31, 2016 10,067,596 Accumulated amortization Total as of January 1, 2016 (825,126 ) Additions (332,925 ) Change in the scope of the consolidated financial statements (2,381 ) Translation differences 17,108 Total accum. amort. as of December 31, 2016 (1,143,324 ) Net balance at December 31, 2016 8,924,272

Investments carried under the37

Investments carried under the equity method (Tables)	12 Months Ended
	Dec. 31, 2017
Investments carried under the equity method [Abstract]
Investments in associates	The table below shows the breakdown and the movement of the investments held in associates for 2017 and 2016: Investments in associates 2017 2016 Initial balance 55,009 56,181 Share of (loss)/profit 5,351 6,646 Dividend distribution (2,454 ) (3,954 ) Equity distribution (549 ) (3,099 ) Currency translation differences (1,573 ) (765 ) Final balance 55,784 55,009
Stand-alone amounts for associated companies	The tables below show a breakdown of stand-alone amounts of assets, revenues and profit and loss as well as other information of interest for the years 2017 and 2016 for the associated companies: Company % Shares Non- current assets Current assets Non- current liabilities Current liabilities Revenue Operating profit/ (loss) Net profit/ (loss) Investment under the equity method Evacuación Valdecaballeros, S.L. 57.16 21,306 841 373 451 298 (708 ) (730 ) 9,175 Myah Bahr Honaine, S.P.A.(*) 25.50 195,275 64,114 91,205 12,649 46,767 28,468 24,464 43,365 Pectonex, R.F. Proprietary Limited 50.00 3,904 - - 2 - (206 ) (206 ) 3,244 Evacuación Villanueva del Rey, S.L 40.02 3,526 53 2,265 190 - 37 - - As of December 31, 2017 240,011 65,008 93,843 13,292 47,065 27,591 23,528 55,784 Company % Shares Non- current assets Current assets Non- current liabilities Current liabilities Revenue Operating profit/ (loss) Net profit/ (loss) Investment under the equity method Evacuación Valdecaballeros, S.L. 57.16 19,283 931 306 532 537 (545 ) (565 ) 9,528 Myah Bahr Honaine, S.P.A.(*) 25.50 202,150 67,120 104,704 14,158 52,770 34,247 29,990 42,056 Pectonex, R.F. Proprietary Limited 50.00 3,730 - - 1 - (187 ) (187 ) 3,425 Evacuación Villanueva del Rey, S.L 40.02 3,251 17 2,118 142 - 31 - - As of December 31, 2016 228,684 68,068 107,128 14,833 53,307 33,546 29,238 55,009

Financial instruments by cate38

Financial instruments by category (Tables)	12 Months Ended
	Dec. 31, 2017
Financial instruments by category [Abstract]
Financial assets	Notes Loans and receivables / payables Available for sale financial assets Hedging derivatives Balance as of December 31, 2017 Derivative assets 9 - - 8,230 8,230 Investment in Ten West Link 2,088 - - 2,088 Abengoa debt and Equity instruments - 1,715 - 1,715 Other financial investments 243,347 - - 243,347 Clients and other receivables 11 244,449 - - 244,449 Cash and cash equivalents 12 669,387 - - 669,387 Total financial assets 1,159,271 1,715 8,230 1,169,216 Notes Loans and receivables / payables Available for sale financial assets Hedging derivatives Balance as of December 31, 2016 Derivative assets 9 - - 3,822 3,822 Preferred equity in ACBH - 30,488 - 30,488 Other financial investments 263,501 - - 263,501 Clients and other receivables 11 207,621 - - 207,621 Cash and cash equivalents 12 594,811 - - 594,811 Total financial assets 1,065,933 30,488 3,822 1,100,243
Financial liabilities	Corporate debt 14 643,083 - - 643,083 Project debt 15 5,475,208 - - 5,475,208 Related parties – non-current 10 141,031 - - 141,031 Trade and other current liabilities 17 155,144 - - 155,144 Derivative liabilities 9 - - 329,731 329,731 Total financial liabilities 6,414,466 - 329,731 6,744,197 Corporate debt 14 668,201 - - 668,201 Project debt 15 5,330,467 - - 5,330,467 Related parties – non-current 10 101,750 - - 101,750 Trade and other current liabilities 17 160,505 - - 160,505 Derivative liabilities 9 - - 349,266 349,266 Total financial liabilities 6,260,923 - 349,266 6,610,189

Derivative financial instrume39

Derivative financial instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative financial instruments [Abstract]
Fair value amount of derivative financial instruments	The breakdowns of the fair value amount of the derivative financial instruments as of December 31, 2017 and 2016 are as follows: Balance as of December 31, 2017 Balance as of December 31, 2016 Assets Liabilities Assets Liabilities Derivatives - cash flow hedge 8,230 329,731 3,822 349,266
Maturities of notional and fair value amounts of interest rate derivatives designated as cash flow hedges	The table below shows a breakdown of the maturities of notional amounts of derivatives designated as cash flow hedges as of December 31, 2017 and 2016. Notionals Balance as of December 31, 2017 Balance as of December 31, 2016 Cap Swap Cap Swap Up to 1 year 42,324 139,939 24,261 75,837 Between 1 and 2 years 45,422 94,285 25,934 199,832 Between 2 and 3 years 48,215 103,536 27,880 83,897 Subsequent years 620,378 1,893,850 400,239 1,500,789 Total $ 756,339 $ 2,231,611 $ 478,314 $ 1,860,355 The table below shows a breakdown of the maturity of the fair values of derivatives designated as cash flow hedges as of December 31, 2017 and 2016. The net position of the fair value of caps and swaps for each year end reconciles with the net position of derivative assets and derivative liabilities in the consolidated statement of financial position: Fair value Balance as of December 31, 2017 Balance as of December 31, 2016 Cap Swap Cap Swap Up to 1 year 347 (13,224 ) 250 (12,383 ) Between 1 and 2 years 978 (14,378 ) 262 (14,927 ) Between 2 and 3 years 396 (15,923 ) 275 (13,957 ) Subsequent years 6,509 (286,206 ) 3,035 (307,999 ) Total $ 8,230 (329,731 ) $ 3,822 (349,266 )

Related parties (Tables)

Related parties (Tables)	12 Months Ended
	Dec. 31, 2017
Related parties [Abstract]
Related party receivables and payables	Details of balances with related parties as of December 31, 2017 and 2016 are as follows: Balance as of December 31, 2017 2016 Credit receivables (current) 11,567 12,031 Total current receivables with related parties 11,567 12,031 Credit receivables (non-current) 2,108 30,505 Total non-current receivables with related parties 2,108 30,505 Trade payables (current) 63,409 61,338 Total current payables with related parties 63,409 61,338 Credit payables (non-current) 141,031 101,750 Total non-current payables with related parties 141,031 101,750
Related party transactions	The transactions carried out by entities included in these consolidated financial statements with related parties not included in the consolidation perimeter of Atlantica Yield, primarily with Abengoa and with subsidiaries of Abengoa, during the twelve-month periods ended December 31, 2017, 2016 and 2015 have been as follows: For the year ended December 31, 2017 2016 2015 Sales - - 44,260 Services rendered 3,495 1,220 523 Services received (114,416 ) (115,779 ) (106,737 ) Financial income 74 60 1,466 Financial expenses (1,154 ) (2,460 ) (1,968 )

Clients and other receivable (T

Clients and other receivable (Tables)	12 Months Ended
	Dec. 31, 2017
Clients and other receivable [Abstract]
Clients and other receivable	Clients and other receivable as of December 31, 2017 and 2016, consist of the following: Balance as of December 31, 2017 2016 Trade receivables 186,728 151,199 Tax receivables 39,607 29,705 Prepayments 6,375 10,261 Other accounts receivable 11,739 16,456 Total 244,449 207,621
Trade receivables in foreign currency	Trade receivables in foreign currency as of December 31, 2017 and 2016, are as follows: Balance as of December 31, 2017 2016 Euro 109,165 98,798 Rand 23,792 12,807 Other 7,363 7,151 Total 140,320 118,756
Maturity of trade receivables	The following table shows the maturity of Trade receivables as of December 31, 2017 and 2016: Balance as of December 31, 2017 2016 Up to 3 months 186,728 151,199 Total 186,728 151,199

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2017
Cash and cash equivalents [Abstract]
Cash and cash equivalents	The following table shows the detail of Cash and cash equivalents as of December 31, 2017 and 2016: Balance as of December 31, 2017 2016 Cash at bank and on hand 669,387 594,811 Total 669,387 594,811 The following breakdown shows the main currencies in which cash and cash equivalent balances are denominated: Balance as of December 31, Currency 2017 2016 U.S. dollar 319,400 343,954 Euro 288,625 196,382 Algerian Dinar 13,628 10,736 South African Rand 40,999 39,689 Others 6,735 4,050 Total 669,387 594,811

Corporate debt (Tables)

Corporate debt (Tables)	12 Months Ended
	Dec. 31, 2017
Corporate debt [Abstract]
Corporate debt	The breakdown of the corporate debt as of December 31, 2017 and 2016 is as follows: Balance as of December 31, Non-current 2017 2016 Credit Facilities with financial entities 320,783 123,804 Notes and Bonds 253,393 252,536 Total Non-Current 574,176 376,340 Balance as of December 31, Current 2017 2016 Credit Facilities with financial entities 65,833 289,035 Notes and Bonds 3,074 2,826 Total Current 68,907 291,861
Repayment schedule for corporate debt	The repayment schedule for the Corporate debt, at the end of 2017 is as follows: 2018 2019 2020 2021 2022 Subsequent years Total Credit Facility Tranche A 53,778 - - - - - 53,778 Note Issuance Facility 107 - - - 107,316 213,467 320,890 Credit Facility 2017 11,948 - - - - - 11,948 2019 Notes 3,074 253,393 - - - - 256,467 Total 68,907 253,393 - - 107,316 213,467 643,083
Movement in corporate debt	The following table details the movement in Corporate debt for the year 2017, split between cash and non-cash items: January 1, 2017 Cash Flow Non-cash changes December 31, 2017 Corporate debt 668,201 (68,372 ) 43,254 643,083

Project debt (Tables)

Project debt (Tables)	12 Months Ended
	Dec. 31, 2017
Project debt [Abstract]
Project debt	The variations for 2017 and 2016 of project debt have been the following: Project debt - long term Project debt - short term Total Balance as of December 31, 2016 4,629,184 701,283 5,330,467 Increases 52,027 304,707 356,734 Decreases (42,560 ) (509,131 ) (551,691 ) Currency translation differences 316,646 23,052 339,698 Reclassifications 273,620 (273,620 ) - Balance as of December 31, 2017 5,228,917 246,291 5,475,208 Project debt - long term Project debt - short term Total Balance as of December 31, 2015 3,574,464 1,896,205 5,470,669 Increases 36,842 329,434 366,276 Decreases - (480,969 ) (480,969 ) Currency translation differences (64,426 ) 38,917 (25,509 ) Reclassifications 1,082,304 (1,082,304 ) - Balance as of December 31, 2016 4,629,184 701,283 5,330,467
Repayment schedule for project debt	The repayment schedule for Project debt in accordance with the financing arrangements, at the end of 2017 is as follows and is consistent with the projected cash flows of the related projects. 2018 2019 2020 2021 2022 Subsequent years Total Interest Repayment Nominal repayment 21,612 224,679 246,471 265,002 280,303 313,559 4,123,582 5,475,208
Movement in project debt	The following table details the movement in Project debt for the year 2017, split between cash and non-cash items: January 1, 2017 Cash Flow Non-cash changes December 31, 2017 Project debt 5,330,467 (248,472 ) 393,212 5,475,208
Foreign currency-denominated project debt	The equivalent in U.S. dollars of the most significant foreign-currency-denominated debts held by the Company is as follows: Balance as of December 31, Currency 2017 2016 Euro 2,286,771 2,102,985 Algerian Dinar 35,093 41,598 Rand 456,179 419,708 Total 2,778,043 2,564,291

Grants and other liabilities (T

Grants and other liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Grants and other liabilities [Abstract]
Grants and other non-current liabilities	Balance as of December 31, 2017 2016 Grants 1,225,877 1,297,755 Other liabilities 410,183 314,290 Grant and other non-current liabilities 1,636,060 1,612,045

Trade payables and other curr46

Trade payables and other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Trade payables and other current liabilities [Abstract]
Trade payable and other current liabilities	Trade payable and other current liabilities as of December 31, 2017 and 2016 are as follows: Balance as of December 31, Item 2017 2016 Trade accounts payables 107,662 121,527 Down payments from clients 6,466 6,153 Suppliers of concessional assets current 236 380 Liberty (see Note 16) - 21,461 Other accounts payable 40,780 10,984 Total 155,144 160,505

Income Tax (Tables)

Income Tax (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax [Abstract]
Analysis of deferred tax assets and liabilities	As of December 31, 2017, and 2016, the analysis of deferred tax assets and deferred tax liabilities is as follows: Deferred tax assets Balance as of December 31, Concept 2017 2016 Net tax credits for operating losses carryforwards 71,219 102,804 Temporary differences derivatives financial instruments 93,719 99,930 Other temporary differences 198 157 Total deferred tax assets 165,136 202,891 Deferred tax liabilities Balance as of December 31, Concept 2017 2016 Temporary differences tax/book amortization 113,432 28,810 Other temporary differences tax/book value of contracted concessional assets 66,247 61,818 Other temporary differences 6,904 4,409 Total deferred tax liabilities 186,583 95,037
Movements in deferred tax assets and liabilities	The movements in deferred tax assets and liabilities during the years ended December 31, 2017 and 2016 were as follows: Deferred tax assets Amount As of January 1, 2016 191,314 Increase/decrease through the consolidated income statement 16,033 Increase/decrease through other consolidated comprehensive income (equity) (5,701 ) Other movements 1,245 As of December 31, 2016 202,891 Increase/decrease through the consolidated income statement (31,421 ) Increase/decrease through other consolidated comprehensive income (equity) (13,312 ) Other movements 6,978 As of December 31, 2017 165,136 Deferred tax liabilities Amount As of January 1, 2016 79,654 Increase/decrease through the consolidated income statement 16,681 Increase/decrease through other consolidated comprehensive income (equity) (62 ) Other movements (1,236 ) As of December 31, 2016 95,037 Increase/decrease through the consolidated income statement 86,418 Increase/decrease through other consolidated comprehensive income (equity) - Other movements 5,128 As of December 31, 2017 186,583
Income tax benefit/(expense)	Details for income tax for the years ended December 31, 2017, 2016 and 2015 are as follows: For the twelve-month period ended December 31, Item 2017 2016 2015 Current tax (1,998 ) (1,018 ) (2,182 ) Deferred tax (117,839 ) (648 ) (21,608 ) - relating to the origination and reversal of temporary differences (98,508 ) (648 ) (22,492 ) - relating to changes in tax rates (19,331 ) - 884 Total income tax benefit/(expense) (119,837 ) (1,666 ) (23,790 )
Effective income tax rate reconciliation	The reconciliation between the theoretical income tax resulting from applying an average statutory tax rate to income/(loss) before income tax and the actual income tax expense recognized in the consolidated income statements for the years ended December 31, 2017, 2016 and 2015, are as follows: For the year ended December 31, Concept 2017 2016 2015 Consolidated income / (loss) before taxes 14,950 3,333 (174,396 ) Average statutory tax rate 30 % 30 % 30 % Corporate income tax at average statutory tax rate (4,485 ) (1,000 ) 52,319 Income tax of associates, net 1,765 2,110 2,341 Differences in foreign tax rates 3,304 (4,930 ) (2,389 ) Permanent differences 19,324 11,121 (19,456 ) Incentives, deductions, and unrecognized tax losses carryforwards (20,994 ) (11,110 ) (58,039 ) Change in corporate income tax (19,331 ) - 884 U.S. Internal Revenue Code Section 382 (96,328 ) - - Other non-taxable income/(expense) (3,092 ) 2,143 550 Corporate income tax (119,837 ) (1,666 ) (23,790 )

Third-party guarantees and co48

Third-party guarantees and commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Third-party guarantees and commitments [Abstract]
Contractual obligations	The following table shows the breakdown of the third-party commitments and contractual obligations as of December 31, 2017 and 2016: 2017 Total 2018 2019 and 2020 2021 and 2022 Subsequent Corporate debt 643,083 68,907 253,393 107,316 213,467 Loans with credit institutions (project debt) 4,628,289 215,117 457,853 539,466 3,415,853 Notes and bonds (project debt) 846,919 31,174 53,620 54,395 707,730 Purchase commitments 3,149,813 141,867 230,014 259,845 2,518,087 Accrued interest estimate during the useful life of loans 3,129,321 340,481 630,108 559,856 1,598,876 2016 Total 2017 2018 and 2019 2020 and 2021 Subsequent Corporate debt 668,201 291,861 376,340 - - Loans with credit institutions (project debt)* 4,498,930 183,929 388,679 459,361 3,466,961 Notes and bonds (project debt) 831,538 27,225 49,422 48,740 706,151 Purchase commitments 2,894,146 136,032 263,398 246,904 2,247,812 Accrued interest estimate during the useful life of loans 3,356,750 332,408 617,852 543,927 1,862,563 * According to contracted maturities.

Other operating income and ex49

Other operating income and expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Other operating income and expenses [Abstract]
Other operating income	The table below shows the detail of Other operating income and expenses for the years ended December 31, 2017, 2016 and 2015: For the twelve-month year ended December 31, Other operating income 2017 2016 2015 Grants 59,707 59,085 67,859 Income from various services and insurance proceeds 21,137 6,453 998 Total 80,844 65,538 68,857
Other operating expenses	For the twelve-month year ended December 31, Other operating expenses 2017 2016 2015 Leases and fees (6,641 ) (5,309 ) (3,865 ) Operation and maintenance (129,873 ) (133,292 ) (116,405 ) Independent professional services (36,178 ) (30,515 ) (19,046 ) Supplies (20,350 ) (17,177 ) (18,001 ) Insurance (24,289 ) (23,390 ) (20,277 ) Levies and duties (52,409 ) (44,440 ) (32,352 ) Other expenses (14,721 ) (6,195 ) (14,882 ) Total (284,461 ) (260,318 ) (224,828 )

Financial Income and expenses (

Financial Income and expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Financial income and expenses [Abstract]
Financial income	The following table sets forth financial income and expenses for the years ended December 31, 2017, 2016 and 2015: For the year ended December 31, Financial income 2017 2016 2015 Interest income from loans and credits 325 286 933 Interest rates benefits derivatives: cash flow hedges 682 3,012 2,531 Total 1,007 3,298 3,464
Financial expenses	For the year ended December 31, Financial expenses 2017 2016 2015 Expenses due to interest: - Loans from credit entities (253,660 ) (242,919 ) (197,929 ) - Other debts (137,562 ) (90,995 ) (81,853 ) Interest rates losses derivatives: cash flow hedges (72,495 ) (74,093 ) (54,139 ) Total (463,717 ) (408,007 ) (333,921 )
Other net financial income and expenses	The following table sets out Other net financial income and expenses for the years 2017, 2016 and 2015: For the year ended December 31, Other financial income / (expenses) 2017 2016 2015 Dividend from ACBH (Brazil) 10,383 27,948 18,400 Impairment preferred equity investment in ACBH (see Note 8) - (22,076 ) (210,435 ) Other financial income 28,809 13,027 1,520 Other financial losses (20,758 ) (10,394 ) (9,638 ) Total 18,434 8,505 (200,153 )

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings per share [Abstract]
Earnings per share	Basic earnings per share for the year 2017 has been calculated by dividing the profit/(loss) attributable to equity holders of the company by the number of shares outstanding. Diluted earnings per share equals basic earnings per share for the period presented. For the year ended December 31, Item 2017 2016 2015 Profit/(loss) from continuing operations attributable to Atlantica Yield Plc. (111,804 ) (4,855 ) (209,005 ) Profit/(loss) from discontinuing operations attributable to Atlantica Yield Plc. - - - Average number of ordinary shares outstanding (thousands) - basic and diluted 100,217 100,217 92,795 Earnings per share from continuing operations (US dollar per share) - basic and diluted (1.12 ) (0.05 ) (2.25 ) Earnings per share from discontinuing operations (US dollar per share) - basic and diluted - - - Earnings per share from profit/ (loss) for the period (US dollar per share) - basic and diluted (1.12 ) (0.05 ) (2.25 )

Nature of the business, Descrip

Nature of the business, Description (Details) $ / shares in Units, $ in Thousands	May 14, 2015$ / shares	Jan. 22, 2015USD ($)$ / shares	Jun. 18, 2014USD ($)$ / sharesshares	Dec. 31, 2017	Dec. 31, 2014USD ($)ConcessionalAsset	Feb. 28, 2017
Nature of the business [Abstract]
Shares issued (in shares) | shares			24,850,000
Share price (in dollars per share) | $ / shares	$ 33.14		$ 29
Proceeds from issuing shares			$ 720,650
Interest consideration transferred						12.50%
Subsidiary of Abengoa [Member]
Nature of the business [Abstract]
Shares purchased by underwriters (in shares) | shares			3,727,500
Total proceeds from offering			$ 828,748
Abengoa [Member]
Nature of the business [Abstract]
Ownership interest				41.47%
Share price (in dollars per share) | $ / shares		$ 31
Proceeds from issuing shares		$ 327,980
Number of concessional assets contributed | ConcessionalAsset					10
Interest consideration transferred					64.28%
Cash consideration transferred					$ 655,300
Cash retained for liquidity purposes					$ 30,000

Nature of the business, Assets

Nature of the business, Assets acquired (Details) $ in Thousands		Jul. 20, 2017USD ($)MW	Feb. 28, 2017mi	Jan. 07, 2016USD ($)	Dec. 31, 2017	Dec. 31, 2016MW	Aug. 03, 2016USD ($)	Jul. 30, 2015
Nature of the business [Abstract]
Percentage interest acquired			12.50%
Length of transmission lines | mi			114
Peru [Member]
Nature of the business [Abstract]
Gross capacity | MW		4
Acquisition purchase price		$ 9,000
Honaine [Member]
Nature of the business [Abstract]
Ownership interest	[1]				25.50%
Skikda [Member]
Nature of the business [Abstract]
Ownership interest	[2]				34.20%
Helioenergy 1/2 [Member]
Nature of the business [Abstract]
Ownership interest					100.00%
Helios 1/2 [Member]
Nature of the business [Abstract]
Ownership interest					100.00%
Solnova 1/3/4 [Member]
Nature of the business [Abstract]
Ownership interest					100.00%
Kaxu [Member]
Nature of the business [Abstract]
Percentage interest acquired								51.00%
Ownership interest	[3]				51.00%
Solaben 1/6 [Member]
Nature of the business [Abstract]
Ownership interest					100.00%
Solacor 1/2 [Member]
Nature of the business [Abstract]
Percentage interest acquired				13.00%		13.00%
Acquisition purchase price				$ 19,923
Ownership interest	[4]				87.00%
Seville PV [Member]
Nature of the business [Abstract]
Percentage interest acquired						80.00%	80.00%
Gross capacity | MW						1
Acquisition purchase price							$ 3,214
Ownership interest	[5]				80.00%
JGC [Member] | Solacor 1/2 [Member]
Nature of the business [Abstract]
Ownership interest				13.00%		13.00%
[1]	Algerian Energy Company, SPA owns 49% of Honaine and Valoriza Agua, S.L. owns the remaining 25.5%.
[2]	Algerian Energy Company, SPA owns 49% of Skikda and Valoriza Agua, S.L. owns the remaining 16.83%.
[3]	Kaxu is owned by the Company (51%), Industrial Development Corporation of South Africa (29%) and Kaxu Community Trust (20%).
[4]	JGC, a Japanese engineering company, holds 13% of the shares in each of Solacor 1 and Solacor 2.
[5]	Instituto para la Diversificacion y Ahorro de la Energia ("Idae"), a Spanish state owned company, holds 20% of the shares in Seville PV.

Nature of the business, Concess

Nature of the business, Concessional assets owned (Details) - USD ($) $ in Thousands		Jan. 07, 2016	Sep. 30, 2013	Dec. 31, 2017	Dec. 31, 2016
ACT [Member]
Nature of the business [Abstract]
Type				Efficient natural gas
Ownership				100.00%
Location				Mexico
Currency	[1]			USD
Capacity (gross)				300 MW
Counterparty credit ratings	[2]			BBB+/A3/BBB+
COD	[3]			2Q 2013
Contract years left	[4]			15 years
ATN [Member]
Nature of the business [Abstract]
Type				Transmission line
Ownership				100.00%
Location				Peru
Currency	[1]			USD
Capacity (gross)				362 miles
Counterparty credit ratings	[2]			BBB+/A3/BBB+
COD	[3]			1Q 2011
Contract years left	[4]			23 years
ATS [Member]
Nature of the business [Abstract]
Type				Transmission line
Ownership				100.00%
Location				Peru
Currency	[1]			USD
Capacity (gross)				569 miles
Counterparty credit ratings	[2]			BBB+/A3/BBB+
COD	[3]			1Q 2014
Contract years left	[4]			26 years
ATN2 [Member]
Nature of the business [Abstract]
Type				Transmission line
Ownership				100.00%
Location				Peru
Currency	[1]			USD
Capacity (gross)				81 miles
Counterparty credit ratings	[2]			Not rated
COD	[3]			2Q 2015
Contract years left	[4]			15 years
Quadra 1 [Member]
Nature of the business [Abstract]
Type				Transmission line
Ownership				100.00%
Location				Chile
Currency	[1]			USD
Capacity (gross)				49 miles
Counterparty credit ratings	[2]			Not rated
COD	[3]			2Q 2014
Contract years left	[4]			17 years
Quadra 2 [Member]
Nature of the business [Abstract]
Type				Transmission line
Ownership				100.00%
Location				Chile
Currency	[1]			USD
Capacity (gross)				32 miles
Counterparty credit ratings	[2]			Not rated
COD	[3]			1Q 2014
Contract years left	[4]			17 years
Palmucho [Member]
Nature of the business [Abstract]
Type				Transmission line
Ownership				100.00%
Location				Chile
Currency	[1]			USD
Capacity (gross)				6 miles
Counterparty credit ratings	[2]			BBB+/Baa2/BBB+
COD	[3]			4Q 2007
Contract years left	[4]			20 years
Skikda [Member]
Nature of the business [Abstract]
Type				Water
Ownership	[5]			34.20%
Location				Algeria
Currency	[1]			USD
Capacity (gross)				3.5 M ft3/day
Counterparty credit ratings	[2]			Not rated
COD	[3]			1Q 2009
Contract years left	[4]			16 years
Skikda [Member] | Algerian Energy Company, SPA [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				49.00%
Skikda [Member] | Valoriza Agua, S.L. [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				16.83%
Honaine [Member]
Nature of the business [Abstract]
Type				Water
Ownership	[6]			25.50%
Location				Algeria
Currency	[1]			USD
Capacity (gross)				7 M ft3/day
Counterparty credit ratings	[2]			Not rated
COD	[3]			3Q 2012
Contract years left	[4]			20 years
Honaine [Member] | Algerian Energy Company, SPA [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				49.00%
Honaine [Member] | Valoriza Agua, S.L. [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				25.50%
PS10/PS20 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				31 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			1Q 2007 & 2Q 2009
PS10 [Member]
Nature of the business [Abstract]
Contract years left	[4]			14 years
PS20 [Member]
Nature of the business [Abstract]
Contract years left	[4]			16 years
Solana [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Ownership interest type	[7]			Class B
Location				Arizona (USA)
Currency	[1]			USD
Capacity (gross)				280 MW
Counterparty credit ratings	[2]			A-/A3/A-
COD	[3]			4Q 2013
Contract years left	[4]			26 years
Solana [Member] | Liberty Interactive Corporation [Member]
Nature of the business [Abstract]
Class A membership investment			$ 300,000
Percentage of dividends and taxable loss once certain conditions met			22.60%
Solana [Member] | Liberty Interactive Corporation [Member] | Bottom of Range [Member]
Nature of the business [Abstract]
Percentage of dividends and taxable loss received			54.06%
Solana [Member] | Liberty Interactive Corporation [Member] | Top of Range [Member]
Nature of the business [Abstract]
Percentage of dividends and taxable loss received			61.20%
Mojave [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Location				California (USA)
Currency	[1]			USD
Capacity (gross)				280 MW
Counterparty credit ratings	[2]			A-/A3/A-
COD	[3]			4Q 2014
Contract years left	[4]			22 years
Solaben 2 & 3 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership	[8]			70.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				2x50 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			3Q 2012 & 2Q 2012
Solaben 2 & 3 [Member] | Itochu Corporation [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				30.00%
Solaben 2 [Member]
Nature of the business [Abstract]
Contract years left	[4]			20 years
Solaben 3 [Member]
Nature of the business [Abstract]
Contract years left	[4]			19 years
Solacor 1 & 2 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership	[9]			87.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				2x50 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			1Q 2012 & 1Q 2012
Contract years left	[4]			19 years
Solacor 1 & 2 [Member] | JGC [Member]
Nature of the business [Abstract]
Ownership		13.00%			13.00%
Percentage of non-controlling interests				13.00%
Helioenergy 1 & 2 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				2x50 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			3Q 2011 & 4Q 2011
Contract years left	[4]			19 years
Helios 1 & 2 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				2x50 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			3Q 2012 & 3Q 2012
Contract years left	[4]			20 years
Solnova 1, 3 & 4 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				3x50 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			2Q 2010 & 2Q 2010 & 3Q 2010
Solnova 1 [Member]
Nature of the business [Abstract]
Contract years left	[4]			17 years
Solnova 3 [Member]
Nature of the business [Abstract]
Contract years left	[4]			17 years
Solnova 4 [Member]
Nature of the business [Abstract]
Contract years left	[4]			18 years
Solaben 1 & 6 [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership				100.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				2x50 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			3Q 2013
Contract years left	[4]			21 years
Kaxu [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership	[10]			51.00%
Location				South Africa
Currency	[1]			Rand
Capacity (gross)				100 MW
Counterparty credit ratings	[2],[11]			BB/Baa3/BB+
COD	[3]			1Q 2015
Contract years left	[4]			17 years
Kaxu [Member] | IDC [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				29.00%
Kaxu [Member] | Kaxu Community Trust [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				20.00%
Palmatir [Member]
Nature of the business [Abstract]
Type				Renewable (Wind)
Ownership				100.00%
Location				Uruguay
Currency	[1]			USD
Capacity (gross)				50 MW
Counterparty credit ratings	[2],[12]			BBB/Baa2/BBB-
COD	[3]			2Q 2014
Contract years left	[4]			16 years
Cadonal [Member]
Nature of the business [Abstract]
Type				Renewable (Wind)
Ownership				100.00%
Location				Uruguay
Currency	[1]			USD
Capacity (gross)				50 MW
Counterparty credit ratings	[2],[12]			BBB/Baa2/BBB-
COD	[3]			4Q 2014
Contract years left	[4]			17 years
Seville PV [Member]
Nature of the business [Abstract]
Type				Renewable (Solar)
Ownership	[13]			80.00%
Location				Spain
Currency	[1]			Euro
Capacity (gross)				1 MW
Counterparty credit ratings	[2]			BBB+/Baa2/A-
COD	[3]			3Q 2006
Contract years left	[4]			18 years
Seville PV [Member] | Idae [Member]
Nature of the business [Abstract]
Percentage of non-controlling interests				20.00%
[1]	Certain contracts denominated in U.S. dollars are payable in local currency.
[2]	Reflects the counterparty's credit ratings issued by Standard & Poor's Ratings Services, or S&P, Moody's Investors Service Inc., or Moody's, and Fitch Ratings Ltd, or Fitch.
[3]	Commercial Operation Date ("COD").
[4]	As of December 31, 2017.
[5]	Algerian Energy Company, SPA owns 49% of Skikda and Valoriza Agua, S.L. owns the remaining 16.83%.
[6]	Algerian Energy Company, SPA owns 49% of Honaine and Valoriza Agua, S.L. owns the remaining 25.5%.
[7]	On September 30, 2013, Liberty Interactive Corporation invested $300,000 thousand in Class A membership interests in exchange for a share of the dividends and taxable loss generated by Solana. As a result of the agreement, Liberty Interactive Corporation will receive between 54.06% and 61.20% of both dividends and taxable loss generated during a period of approximately five years; such percentage will decrease to 22.60% thereafter.
[8]	Itochu Corporation, a Japanese trading company, holds 30% of the shares in each of Solaben 2 and Solaben 3.
[9]	JGC, a Japanese engineering company, holds 13% of the shares in each of Solacor 1 and Solacor 2.
[10]	Kaxu is owned by the Company (51%), Industrial Development Corporation of South Africa (29%) and Kaxu Community Trust (20%).
[11]	Refers to the credit rating of the Republic of South Africa. The offtaker is Eskom, which is a state-owned utility company in South Africa.
[12]	Refers to the credit rating of Uruguay, as UTE (Administracion Nacional de Usinas y Transmisoras Electricas) is unrated.
[13]	Instituto para la Diversificacion y Ahorro de la Energia ("Idae"), a Spanish state owned company, holds 20% of the shares in Seville PV.

Nature of the business, Financi

Nature of the business, Financing arrangements (Details) € in Millions, $ in Millions	Nov. 01, 2017	Nov. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Feb. 10, 2017USD ($)	Feb. 10, 2017EUR (€)	Feb. 03, 2017
Note Issuance Facility [Member]
Financing arrangements [Abstract]
Principal amount					$ 330	€ 275
Abengoa [Member]
Financing arrangements [Abstract]
Percentage of financial liabilities approved							94.00%
Minimum ownership requirement percentage		30.00%		35.00%
Ownership interest			41.47%
Percentage of outstanding shares pledged as collateral			41.44%
Stake in parent to be sold to Algonquin	25.00%
Remaining ownership percentage	16.50%
Abengoa [Member] | Solana and Mojave [Member]
Financing arrangements [Abstract]
Minimum ownership requirement percentage		16.00%	30.00%

Significant accounting polici56

Significant accounting policies, Basis of preparation (Details)	Jun. 13, 2014ConcessionalAsset
Significant accounting policies [Abstract]
Number of selected assets subject to ROFO Agreement	4

Significant accounting polici57

Significant accounting policies, Asset impairment (Details)	Dec. 31, 2017
EMEA [Member]
Cash-generating units [Abstract]
Growth rate	0.00%
EMEA [Member] | Bottom of Range [Member]
Cash-generating units [Abstract]
Discount rate	4.00%
EMEA [Member] | Top of Range [Member]
Cash-generating units [Abstract]
Discount rate	6.00%
North America [Member]
Cash-generating units [Abstract]
Growth rate	0.00%
North America [Member] | Bottom of Range [Member]
Cash-generating units [Abstract]
Discount rate	4.00%
North America [Member] | Top of Range [Member]
Cash-generating units [Abstract]
Discount rate	6.00%
South America [Member]
Cash-generating units [Abstract]
Growth rate	0.00%
South America [Member] | Bottom of Range [Member]
Cash-generating units [Abstract]
Discount rate	5.00%
South America [Member] | Top of Range [Member]
Cash-generating units [Abstract]
Discount rate	7.00%

Financial risk management (Deta

Financial risk management (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Rate Risk [Member]
Financial risk management [Abstract]
Forecasted increase in benchmark interest rate	0.25%
Forecasted loss on cash flow hedges due to increase in benchmark interest rate	$ (228)	$ (2,563)	$ (1,795)
Forecasted increase in hedging reserves due to increase in benchmark interest rate	$ 37,767	$ 37,290	$ 41,702
Interest Rate Risk [Member] | Euros [Member]
Financial risk management [Abstract]
Maturity date	2,030
Interest Rate Risk [Member] | Euros [Member] | Bottom of Range [Member]
Financial risk management [Abstract]
Percentage of notional amount of debt hedged	87.00%
Interest rate	3.20%
Interest Rate Risk [Member] | Euros [Member] | Top of Range [Member]
Financial risk management [Abstract]
Percentage of notional amount of debt hedged	100.00%
Interest rate	4.87%
Interest Rate Risk [Member] | U.S. Dollars [Member]
Financial risk management [Abstract]
Maturity date	2,032
Interest Rate Risk [Member] | U.S. Dollars [Member] | Bottom of Range [Member]
Financial risk management [Abstract]
Percentage of notional amount of debt hedged	70.00%
Interest rate	2.32%
Interest Rate Risk [Member] | U.S. Dollars [Member] | Top of Range [Member]
Financial risk management [Abstract]
Percentage of notional amount of debt hedged	100.00%
Interest rate	5.27%
Currency Risk [Member]
Financial risk management [Abstract]
Net Euro exposure percentage for next fiscal year	100.00%
Net Euro exposure percentage for following fiscal period	75.00%

Financial information by segm59

Financial information by segment, Business sectors (Details) ft³ / d in Millions	Jul. 20, 2017MW	Feb. 28, 2017mi	Dec. 31, 2017ft³ / dWindFarmPlantLineSolarPlatformmiMW	Dec. 31, 2016MW
Financial information by segment [Abstract]
Length of transmission lines | mi		114
Seville PV [Member]
Financial information by segment [Abstract]
Gross capacity				1
United States [Member] | Renewable Energy [Member] | Solana [Member]
Financial information by segment [Abstract]
Number of contracted assets | Plant			1
Gross capacity			280
United States [Member] | Renewable Energy [Member] | Mojave [Member]
Financial information by segment [Abstract]
Number of contracted assets | Plant			1
Gross capacity			280
Spain [Member] | Renewable Energy [Member]
Financial information by segment [Abstract]
Number of contracted assets | SolarPlatform			8
Spain [Member] | Renewable Energy [Member] | PS10/PS20 [Member]
Financial information by segment [Abstract]
Gross capacity			31
Spain [Member] | Renewable Energy [Member] | Solacor 1 and Solacor 2 [Member]
Financial information by segment [Abstract]
Gross capacity			100
Spain [Member] | Renewable Energy [Member] | Solaben 2 and 3 [Member]
Financial information by segment [Abstract]
Gross capacity			100
Spain [Member] | Renewable Energy [Member] | Helioenergy 1 and 2 [Member]
Financial information by segment [Abstract]
Gross capacity			100
Spain [Member] | Renewable Energy [Member] | Helios 1 and 2 [Member]
Financial information by segment [Abstract]
Gross capacity			100
Spain [Member] | Renewable Energy [Member] | Solnova 1, 3 and 4 [Member]
Financial information by segment [Abstract]
Gross capacity			150
Spain [Member] | Renewable Energy [Member] | Solaben 1 and 6 [Member]
Financial information by segment [Abstract]
Gross capacity			100
Spain [Member] | Renewable Energy [Member] | Seville PV [Member]
Financial information by segment [Abstract]
Gross capacity			1
South Africa [Member] | Renewable Energy [Member] | Kaxu [Member]
Financial information by segment [Abstract]
Number of contracted assets | Plant			1
Gross capacity			100
Uruguay [Member] | Renewable Energy [Member] | Palmatir [Member]
Financial information by segment [Abstract]
Number of contracted assets | WindFarm			1
Gross capacity			50
Uruguay [Member] | Renewable Energy [Member] | Cadonal [Member]
Financial information by segment [Abstract]
Number of contracted assets | WindFarm			1
Gross capacity			50
Mexico [Member] | Efficient Natural Gas [Member] | ACT [Member]
Financial information by segment [Abstract]
Gross capacity			300
Term of take-or-pay contract			20 years
Peru [Member]
Financial information by segment [Abstract]
Gross capacity	4
Peru [Member] | Electric Transmission [Member] | ATN, ATS and ATN2 [Member]
Financial information by segment [Abstract]
Number of contracted assets | Line			3
Length of transmission lines | mi			1,012
Chile [Member] | Electric Transmission [Member] | Quadra 1, Quadra 2, and Palmucho [Member]
Financial information by segment [Abstract]
Number of contracted assets | Line			3
Length of transmission lines | mi			87
Algeria [Member] | Water [Member] | Honaine and Skikda [Member]
Financial information by segment [Abstract]
Number of contracted assets | Plant			2
Aggregate capacity | ft³ / d			10.5

Financial information by segm60

Financial information by segment, Revenues and Further Adjusted EBITDA (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Customer	Dec. 31, 2016USD ($)Customer	Dec. 31, 2015USD ($)
Financial information by segment [Abstract]
Number of customers representing more than 10% of total revenues | Customer	3	3
Revenue	$ 1,008,381	$ 971,797	$ 790,881
Further Adjusted EBITDA	$ 779,310	$ 763,310	624,218
Renewable Energy [Member]
Financial information by segment [Abstract]
Number of customers representing more than 10% of total revenues | Customer	2	2
Revenue	$ 767,226	$ 724,325	543,012
Further Adjusted EBITDA	$ 569,193	$ 538,427	413,933
Efficient Natural Gas [Member]
Financial information by segment [Abstract]
Number of customers representing more than 10% of total revenues | Customer	1	1
Revenue	$ 119,784	$ 128,046	138,717
Further Adjusted EBITDA	106,140	106,492	107,671
Electric Transmission [Member]
Financial information by segment [Abstract]
Revenue	95,096	95,137	86,393
Further Adjusted EBITDA	87,695	104,795	89,047
Water [Member]
Financial information by segment [Abstract]
Revenue	26,275	24,288	22,759
Further Adjusted EBITDA	16,282	13,596	13,567
North America [Member]
Financial information by segment [Abstract]
Revenue	332,705	337,061	328,139
Further Adjusted EBITDA	282,328	284,691	279,559
South America [Member]
Financial information by segment [Abstract]
Revenue	120,797	118,764	112,480
Further Adjusted EBITDA	108,766	124,599	110,905
EMEA [Member]
Financial information by segment [Abstract]
Revenue	554,879	515,972	350,262
Further Adjusted EBITDA	$ 388,216	$ 354,020	$ 233,754

Financial information by segm61

Financial information by segment, Reconciliation of segment Further Adjusted EBITDA (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial information by segment [Abstract]
Loss attributable to the Company	$ (111,804)	$ (4,855)	$ (209,005)
Profit attributable to non-controlling interests	(6,917)	(6,522)	(10,819)
Income tax	119,837	1,666	23,790
Share of profits/(losses) of associates	5,351	6,646	7,844
Dividend from exchangeable preferred equity investment in ACBH (Note 21)	10,383	27,948	18,400
Financial expense, net	448,368	405,750	526,758
Depreciation, amortization, and impairment charges	310,960	332,925	261,301
Total segment Further Adjusted EBITDA	779,310	763,310	624,218
Reconciling Item [Member]
Financial information by segment [Abstract]
Profit attributable to non-controlling interests	6,917	6,522	10,819
Income tax	119,837	1,666	23,790
Share of profits/(losses) of associates	(5,351)	(6,646)	(7,844)
Dividend from exchangeable preferred equity investment in ACBH (Note 21)	10,383	27,948	18,400
Financial expense, net	448,368	405,750	526,758
Depreciation, amortization, and impairment charges	310,960	332,925	261,301
Allocated [Member]
Financial information by segment [Abstract]
Total segment Further Adjusted EBITDA	$ 779,310	$ 763,310	$ 624,219

Financial information by segm62

Financial information by segment, Assets and liabilities by geography (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets [Abstract]
Contracted concessional assets	$ 9,084,270	$ 8,924,272
Investments carried under the equity method	55,784	55,009	$ 56,181
Current financial investments	210,138	228,038
Cash and cash equivalents (project companies)	669,387	594,811	514,712	$ 354,154
Total assets	10,492,339	10,297,799
Liabilities [Abstract]
Long-term and short-term project debt	5,475,208	5,330,467	5,470,669
Grants and other liabilities	1,636,060	1,612,045
Long-term and short-term corporate debt	643,083	668,201
Total liabilities	8,596,886	8,338,688
Equity	1,895,453	1,959,111	$ 2,023,501	$ 1,839,631
Total liabilities and equity	10,492,339	10,297,799
North America [Member]
Assets [Abstract]
Contracted concessional assets	3,770,169	3,920,106
Investments carried under the equity method	0	0
Current financial investments	116,451	136,665
Cash and cash equivalents (project companies)	149,236	185,970
Total assets	4,035,856	4,242,741
Liabilities [Abstract]
Long-term and short-term project debt	1,821,102	1,870,861
Grants and other liabilities	1,593,048	1,575,303
Total liabilities	3,414,150	3,446,164
South America [Member]
Assets [Abstract]
Contracted concessional assets	1,100,778	1,144,712
Investments carried under the equity method	0	0
Current financial investments	59,831	62,215
Cash and cash equivalents (project companies)	42,548	40,015
Total assets	1,203,157	1,246,942
Liabilities [Abstract]
Long-term and short-term project debt	876,063	895,316
Grants and other liabilities	810	1,512
Total liabilities	876,873	896,828
EMEA [Member]
Assets [Abstract]
Contracted concessional assets	4,213,323	3,859,454
Investments carried under the equity method	55,784	55,009
Current financial investments	31,263	29,158
Cash and cash equivalents (project companies)	329,078	246,671
Total assets	4,629,448	4,190,291
Liabilities [Abstract]
Long-term and short-term project debt	2,778,043	2,564,290
Grants and other liabilities	42,202	35,230
Total liabilities	2,820,245	2,599,520
Allocated [Member]
Assets [Abstract]
Contracted concessional assets	9,084,270	8,924,272
Investments carried under the equity method	55,784	55,009
Current financial investments	207,545	228,038
Cash and cash equivalents (project companies)	520,862	472,656
Total assets	9,868,461	9,679,975
Liabilities [Abstract]
Long-term and short-term project debt	5,475,208	5,330,467
Grants and other liabilities	1,636,060	1,612,045
Total liabilities	7,111,268	6,942,512
Unallocated [Member]
Assets [Abstract]
Other non-current assets	210,378	272,664
Other current assets (including cash and cash equivalents at holding company level)	413,500	345,160
Total assets	623,878	617,824
Liabilities [Abstract]
Long-term and short-term corporate debt	643,083	668,201
Other non-current liabilities	657,345	546,053
Other current liabilities	185,190	181,922
Total liabilities	1,485,618	1,396,176
Equity	1,895,453	1,959,111
Total liabilities and equity	$ 3,381,071	$ 3,355,287

Financial information by segm63

Financial information by segment, Assets and liabilities by business sectors (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets [Abstract]
Contracted concessional assets	$ 9,084,270	$ 8,924,272
Investments carried under the equity method	55,784	55,009	$ 56,181
Current financial investments	210,138	228,038
Cash and cash equivalents (project companies)	669,387	594,811	514,712	$ 354,154
Total assets	10,492,339	10,297,799
Liabilities [Abstract]
Long-term and short-term project debt	5,475,208	5,330,467	5,470,669
Grants and other liabilities	1,636,060	1,612,045
Long-term and short-term corporate debt	643,083	668,201
Total liabilities	8,596,886	8,338,688
Equity	1,895,453	1,959,111	$ 2,023,501	$ 1,839,631
Total liabilities and equity	10,492,339	10,297,799
Renewable Energy [Member]
Assets [Abstract]
Contracted concessional assets	7,436,362	7,255,308
Investments carried under the equity method	12,419	12,953
Current financial investments	17,249	13,661
Cash and cash equivalents (project companies)	452,792	420,215
Total assets	7,918,822	7,702,137
Liabilities [Abstract]
Long-term and short-term project debt	4,162,596	3,979,096
Grants and other liabilities	1,635,508	1,611,067
Total liabilities	5,798,104	5,590,163
Efficient Natural Gas [Member]
Assets [Abstract]
Contracted concessional assets	660,387	646,927
Investments carried under the equity method	0	0
Current financial investments	116,430	136,644
Cash and cash equivalents (project companies)	39,064	30,295
Total assets	815,881	813,866
Liabilities [Abstract]
Long-term and short-term project debt	579,173	598,256
Grants and other liabilities	552	239
Total liabilities	579,725	598,495
Electric Transmission [Member]
Assets [Abstract]
Contracted concessional assets	897,269	929,005
Investments carried under the equity method	0	0
Current financial investments	59,289	62,215
Cash and cash equivalents (project companies)	15,325	11,357
Total assets	971,883	1,002,577
Liabilities [Abstract]
Long-term and short-term project debt	698,346	711,517
Grants and other liabilities	0	739
Total liabilities	698,346	712,256
Water [Member]
Assets [Abstract]
Contracted concessional assets	90,252	93,032
Investments carried under the equity method	43,365	42,056
Current financial investments	14,577	15,518
Cash and cash equivalents (project companies)	13,681	10,789
Total assets	161,875	161,395
Liabilities [Abstract]
Long-term and short-term project debt	35,093	41,598
Grants and other liabilities	0	0
Total liabilities	35,093	41,598
Allocated [Member]
Assets [Abstract]
Contracted concessional assets	9,084,270	8,924,272
Investments carried under the equity method	55,784	55,009
Current financial investments	207,545	228,038
Cash and cash equivalents (project companies)	520,862	472,656
Total assets	9,868,461	9,679,975
Liabilities [Abstract]
Long-term and short-term project debt	5,475,208	5,330,467
Grants and other liabilities	1,636,060	1,612,045
Total liabilities	7,111,268	6,942,512
Unallocated [Member]
Assets [Abstract]
Other non-current assets	210,378	272,664
Other current assets (including cash and cash equivalents at holding company level)	413,500	345,160
Total assets	623,878	617,824
Liabilities [Abstract]
Long-term and short-term corporate debt	643,083	668,201
Other non-current liabilities	657,345	546,053
Other current liabilities	185,190	181,922
Total liabilities	1,485,618	1,396,176
Equity	1,895,453	1,959,111
Total liabilities and equity	$ 3,381,071	$ 3,355,287

Financial information by segm64

Financial information by segment, Depreciation, amortization and impairment charges recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial information by segment [Abstract]
Depreciation, amortization, and impairment charges	$ (310,960)	$ (332,925)	$ (261,301)
Renewable Energy [Member]
Financial information by segment [Abstract]
Depreciation, amortization, and impairment charges	(282,376)	(304,235)	(232,699)
Electric Transmission [Member]
Financial information by segment [Abstract]
Depreciation, amortization, and impairment charges	(28,584)	(28,690)	(28,602)
North America [Member]
Financial information by segment [Abstract]
Depreciation, amortization, and impairment charges	(123,726)	(129,478)	(129,091)
South America [Member]
Financial information by segment [Abstract]
Depreciation, amortization, and impairment charges	(40,880)	(62,387)	(41,274)
EMEA [Member]
Financial information by segment [Abstract]
Depreciation, amortization, and impairment charges	$ (146,354)	$ (141,060)	$ (90,936)

Changes in the scope of the c65

Changes in the scope of the consolidated financial statements, Changes (Details) - USD ($) $ in Thousands		Jan. 07, 2016	Dec. 31, 2017	Dec. 31, 2016	Feb. 28, 2017	Aug. 03, 2016
Changes in the scope of the consolidated financial statements [Abstract]
Percentage interest acquired					12.50%
Solacor 1/2 [Member]
Changes in the scope of the consolidated financial statements [Abstract]
Percentage interest acquired		13.00%		13.00%
Ownership interest	[1]		87.00%
Purchase price		$ 19,923
Seville PV [Member]
Changes in the scope of the consolidated financial statements [Abstract]
Percentage interest acquired				80.00%		80.00%
Ownership interest	[2]		80.00%
Purchase price						$ 3,214
JGC [Member] | Solacor 1/2 [Member]
Changes in the scope of the consolidated financial statements [Abstract]
Ownership interest		13.00%		13.00%
[1]	JGC, a Japanese engineering company, holds 13% of the shares in each of Solacor 1 and Solacor 2.
[2]	Instituto para la Diversificacion y Ahorro de la Energia ("Idae"), a Spanish state owned company, holds 20% of the shares in Seville PV.

Contracted concessional asset66

Contracted concessional assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Movements of Contracted Concessional Assets [Abstract]
Contracted concessional financial assets	$ 1,169,216	$ 1,100,243
Total, beginning of period	8,924,272
Total, end of period	9,084,270	8,924,272
Cost [Member]
Movements of Contracted Concessional Assets [Abstract]
Total, beginning of period	10,067,596	10,126,023
Additions	15,426	6,346
Subtractions	(42,500)
Translation differences	593,247	(68,199)
Change in the scope of the consolidated financial statements		5,876
Reclassification and other movements		(2,450)
Total, end of period	10,633,769	10,067,596
Accumulated Amortization [Member]
Movements of Contracted Concessional Assets [Abstract]
Total, beginning of period	(1,143,324)	(825,126)
Additions	(309,846)	(332,925)
Translation differences	(96,329)	17,108
Change in the scope of the consolidated financial statements		(2,381)
Total, end of period	(1,549,499)	(1,143,324)
Contracted Concessional Assets [Member]
Movements of Contracted Concessional Assets [Abstract]
Contracted concessional financial assets	936,004	$ 928,720
Impairment loss	$ 0
Palmatir and Cadonal [Member]
Movements of Contracted Concessional Assets [Abstract]
Assumed percentage decrease in generation		5.00%
Assumed percentage increase in discount rate		0.50%
Palmatir and Cadonal [Member] | Bottom of Range [Member]
Movements of Contracted Concessional Assets [Abstract]
Discount rate		6.70%
Palmatir and Cadonal [Member] | Top of Range [Member]
Movements of Contracted Concessional Assets [Abstract]
Discount rate		7.00%
Cadonal [Member]
Movements of Contracted Concessional Assets [Abstract]
Impairment loss		$ 17,299
Recoverable amount of impairment loss		91,795
Additional impairment loss that could be recognised due to assumed percentage decrease in generation		5,000
Additional impairment loss that could be recognised due to assumed increase in discount rate		3,000
Palmatir [Member]
Movements of Contracted Concessional Assets [Abstract]
Impairment loss		3,101
Recoverable amount of impairment loss		123,912
Additional impairment loss that could be recognised due to assumed percentage decrease in generation		7,000
Additional impairment loss that could be recognised due to assumed increase in discount rate		$ 4,000
Solana [Member]
Movements of Contracted Concessional Assets [Abstract]
Assumed percentage decrease in generation	5.00%	5.00%
Additional impairment loss that could be recognised due to assumed percentage decrease in generation		$ 40,000
Assumed percentage increase in discount rate	0.50%	0.50%
Additional impairment loss that could be recognised due to assumed increase in discount rate		$ 30,000
Percentage recoverable amount exceeds carrying amount	7.00%	3.00%
Solana [Member] | Bottom of Range [Member]
Movements of Contracted Concessional Assets [Abstract]
Discount rate	4.70%	4.10%
Solana [Member] | Top of Range [Member]
Movements of Contracted Concessional Assets [Abstract]
Discount rate	5.00%	5.10%

Investments carried under the67

Investments carried under the equity method, Movement of the investments held in associates (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Investments in associates [Abstract]
Initial balance	$ 55,009	$ 56,181
Share of (loss)/profit	5,351	6,646
Dividend distribution	(2,454)	(3,954)
Equity distribution	(549)	(3,099)
Currency translation differences	(1,573)	(765)
Final balance	$ 55,784	$ 55,009

Investments carried under the68

Investments carried under the equity method, Breakdown of stand-alone amounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments in associates [Abstract]
Non-current assets		$ 9,350,432	$ 9,251,945
Current assets		1,141,907	1,045,854
Non-current liabilities		8,096,498	7,163,622
Current liabilities		500,388	1,175,066
Revenue		1,008,381	971,797	$ 790,881
Profit/(loss) for the year		(104,887)	1,667	(198,186)
Investment under the equity method		55,784	55,009	$ 56,181
Share of profit		$ 5,351	$ 6,646
Evacuacion Valdecaballeros, S.L. [Member]
Investments in associates [Abstract]
% Shares		57.16%	57.16%
Non-current assets		$ 21,306	$ 19,283
Current assets		841	931
Non-current liabilities		373	306
Current liabilities		451	532
Revenue		298	537
Operating profit/(loss)		(708)	(545)
Profit/(loss) for the year		(730)	(565)
Investment under the equity method		$ 9,175	$ 9,528
Evacuacion Valdecaballeros, S.L. [Member] | Bottom of Range [Member]
Investments in associates [Abstract]
Percentage of shareholders required for approval of relevant decisions		75.00%
Myah Bahr Honaine, S.P.A. [Member]
Investments in associates [Abstract]
% Shares	[1]	25.50%	25.50%
Non-current assets	[1]	$ 195,275	$ 202,150
Current assets	[1]	64,114	67,120
Non-current liabilities	[1]	91,205	104,704
Current liabilities	[1]	12,649	14,158
Revenue	[1]	46,767	52,770
Operating profit/(loss)	[1]	28,468	34,247
Profit/(loss) for the year	[1]	24,464	29,990
Investment under the equity method	[1]	$ 43,365	42,056
Myah Bahr Honaine, S.P.A. [Member] | Geida Tlemcen, S.L. [Member]
Investments in associates [Abstract]
Ownership interest		51.00%
Share of profit		$ 6,238	$ 7,647
Pectonex, R.F. Proprietary Limited [Member]
Investments in associates [Abstract]
% Shares		50.00%	50.00%
Non-current assets		$ 3,904	$ 3,730
Current assets		0	0
Non-current liabilities		0	0
Current liabilities		2	1
Revenue		0	0
Operating profit/(loss)		(206)	(187)
Profit/(loss) for the year		(206)	(187)
Investment under the equity method		$ 3,244	$ 3,425
Evacuacion Villanueva del Rey, S.L [Member]
Investments in associates [Abstract]
% Shares		40.02%	40.02%
Non-current assets		$ 3,526	$ 3,251
Current assets		53	17
Non-current liabilities		2,265	2,118
Current liabilities		190	142
Revenue		0	0
Operating profit/(loss)		37	31
Profit/(loss) for the year		0	0
Investment under the equity method		0	0
Associate Companies [Member]
Investments in associates [Abstract]
Non-current assets		240,011	228,684
Current assets		65,008	68,068
Non-current liabilities		93,843	107,128
Current liabilities		13,292	14,833
Revenue		47,065	53,307
Operating profit/(loss)		27,591	33,546
Profit/(loss) for the year		23,528	29,238
Investment under the equity method		$ 55,784	$ 55,009
[1]	Myah Bahr Honaine, S.P.A., the project entity, is 51% owned by Geida Tlemcen, S.L. which is accounted for using the equity method in these consolidated financial statements. Share of profit of Myah Bahr Honaine S.P.A. included in these consolidated financial statements amounts to $6,238 thousand in 2017 and $7,647 thousand in 2016.

Financial instruments by cate69

Financial instruments by category, Reconciliation to statement of financial position (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial Assets [Abstract]
Derivative assets	$ 8,230	$ 3,822
Investment in Ten West Link	2,088
Abengoa debt and Equity instruments	1,715
Preferred equity in ACBH		30,488
Other financial investments	243,347	263,501
Clients and other receivables	244,449	207,621
Cash and cash equivalents	669,387	594,811	$ 514,712	$ 354,154
Total financial assets	1,169,216	1,100,243
Financial Liabilities [Abstract]
Corporate debt	643,083	668,201
Project debt	5,475,208	5,330,467	$ 5,470,669
Related parties - non-current	141,031	101,750
Trade and other current liabilities	155,144	160,505
Derivative liabilities	329,731	349,266
Total financial liabilities	6,744,197	6,610,189
Hedging Derivatives [Member]
Financial Liabilities [Abstract]
Corporate debt	0	0
Project debt	0	0
Related parties - non-current	0	0
Trade and other current liabilities	0	0
Derivative liabilities	329,731	349,266
Total financial liabilities	329,731	349,266
Hedging Derivatives [Member]
Financial Assets [Abstract]
Derivative assets	8,230	3,822
Investment in Ten West Link	0
Abengoa debt and Equity instruments	0
Preferred equity in ACBH		0
Other financial investments	0	0
Clients and other receivables	0	0
Cash and cash equivalents	0	0
Total financial assets	8,230	3,822
Payables [Member]
Financial Liabilities [Abstract]
Corporate debt	643,083	668,201
Project debt	5,475,208	5,330,467
Related parties - non-current	141,031	101,750
Trade and other current liabilities	155,144	160,505
Derivative liabilities	0	0
Total financial liabilities	6,414,466	6,260,923
Loans and Receivables [Member]
Financial Assets [Abstract]
Derivative assets	0	0
Investment in Ten West Link	2,088
Abengoa debt and Equity instruments	0
Preferred equity in ACBH		0
Other financial investments	243,347	263,501
Clients and other receivables	244,449	207,621
Cash and cash equivalents	669,387	594,811
Total financial assets	1,159,271	1,065,933
Available for Sale Financial Assets [Member]
Financial Assets [Abstract]
Derivative assets	0	0
Investment in Ten West Link	0
Abengoa debt and Equity instruments	1,715
Preferred equity in ACBH		30,488
Other financial investments	0	0
Clients and other receivables	0	0
Cash and cash equivalents	0	0
Total financial assets	$ 1,715	$ 30,488

Financial instruments by cate70

Financial instruments by category, Restructuring agreement of Abengoa (Details) $ in Millions	Mar. 31, 2017USD ($)	Mar. 15, 2017USD ($)	Feb. 28, 2017mi	Feb. 24, 2017USD ($)	Apr. 30, 2017USD ($)	Dec. 31, 2017USD ($)mi	Dec. 31, 2014
Restructuring agreement of Abengoa [Abstract]
Dividends retained from Abengoa				$ 10.4
Percentage interest acquired			12.50%
Length of transmission lines | mi			114
New Money Tradable Notes [Member]
Restructuring agreement of Abengoa [Abstract]
Restructuring agreement assigned tradable notes amount	$ 44.5
Restructuring agreement cash contribution in exchange of tradable notes	$ 43.6
Ten West Link [Member]
Restructuring agreement of Abengoa [Abstract]
Percentage interest acquired						12.50%
Length of transmission lines | mi						114
Abengoa [Member]
Restructuring agreement of Abengoa [Abstract]
Corporate tradable bonds issued period						5 years 6 months
Corporate tradable bonds issued extendable period						2 years
Corporate tradable bonds interest rate	1.50%
Corporate tradable bonds interest rate paid in cash	0.25%
Corporate tradable bonds interest rate paid in kind	1.25%
Loss from derecognition of fair value assigned to preferred equity investment and recognition of debt and equity instruments						$ 5.8
Profit resulting from sale of major part of debt and equity instruments						$ 6.5
Dividends retained from Abengoa		$ 10.4
Percentage interest acquired							64.28%
Abengoa [Member] | New Money Tradable Notes [Member]
Restructuring agreement of Abengoa [Abstract]
Proceeds from sale of tradable notes					$ 44.9

Derivative financial instrume71

Derivative financial instruments, Breakdown of fair value amounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Currency Swap [Member]
Breakdown of fair value amount of derivative financial instruments [Abstract]
Term of agreement	5 years
Interest Rate Derivatives [Member] | Cash Flow Hedge [Member]
Breakdown of fair value amount of derivative financial instruments [Abstract]
Assets	$ 8,230	$ 3,822
Liabilities	$ 329,731	$ 349,266

Derivative financial instrume72

Derivative financial instruments, Breakdown of maturities of notional and fair value amounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Loss on cash flow hedges	$ 70,953	$ 72,774	$ 55,841
Cap [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	756,339	478,314
Fair value	$ 8,230	$ 3,822
Cap [Member] | Up to 1 Year [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	42,324	24,261
Fair value	$ 347	$ 250
Cap [Member] | Between 1 and 2 Years [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	45,422	25,934
Fair value	$ 978	$ 262
Cap [Member] | Between 2 and 3 Years [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	48,215	27,880
Fair value	$ 396	$ 275
Cap [Member] | Subsequent Years [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	620,378	400,239
Fair value	$ 6,509	$ 3,035
Swap [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	2,231,611	1,860,355
Fair value	$ (329,731)	$ (349,266)
Swap [Member] | Up to 1 Year [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	139,939	75,837
Fair value	$ (13,224)	$ (12,383)
Swap [Member] | Between 1 and 2 Years [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	94,285	199,832
Fair value	$ (14,378)	$ (14,927)
Swap [Member] | Between 2 and 3 Years [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	103,536	83,897
Fair value	$ (15,923)	$ (13,957)
Swap [Member] | Subsequent Years [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Notionals	1,893,850	1,500,789
Fair value	$ (286,206)	$ (307,999)
Interest Rate Derivatives [Member] | Euros [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Maturity date	2,030
Interest Rate Derivatives [Member] | Euros [Member] | Bottom of Range [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Percentage of notional amount of project debt hedged	87.00%
Average guaranteed interest rates	3.20%
Interest Rate Derivatives [Member] | Euros [Member] | Top of Range [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Percentage of notional amount of project debt hedged	100.00%
Average guaranteed interest rates	4.87%
Interest Rate Derivatives [Member] | U.S. Dollars [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Maturity date	2,032
Interest Rate Derivatives [Member] | U.S. Dollars [Member] | Bottom of Range [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Percentage of notional amount of project debt hedged	70.00%
Average guaranteed interest rates	2.32%
Interest Rate Derivatives [Member] | U.S. Dollars [Member] | Top of Range [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Percentage of notional amount of project debt hedged	100.00%
Average guaranteed interest rates	5.27%
Interest Rate Derivatives [Member] | Cash Flow Hedge [Member]
Breakdown of Maturities of Notional and Fair Value Amounts [Abstract]
Loss on cash flow hedges	$ (70,953)	(72,774)	(55,841)
Gain (loss) on net amount of time value component	860	1,694	$ 4,234
After-tax result accumulated in equity	$ 80,968	$ 52,797

Related parties (Details)

Related parties (Details) $ in Thousands, € in Millions	Nov. 30, 2017USD ($)	Feb. 24, 2017USD ($)	Sep. 30, 2017EUR (€)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Details of Balances [Abstract]
Current receivables with related parties				$ 11,567	$ 12,031
Non-current receivables with related parties				2,108	30,505
Current payables with related parties				63,409	61,338
Non-current payables with related parties				141,031	101,750
Receivables from related parties				1,715
Preferred equity in ACBH					30,488
Transactions With Related Party [Abstract]
Financial income				1,007	3,298	$ 3,464
Financial expenses				(463,717)	(408,007)	(333,921)
Dividends retained from Abengoa		$ 10,400
Related Parties [Member]
Details of Balances [Abstract]
Receivables from related parties				1,715
Preferred equity in ACBH					30,488
Transactions With Related Party [Abstract]
Dividends retained from Abengoa				10,400	28,000
Income for cancellation of subordinated debt					7,600
Income for discounts received for prepayment of payables					1,700
Subsidiaries [Member]
Transactions With Related Party [Abstract]
Sales				0	0	44,260
Services rendered				3,495	1,220	523
Services received				(114,416)	(115,779)	(106,737)
Financial income				74	60	1,466
Financial expenses				$ (1,154)	$ (2,460)	$ (1,968)
Abengoa [Member]
Transactions With Related Party [Abstract]
Term to maintain guarantees and letters of credit				5 years
Guarantees amount				$ 31,500
Other existing debts receivables | €			€ 7.8
Guarantees amount replaced				$ 112,000
Abengoa [Member] | Solana [Member]
Transactions With Related Party [Abstract]
Performance consideration receivable	$ 120,000
Performance obligations proceeds applied to project debt	80,000
Performance obligations proceeds applied to additional plant repairs	25,000
Other obligations	15,000
Other obligations per semester	6,500
Recognition period of other contingnt obligations considered				10 years
Performance obligations proceeds received from Abengoa	$ 42,500
Abengoa [Member] | Solana and Mojave [Member]
Transactions With Related Party [Abstract]
Minimum ownership requirement percentage	16.00%

Clients and other receivable (D

Clients and other receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Clients and other receivables [Abstract]
Trade receivables	$ 186,728	$ 151,199
Tax receivables	39,607	29,705
Prepayments	6,375	10,261
Other accounts receivable	11,739	16,456
Clients and other receivables	244,449	207,621
Up to 3 Months [Member]
Clients and other receivables [Abstract]
Trade receivables	186,728	151,199
Euros [Member]
Clients and other receivables [Abstract]
Trade receivables	109,165	98,798
Rand [Member]
Clients and other receivables [Abstract]
Trade receivables	23,792	12,807
Other [Member]
Clients and other receivables [Abstract]
Trade receivables	7,363	7,151
All Foreign Currencies [Member]
Clients and other receivables [Abstract]
Trade receivables	$ 140,320	$ 118,756

Cash and cash equivalents (Deta

Cash and cash equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and cash equivalents [abstract]
Cash and cash equivalents	$ 669,387	$ 594,811	$ 514,712	$ 354,154
Cash held to satisfy the requirements of non-recourse debt agreements	263,000
U.S. Dollar [Member]
Cash and cash equivalents [abstract]
Cash and cash equivalents	319,400	343,954
Euro [Member]
Cash and cash equivalents [abstract]
Cash and cash equivalents	288,625	196,382
Algerian Dinar [Member]
Cash and cash equivalents [abstract]
Cash and cash equivalents	13,628	10,736
South African Rand [Member]
Cash and cash equivalents [abstract]
Cash and cash equivalents	40,999	39,689
Others [Member]
Cash and cash equivalents [abstract]
Cash and cash equivalents	$ 6,735	$ 4,050

Equity (Details)

Equity (Details) $ / shares in Units, $ in Thousands

Nov. 13, 2017$ / shares

Aug. 03, 2017$ / shares

May 15, 2017$ / shares

Mar. 15, 2017USD ($)

Feb. 27, 2017$ / shares

Feb. 24, 2017USD ($)

Jul. 14, 2015shares

May 14, 2015$ / sharesshares

Jan. 22, 2015USD ($)$ / sharesshares

Jun. 18, 2014USD ($)$ / sharesshares

Jan. 21, 2015

Jul. 13, 2015

Dec. 31, 2017USD ($)Vote$ / sharesshares

Dec. 31, 2016USD ($)

Equity [Abstract]

Number of shares sold (in shares) | shares

20,217,260

24,850,000

Share price (in dollars per share) | $ / shares

$ 33.14

$ 29

Proceeds from issuing shares

$ 720,650

Share capital

2,485

$ 10,022

$ 10,022

Additional paid in capital

$ 682,810

Discount percentage applied to share price

3.00%

Shares outstanding (in shares) | shares

100,217,260

Nominal value per share (in dollars per share) | $ / shares

$ 0.10

Voting right per share | Vote

1

Dividends retained from Abengoa

$ 10,400

Treasury shares held (in shares) | shares

0

Increase (decrease) in treasury shares (in shares) | shares

0

First Quarter [Member]

Equity [Abstract]

Dividend declared and paid (in dollars per share) | $ / shares

$ 0.25

Second Quarter [Member]

Equity [Abstract]

Dividend declared and paid (in dollars per share) | $ / shares

$ 0.26

Third Quarter [Member]

Equity [Abstract]

Dividend declared and paid (in dollars per share) | $ / shares

$ 0.29

Fourth Quarter [Member]

Equity [Abstract]

Dividend declared and paid (in dollars per share) | $ / shares

$ 0.25

Abengoa [Member]

Equity [Abstract]

Number of shares sold (in shares) | shares

2,000,000

10,580,000

Share price (in dollars per share) | $ / shares

$ 31

Proceeds from issuing shares

$ 327,980

Ownership interest

64.30%

51.10%

49.10%

Percent of newly-issued shares subscribed

51.00%

Dividends retained from Abengoa

$ 10,400

Exchangeable Notes [Member] | Abengoa [Member]

Equity [Abstract]

Ownership interest

41.47%

Number of shares issued upon conversion of exchangeable notes (in shares) | shares

7,595,639

Principal amount

$ 279,000

Subsidiary of Abengoa [Member]

Equity [Abstract]

Shares purchased by underwriters (in shares) | shares

3,727,500

Total proceeds from offering

$ 828,748

Corporate debt, Breakdown of co

Corporate debt, Breakdown of corporate debt (Details) $ in Thousands, € in Millions	Feb. 10, 2017USD ($)Swap	Dec. 31, 2017USD ($)	Feb. 10, 2017EUR (€)	Dec. 31, 2016USD ($)
Corporate debt [Abstract]
Total Non-Current		$ 574,176		$ 376,340
Total Current		68,907		291,861
Credit Facilities with Financial Entities [Member]
Corporate debt [Abstract]
Total Non-Current		320,783		123,804
Total Current		65,833		289,035
Notes and Bonds [Member]
Corporate debt [Abstract]
Total Non-Current		253,393		252,536
Total Current		$ 3,074		$ 2,826
Note Issuance Facility [Member]
Corporate debt [Abstract]
Principal amount	$ 330,000		€ 275
Number of interest rate swaps | Swap	2
Fixed interest rate	5.50%		5.50%
Note Issuance Facility [Member] | EURIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate	4.90%		4.90%
Series 1 Notes [Member]
Corporate debt [Abstract]
Maturity date		2,022
Series 2 Notes [Member]
Corporate debt [Abstract]
Maturity date		2,023
Series 3 Notes [Member]
Corporate debt [Abstract]
Maturity date		2,024

Corporate debt, Details of corp

Corporate debt, Details of corporate debt (Details) $ in Thousands, € in Millions	Dec. 27, 2017USD ($)	Sep. 25, 2017USD ($)	Dec. 22, 2014USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Jul. 20, 2017USD ($)	Jul. 20, 2017EUR (€)	Jun. 26, 2015USD ($)	Dec. 03, 2014USD ($)	Nov. 17, 2014USD ($)
Corporate debt [Abstract]
Proceeds from corporate debt				$ 296,398	$ 11,113	$ 459,366
Repayment of debt				613,242	182,636	175,389
Short-term corporate debt				68,907	291,861
Long-term corporate debt				$ 574,176	376,340
Federal Funds Rate [Member]
Corporate debt [Abstract]
Adjustment to interest rate									0.50%
LIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate									1.00%
2019 Notes [Member]
Corporate debt [Abstract]
Principal amount											$ 255,000
Fixed interest rate											7.00%
Maturity date				November 15, 2019
Credit Facility Tranche A [Member]
Corporate debt [Abstract]
Fixed interest rate										4.70%
Maturity date				December 24, 2018
Proceeds from corporate debt			$ 125,000
Repayment of debt	$ 63,000	$ 8,000
Short-term corporate debt				$ 54,000
Long-term corporate debt					54,000
Credit Facility Tranche A [Member] | Top of Range [Member]
Corporate debt [Abstract]
Principal amount										$ 125,000
Tranche A Eurodollar Rate Loans [Member] | LIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate										2.75%
Tranche A Base Rate Loans [Member]
Corporate debt [Abstract]
Adjustment to interest rate										1.75%
Tranche A Base Rate Loans [Member] | Federal Funds Rate [Member]
Corporate debt [Abstract]
Adjustment to interest rate										0.50%
Tranche A Base Rate Loans [Member] | LIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate										1.00%
Credit Facility Tranche B [Member]
Corporate debt [Abstract]
Principal amount									$ 290,000
Maturity date				December 2,017
Short-term corporate debt					$ 288,317
Long-term corporate debt						$ 288,317
Tranche B Eurodollar Rate Loans [Member] | LIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate									2.50%
Tranche B Base Rate Loans [Member] | LIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate									1.50%
Credit Facility 2017 [Member]
Corporate debt [Abstract]
Principal amount							$ 11,900
Maturity date				July 20, 2018
Credit Facility 2017 [Member] | Top of Range [Member]
Corporate debt [Abstract]
Principal amount | €								€ 10
Credit Facility 2017 [Member] | EURIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate							2.25%	2.25%
Credit Facility 2017 [Member] | LIBOR [Member]
Corporate debt [Abstract]
Adjustment to interest rate							2.25%	2.25%

Corporate debt, Repayment sched

Corporate debt, Repayment schedule (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Repayment schedule [Abstract]
Corporate debt	$ 643,083	$ 668,201
2018 [Member]
Repayment schedule [Abstract]
Corporate debt	68,907
2019 [Member]
Repayment schedule [Abstract]
Corporate debt	253,393
2020 [Member]
Repayment schedule [Abstract]
Corporate debt	0
2021 [Member]
Repayment schedule [Abstract]
Corporate debt	0
2022 [Member]
Repayment schedule [Abstract]
Corporate debt	107,316
Subsequent Years [Member]
Repayment schedule [Abstract]
Corporate debt	213,467	$ 0
Credit Facility Tranche A [Member]
Repayment schedule [Abstract]
Corporate debt	53,778
Credit Facility Tranche A [Member] | 2018 [Member]
Repayment schedule [Abstract]
Corporate debt	53,778
Credit Facility Tranche A [Member] | 2019 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility Tranche A [Member] | 2020 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility Tranche A [Member] | 2021 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility Tranche A [Member] | 2022 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility Tranche A [Member] | Subsequent Years [Member]
Repayment schedule [Abstract]
Corporate debt	0
Note Issuance Facility [Member]
Repayment schedule [Abstract]
Corporate debt	320,890
Note Issuance Facility [Member] | 2018 [Member]
Repayment schedule [Abstract]
Corporate debt	107
Note Issuance Facility [Member] | 2019 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Note Issuance Facility [Member] | 2020 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Note Issuance Facility [Member] | 2021 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Note Issuance Facility [Member] | 2022 [Member]
Repayment schedule [Abstract]
Corporate debt	107,316
Note Issuance Facility [Member] | Subsequent Years [Member]
Repayment schedule [Abstract]
Corporate debt	213,467
Credit Facility 2017 [Member]
Repayment schedule [Abstract]
Corporate debt	11,948
Credit Facility 2017 [Member] | 2018 [Member]
Repayment schedule [Abstract]
Corporate debt	11,948
Credit Facility 2017 [Member] | 2019 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility 2017 [Member] | 2020 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility 2017 [Member] | 2021 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility 2017 [Member] | 2022 [Member]
Repayment schedule [Abstract]
Corporate debt	0
Credit Facility 2017 [Member] | Subsequent Years [Member]
Repayment schedule [Abstract]
Corporate debt	0
2019 Notes [Member]
Repayment schedule [Abstract]
Corporate debt	256,467
2019 Notes [Member] | 2018 [Member]
Repayment schedule [Abstract]
Corporate debt	3,074
2019 Notes [Member] | 2019 [Member]
Repayment schedule [Abstract]
Corporate debt	253,393
2019 Notes [Member] | 2020 [Member]
Repayment schedule [Abstract]
Corporate debt	0
2019 Notes [Member] | 2021 [Member]
Repayment schedule [Abstract]
Corporate debt	0
2019 Notes [Member] | 2022 [Member]
Repayment schedule [Abstract]
Corporate debt	0
2019 Notes [Member] | Subsequent Years [Member]
Repayment schedule [Abstract]
Corporate debt	$ 0

Corporate debt, Movement in cor

Corporate debt, Movement in corporate debt, split between cash and non-cash items (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Corporate debt [Abstract]
Beginning balance	$ 668,201
Cash flow	(68,372)
Non-cash changes	43,254
Ending balance	$ 643,083

Project debt, Movements of proj

Project debt, Movements of project debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Project Debt - Long Term [Abstract]
Beginning balance	$ 4,629,184	$ 3,574,464
Increases	52,027	36,842
Decreases	(42,560)	0
Currency translation differences	316,646	(64,426)
Reclassifications	273,620	1,082,304
Ending balance	5,228,917	4,629,184
Project Debt - Short Term [Abstract]
Beginning balance	701,283	1,896,205
Increases	304,707	329,434
Decreases	(509,131)	(480,969)
Currency translation differences	23,052	38,917
Reclassifications	(273,620)	(1,082,304)
Ending balance	246,291	701,283
Total Project Debt [Abstract]
Beginning balance	5,330,467	5,470,669
Increases	356,734	366,276
Decreases	(551,691)	(480,969)
Currency translation differences	339,698	(25,509)
Reclassifications	0	0
Ending balance	$ 5,475,208	$ 5,330,467

Project debt, Repayment schedul

Project debt, Repayment schedule (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Repayment schedule [Abstract]
Project debt	$ 5,475,208	$ 5,330,467	$ 5,470,669
2018 [Member]
Repayment schedule [Abstract]
Interest repayment	21,612
Nominal repayment	224,679
2019 [Member]
Repayment schedule [Abstract]
Project debt	246,471
2020 [Member]
Repayment schedule [Abstract]
Project debt	265,002
2021 [Member]
Repayment schedule [Abstract]
Project debt	280,303
2022 [Member]
Repayment schedule [Abstract]
Project debt	313,559
Subsequent Years [Member]
Repayment schedule [Abstract]
Project debt	$ 4,123,582

Project debt, movement in proje

Project debt, movement in project debt, split between cash and non-cash items (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Project debt [Abstract]
Beginning balance	$ 5,330,467
Cash flow	(248,472)
Non-cash changes	393,212
Ending balance	$ 5,475,208

Project debt, Movement in pro84

Project debt, Movement in project debt and Significant foreign currency denominated debts (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Project Debt [Abstract]
Project debt	$ 5,475,208	$ 5,330,467	$ 5,470,669
Euro [Member]
Project Debt [Abstract]
Project debt	2,286,771	2,102,985
Algerian Dinar [Member]
Project Debt [Abstract]
Project debt	35,093	41,598
Rand [Member]
Project Debt [Abstract]
Project debt	456,179	419,708
All Foreign Currencies [Member]
Project Debt [Abstract]
Project debt	$ 2,778,043	$ 2,564,291

Grants and other liabilities (D

Grants and other liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Type	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Oct. 02, 2013USD ($)
Grants and other liabilities [Abstract]
Grants	$ 1,225,877	$ 1,297,755
Number of grant types | Type	2
Other liabilities	$ 410,183	314,290
Grant and other non-current liabilities	1,636,060	1,612,045
Income from grants	59,707	59,085	$ 67,859
Solana and Mojave [Member]
Grants and other liabilities [Abstract]
Income from grants	59,800	57,000
U.S. Department of Treasury [Member]
Grants and other liabilities [Abstract]
Grants	771,000	803,000
Federal Financing Bank [Member]
Grants and other liabilities [Abstract]
Grants	452,000	492,000
Liberty Interactive Corporation [Member]
Grants and other liabilities [Abstract]
Grant and other non-current liabilities	$ 352,000	$ 263,000
Class A membership investment				$ 300,000

Trade payables and other curr86

Trade payables and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Trade payables and other current liabilities [Abstract]
Trade accounts payables	$ 107,662	$ 121,527
Down payments from clients	6,466	6,153
Suppliers of concessional assets current	236	380
Liberty (see Note 16)	0	21,461
Other accounts payable	40,780	10,984
Total	$ 155,144	$ 160,505

Income Tax, Analysis of deferre

Income Tax, Analysis of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Tax Assets and Liabilities [Abstract]
Net operating losses		$ 387,000
Corporate tax rate		35.00%
Deferred tax assets		$ 165,136	$ 202,891	$ 191,314
Deferred tax liabilities		186,583	95,037	$ 79,654
Plan [Member]
Deferred Tax Assets and Liabilities [Abstract]
Corporate tax rate	21.00%
Net tax credits for Operating losses carryforwards [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		71,219	102,804
Temporary differences derivatives financial instruments [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		93,719	99,930
Temporary differences derivatives financial instruments [Member] | Solar Plants in Spain [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		69,000
Temporary differences derivatives financial instruments [Member] | ACT [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		18,000
Temporary differences tax/book amortization [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax liabilities		113,432	28,810
Temporary differences tax/book value of contracted concessional assets [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax liabilities		66,247	61,818
Other temporary differences [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax assets		198	157
Deferred tax liabilities		6,904	$ 4,409
Temporary difference for accelerated tax amortization [Member] | Solar Plants in Spain [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax liabilities		51,000
Temporary difference for accelerated tax amortization [Member] | Solana and Mojave [Member]
Deferred Tax Assets and Liabilities [Abstract]
Deferred tax liabilities		$ 63,000

Income Tax, Movements in deferr

Income Tax, Movements in deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets [Abstract]
Beginning of period	$ 202,891	$ 191,314
Increase/decrease through the consolidated income statement	(31,421)	16,033
Increase/decrease through other consolidated comprehensive income (equity)	(13,312)	(5,701)
Other movements	6,978	1,245
End of period	165,136	202,891
Deferred Tax Liabilities [Abstract]
Beginning of period	95,037	79,654
Increase/decrease through the consolidated income statement	86,418	16,681
Increase/decrease through other consolidated comprehensive income (equity)	0	(62)
Other movements	5,128	(1,236)
End of period	$ 186,583	$ 95,037

Income Tax, Income tax benefit_

Income Tax, Income tax benefit/(expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax [Abstract]
Current tax	$ (1,998)	$ (1,018)	$ (2,182)
Deferred tax	(117,839)	(648)	(21,608)
Deferred tax expense (income) relating to origination and reversal of temporary differences	(98,508)	(648)	(22,492)
Deferred tax expense (income) relating to changes in tax rates	(19,331)	0	884
Total income tax benefit/(expense)	$ (119,837)	$ (1,666)	$ (23,790)

Income Tax, Effective income ta

Income Tax, Effective income tax rate reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax [Abstract]
Consolidated income / (loss) before taxes	$ 14,950	$ 3,333	$ (174,396)
Average statutory tax rate	30.00%	30.00%	30.00%
Corporate income tax at average statutory tax rate	$ (4,485)	$ (1,000)	$ 52,319
Income tax of associates, net	1,765	2,110	2,341
Differences in foreign tax rates	3,304	(4,930)	(2,389)
Permanent differences	19,324	11,121	(19,456)
Incentives, deductions, and tax losses carryforwards	(20,994)	(11,110)	(58,039)
Change in corporate income tax	(19,331)	0	884
U.S Internal Revenue Code Section 382	(96,328)	0	0
Other non-taxable income/(expense)	(3,092)	2,143	550
Total income tax benefit/(expense)	$ (119,837)	$ (1,666)	$ (23,790)
Limitation imposed on net interest expense, that exceeds EBITDA	30.00%
Limitation imposed on net interest expense, that exceeds EBIT	30.00%
Limitation imposed on NOL arising in tax years on taxable income	80.00%
NOL applicable carry forward period	20 years
BEAT applies on entity that exceeds taxable income percentage	10.00%

Third-party guarantees and co91

Third-party guarantees and commitments (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Third-party Guarantees [Abstract]
Bank Bond and Surety Insurance deposited as guarantee			$ 32,428	$ 27,163
Issuance of guarantees previously issued by Abengoa		$ 112,000
Contractual Obligations [Abstract]
Corporate debt			643,083	668,201
Loans with credit institutions (project debt)	[1]		4,628,289	4,498,930
Notes and bonds (project debt)			846,919	831,538
Purchase commitments			3,149,813	2,894,146
Accrued interest estimate during the useful life of loans			3,129,321	3,356,750
2018 [Member]
Contractual Obligations [Abstract]
Corporate debt			68,907	291,861
Loans with credit institutions (project debt)	[1]		215,117	183,929
Notes and bonds (project debt)			31,174	27,225
Purchase commitments			141,867	136,032
Accrued interest estimate during the useful life of loans			340,481	332,408
2018/2019 and 2019/2020 [Member]
Contractual Obligations [Abstract]
Corporate debt			253,393	376,340
Loans with credit institutions (project debt)	[1]		457,853	388,679
Notes and bonds (project debt)			53,620	49,422
Purchase commitments			230,014	263,398
Accrued interest estimate during the useful life of loans			630,108	617,852
2020/2021 and 2021/2022 [Member]
Contractual Obligations [Abstract]
Corporate debt			107,316	0
Loans with credit institutions (project debt)	[1]		539,466	459,361
Notes and bonds (project debt)			54,395	48,740
Purchase commitments			259,845	246,904
Accrued interest estimate during the useful life of loans			559,856	543,927
Subsequent [Member]
Contractual Obligations [Abstract]
Corporate debt			213,467	0
Loans with credit institutions (project debt)	[1]		3,415,853	3,466,961
Notes and bonds (project debt)			707,730	706,151
Purchase commitments			2,518,087	2,247,812
Accrued interest estimate during the useful life of loans			1,598,876	$ 1,862,563
Pemex [Member]
Legal Proceedings [Abstract]
Estimated claims			20,000
Arb Inc. [Member]
Legal Proceedings [Abstract]
Estimated claims			33,000
Group of Insurance Companies [Member]
Legal Proceedings [Abstract]
Estimated claims			$ 200,000
[1]	According to contracted maturities.

Other operating income and ex92

Other operating income and expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other operating income [Abstract]
Grants	$ 59,707	$ 59,085	$ 67,859
Income from various services and insurance proceeds	21,137	6,453	998
Total	80,844	65,538	68,857
Other operating expenses [Abstract]
Leases and fees	(6,641)	(5,309)	(3,865)
Operation and maintenance	(129,873)	(133,292)	(116,405)
Independent professional services	(36,178)	(30,515)	(19,046)
Supplies	(20,350)	(17,177)	(18,001)
Insurance	(24,289)	(23,390)	(20,277)
Levies and duties	(52,409)	(44,440)	(32,352)
Other expenses	(14,721)	(6,195)	(14,882)
Total	$ (284,461)	$ (260,318)	$ (224,828)

Financial Income and expenses93

Financial Income and expenses (Details) - USD ($) $ in Thousands	Mar. 15, 2017	Feb. 24, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial income [Abstract]
Interest income from loans and credits			$ 325	$ 286	$ 933
Interest rates benefits derivatives: cash flow hedges			682	3,012	2,531
Total			1,007	3,298	3,464
Financial expenses [Abstract]
Expenses due to interest - Loans from credit entities			(253,660)	(242,919)	(197,929)
Expenses due to interest - Other debts			(137,562)	(90,995)	(81,853)
Interest rates losses derivatives: cash flow hedges			(72,495)	(74,093)	(54,139)
Total			(463,717)	(408,007)	(333,921)
Other financial income / (expenses) [Abstract]
Dividend from ACBH (Brazil)			10,383	27,948	18,400
Impairment preferred equity investment in ACBH (see Note 8)			0	(22,076)	(210,435)
Other financial income			28,809	13,027	1,520
Other financial losses			(20,758)	(10,394)	(9,638)
Total			18,434	$ 8,505	$ (200,153)
Dividends retained from Abengoa		$ 10,400
Liberty [Member]
Financial expenses [Abstract]
Increase in amortized cost			50,000
Abengoa [Member]
Other financial income / (expenses) [Abstract]
Dividends retained from Abengoa	$ 10,400
Loss from derecognition of fair value assigned to preferred equity investment and recognition of debt and equity instruments			5,800
Other financial income resulting from termination of currency swap agreement			16,200
Profit resulting from sale of major part of debt and equity instruments			$ 6,500

Earnings per share (Details)

Earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings per share [Abstract]
Profit/(loss) from continuing operations attributable to Atlantica Yield Plc.	$ (111,804)	$ (4,855)	$ (209,005)
Profit/(loss) from discontinuing operations attributable to Atlantica Yield Plc.	$ 0	$ 0	$ 0
Average number of ordinary shares outstanding (thousands) - basic and diluted (in shares)	100,217	100,217	92,795
Earnings per share from continuing operations (US dollar per share) - basic and diluted (in dollars per share)	$ (1.12)	$ (0.05)	$ (2.25)
Earnings per share from discontinuing operations (US dollar per share) - basic and diluted (in dollars per share)	0	0	0
Earnings per share from profit/ (loss) for the period (US dollar per share) - basic and diluted (in dollars per share)	$ (1.12)	$ (0.05)	$ (2.25)

Other information (Details)

Other information (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 28, 2018	Dec. 31, 2017
Restricted net assets [Abstract]
Restricted net assets		$ 566
Subsequent Event [Member]
Subsequent Events [Abstract]
Dividends declared (in dollars per share)	$ 0.31

Schedule I, Condensed Financi96

Schedule I, Condensed Financial Statements, of financial position (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 18, 2014
Assets [Abstract]
Cash and cash equivalents	$ 669,387	$ 594,811	$ 514,712	$ 354,154
Total assets	10,492,339	10,297,799
Liabilities and Equity [Abstract]
Total liabilities	8,596,886	8,338,688
Common Stock	10,022	10,022			$ 2,485
Distributable reserves	(477,214)	(365,410)
Total equity	1,895,453	1,959,111	2,023,501	1,839,631
Total equity and liabilities	10,492,339	10,297,799
Parent Company [Member]
Assets [Abstract]
Investment in affiliates	2,044,967	2,035,598
Loans to affiliates	647,911	704,916
Cash and cash equivalents	148,525	122,154	45,487	$ 155,367
Other assets	3,704	23,936
Total assets	2,845,107	2,886,604
Liabilities and Equity [Abstract]
Borrowings	386,616	412,839
Notes and bonds	256,468	255,362
Intercompany liabilities	103,796	54,687
Other liabilities	11,168	10,296
Total liabilities	758,048	733,184
Common Stock	10,022	10,022
Additional paid-in capital	1,981,881	1,981,881
Distributable reserves	42,410	116,375
Other reserves	181	13,879
Accumulated gains (losses)-net	52,565	31,263
Total equity	2,087,059	2,153,420	$ 2,158,021
Total equity and liabilities	$ 2,845,107	$ 2,886,604

Schedule I, Condensed Financi97

Schedule I, Condensed Financial Statements, of condensed income statements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income from [Abstract]
Total income	$ 1,008,381	$ 971,797	$ 790,881
Expenses [Abstract]
Other operating expenses	(284,461)	(260,318)	(224,828)
Profit/(loss) before income tax	14,950	3,333	(174,396)
Income tax benefits/(expense)	(119,837)	(1,666)	(23,790)
Profit/(loss) for the year attributable to the Company	(111,804)	(4,855)	(209,005)
Parent Company [Member]
Income from [Abstract]
Services	123,944	114,653	65,170
Other financial income	17,419	8	194
Total income	141,363	114,661	65,364
Expenses [Abstract]
Other operating expenses	(21,173)	(26,132)	(10,005)
Interest	(46,292)	(35,615)	(27,783)
Other financial expenses	(21,333)	(21,651)	(246,982)
Total expenses	(88,798)	(83,398)	(284,770)
Profit/(loss) before income tax	52,565	31,263	(219,406)
Income tax benefits/(expense)	0	0	(209)
Profit/(loss) for the year attributable to the Company	$ 52,565	$ 31,263	$ (219,615)

Schedule I, Condensed Financi98

Schedule I, Condensed Financial Statements, of condensed other comprehensive income statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other comprehensive income statement [Abstract]
Profit/(loss) for the year	$ (104,887)	$ 1,667	$ (198,186)
Items that may be subject to transfer to income statement [Abstract]
Change in fair value of cash flow hedges	(28,535)	(37,480)	56
Net income/(expenses) recognized directly in equity	97,815	(47,075)	(89,399)
Cash flow hedges	70,953	72,774	55,841
Transfer to income statement	53,215	54,580	41,881
Other comprehensive income/(loss)	151,030	7,505	(47,518)
Total comprehensive income/(loss) for the year	46,143	9,172	(245,704)
Parent Company [Member]
Other comprehensive income statement [Abstract]
Profit/(loss) for the year	52,565	31,263	(219,615)
Items that may be subject to transfer to income statement [Abstract]
Change in fair value of cash flow hedges	(13,666)	7,213	3,683
Net income/(expenses) recognized directly in equity	(13,666)	7,213	3,683
Cash flow hedges	(32)	2,321	662
Transfer to income statement	(32)	2,321	662
Other comprehensive income/(loss)	(13,698)	9,534	4,345
Total comprehensive income/(loss) for the year	$ 38,867	$ 40,797	$ (215,270)

Schedule I, Condensed Financi99

Schedule I, Condensed Financial Statements, of condensed cash flow statements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed cash flow statements [Abstract]
Cash Flow from operating activities	$ 385,623	$ 334,418	$ 299,485
Cash Flow-investing activities [Abstract]
B. Net cash used in investing activities	71,368	(26,359)	(929,850)
Cash Flow-financing activities [Abstract]
Dividend paid to shareowner	(99,483)	(35,509)	(137,166)
C. Net cash provided by/(used in) financing activities	(416,327)	(226,103)	810,931
Net increase/(decrease) in cash and cash equivalents	40,664	81,956	180,566
Cash, cash equivalents and bank overdrafts at beginning of the year	594,811	514,712	354,154
Cash and cash equivalents at the end of the year	669,387	594,811	514,712
Parent Company [Member]
Condensed cash flow statements [Abstract]
Cash Flow from operating activities	34,937	5,911	(15,943)
Cash Flow-investing activities [Abstract]
Decrease (increase) in investment and advance to affiliates	151,033	97,341	(939,503)
Net decrease (increase) in other assets	0	0	(157)
B. Net cash used in investing activities	151,033	97,341	(939,660)
Cash Flow-financing activities [Abstract]
Net increase/(decrease) in borrowings and other liabilities	(64,754)	0	310,462
Dividend paid to shareowner	(94,845)	(26,585)	(128,859)
Capital increase and other	0	0	664,120
C. Net cash provided by/(used in) financing activities	(159,599)	(26,585)	845,723
Net increase/(decrease) in cash and cash equivalents	26,371	76,667	(109,880)
Cash, cash equivalents and bank overdrafts at beginning of the year	122,154	45,487	155,367
Cash and cash equivalents at the end of the year	$ 148,525	$ 122,154	$ 45,487

Schedule I, Condensed Financ100

Schedule I, Condensed Financial Statements, Notes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Profit/(Loss) Reconciliation [Abstract]
Profit/(loss) for the period	$ (111,804)	$ (4,855)	$ (209,005)
Additional profit/(loss) if subsidiaries had been accounted for using the equity method of accounting as opposed to cost method	5,351	6,646	7,844
Equity Reconciliation [Abstract]
Shareholders equity	1,895,453	1,959,111	2,023,501	$ 1,839,631
Parent [Member]
Basis of Presentation [Abstract]
Cash dividend receivable from subsidiaries	10,383	29,737	18,400
Profit/(Loss) Reconciliation [Abstract]
Profit/(loss) for the period	52,565	31,263	(219,615)
Additional profit/(loss) if subsidiaries had been accounted for using the equity method of accounting as opposed to cost method	(164,369)	(36,118)	10,610
Equity Reconciliation [Abstract]
Shareholders equity	2,087,059	2,153,420	2,158,021
Additional shareholders equity if subsidiaries had been accounted for using the equity method of accounting as opposed to cost method	$ (191,606)	$ (194,309)	$ (134,520)