Enphase Energy (ENPH) 10-Q 7 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 30, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'Enphase Energy, Inc.	'
Entity Central Index Key	'0001463101	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-14	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	42,613,014

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$39,935	$38,190
Accounts receivable, net of allowances of $2,026 and $2,000	28,450	32,084
Inventory	14,113	16,580
Prepaid expenses and other	4,283	3,655
Total current assets	86,781	90,509
Property and equipment, net	24,809	24,853
Other assets	1,570	1,307
Total assets	113,160	116,669
Current liabilities:	'	'
Accounts payable	9,353	7,363
Accrued liabilities	13,578	14,780
Deferred revenues	1,900	2,773
Warranty obligations, current portion (includes $126 and $0 measured at fair value at March 31, 2014 and December 31, 2013, respectively)	5,894	4,942
Term loans, current portion	3,370	3,507
Total current liabilities	34,095	33,365
Long-term liabilities:	'	'
Deferred revenues, noncurrent	12,064	11,284
Warranty obligations, noncurrent (includes $461 and $0 measured at fair value at March 31, 2014 and December 31, 2013, respectively)	24,834	25,490
Other liabilities	1,272	1,154
Term loans, noncurrent	4,457	5,170
Total liabilities	76,722	76,463
Commitments and contingencies	'	'
Stockholders’ equity:	'	'
Preferred stock, $0.00001 par value, 10,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.00001 par value, 100,000 shares authorized; 42,354 and 42,123 shares issued and outstanding as of March 31, 2014 and December 31, 2013, respectively	0	0
Additional paid-in capital	195,383	192,916
Accumulated deficit	-159,175	-152,939
Accumulated other comprehensive income	230	229
Total stockholders’ equity	36,438	40,206
Total liabilities and stockholders’ equity	$113,160	$116,669

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited ) (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Allowances, accounts receivable	$2,026	$2,000
Warranty obligations, current at fair value	126	0
Warranty obligations, non-current at fair value	$461	$0
Common stock, par value (usd per share)	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	42,354,000	42,123,000
Common stock, shares outstanding	42,354,000	42,123,000
Preferred stock, par value (usd per share)	$0.00	$0.00
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net revenues	$57,580	$45,577
Cost of revenues	38,925	33,376
Gross profit	18,655	12,201
Operating expenses:	'	'
Research and development	9,086	9,026
Sales and marketing	8,828	6,850
General and administrative	6,526	6,036
Total operating expenses	24,440	21,912
Loss from operations	-5,785	-9,711
Other income (expense), net:	'	'
Interest expense	-449	-464
Other income (expense)	107	-49
Total other expense, net	-342	-513
Loss before income taxes	-6,127	-10,224
Provision for income taxes	-109	-182
Net loss	($6,236)	($10,406)
Net loss per share attributable to common stockholders, basic and diluted (usd per share)	($0.15)	($0.25)
Shares used in computing net loss per share, basic and diluted	42,205	41,149

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net loss	($6,236)	($10,406)
Other comprehensive (loss) income:	'	'
Foreign currency translation adjustments	1	-178
Comprehensive loss	($6,235)	($10,584)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:	'	'
Net loss	($6,236)	($10,406)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	1,910	1,660
Provision for doubtful accounts	26	0
Net loss on disposal of assets	6	0
Non-cash interest expense	102	108
Stock-based compensation	2,013	1,435
Changes in operating assets and liabilities:	'	'
Accounts receivable	3,608	2,835
Inventory	2,467	-2,466
Prepaid expenses and other assets	-977	-355
Accounts payable, accrued compensation and other accrued liabilities	1,159	-3,316
Warranty obligations	296	2,557
Deferred revenues	-93	976
Net cash provided by (used in) operating activities	4,281	-6,972
Cash flows from investing activities:	'	'
Purchases of property and equipment	-2,172	-1,682
Net cash used in investing activities	-2,172	-1,682
Cash flows from financing activities:	'	'
Repayments of term loans	-866	-591
Principal payments under capital leases	0	-40
Proceeds from issuance of common stock under employee stock plans	454	603
Net cash used in financing activities	-412	-28
Effect of exchange rate changes on cash	48	-178
Net increase (decrease) in cash and cash equivalents	1,745	-8,860
Cash and cash equivalents—Beginning of period	38,190	45,294
Cash and cash equivalents—End of period	39,935	36,434
Supplemental disclosures of non-cash investing and financing activities:	'	'
Purchases of property and equipment included in accounts payable	$497	$490

Overview_and_Summary_of_Signif

Overview and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Overview and Summary of Significant Accounting Policies	'
	Overview and Summary of Significant Accounting Policies
	The Company
	Enphase Energy, Inc. ("Enphase" or the “Company”) designs, develops, and sells microinverter systems for the solar photovoltaic industry. The Company’s microinverter system consists of (i) an Enphase microinverter and related accessories that convert direct current (“DC”) power to grid-compliant alternating current (“AC”) power; (ii) an Envoy communications gateway device that collects and transmits performance information from each solar module to the Company’s hosted data center; and (iii) the Enlighten web-based software platform that collects and processes this information to enable customers to monitor and manage their solar power systems. The Company sells microinverter systems primarily to distributors who resell them to solar installers. The Company also sells directly to large installers as well as through original equipment manufacturers (“OEMs”) and strategic partners.
	Basis of Presentation and Consolidation
	The accompanying condensed consolidated financial statements are presented in accordance with accounting principles generally accepted in the United States. The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in the consolidation.
	Certain reclassifications of prior year's balances have been made to conform to current year presentation, including separately presenting balances for "Warranty obligations" in current liabilities on the condensed consolidated balance sheet and under changes in operating assets and liabilities on the condensed consolidated statements of cash flow.
	Unaudited Interim Financial Information
	These accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of normal recurring items, considered necessary to present fairly the Company's financial condition, results of operations, comprehensive loss and cash flows for the periods indicated. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the operating results for the full year. Certain information and footnote disclosures typically included in annual consolidated financial statements have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.
	Except for the the election to account for all eligible warranty obligations associated with microinverters sold since January 1, 2014 at fair value, there have been no material changes in the Company's significant accounting policies during the three months ended March 31, 2014 as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2013. Reference is made to the disclosures therein for a summary of all of the Company’s significant accounting policies.
	Use of Estimates
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions about future events, and apply judgments that affect the reported amounts of assets, liabilities, revenue, expenses and the related disclosures. Significant estimates and assumptions reflected in the financial statements include revenue recognition, inventory valuation and accrued warranty obligations. Actual results could differ from those estimates.
	Fair Value Option for Microinverters Sold Since January 1, 2014
	The Company’s warranty obligations related to microinverters sold since January 1, 2014 provide the Company the right, but not the requirement, to assign its warranty obligations to a third-party. Under Accounting Standards Codification ("ASC") 825—Financial Instruments, ("fair value option"), an entity may choose to elect the fair value option for such warranties at the time it first recognizes the eligible item. The Company made an irrevocable election to account for all eligible warranty obligations associated with microinverters sold since January 1, 2014 at fair value. This election was made to reflect the underlying economics of the time value of money for an obligation that will be settled over an extended period of up to 25 years. See Note 4—Fair Value Measurements.
	The Company estimates the fair value of warranty obligations by calculating the warranty obligations in the same manner as for sales prior to January 1, 2014 and applying an expected present value technique to that result. The expected present value technique, an income approach, converts future amounts into a single current discounted amount. In addition to the key estimates of failure rates, claim rates and replacement costs, the Company used certain Level 3 inputs which are unobservable and significant to the overall fair value measurement. Such additional assumptions included a discount rate based on the Company's credit-adjusted risk-free rate and compensation comprised of a profit element and risk premium required of a market participant to assume the obligation. Warranty obligations initially recorded at fair value at the time of sale will be subsequently re-measured to fair value at each reporting date. In addition, the fair value of the liability will be accreted over the corresponding term of the warranty of up to 25 years using the interest method. Any changes in fair value of the liability from period-to-period, including accretion expense, will be recognized in cost of revenues. As of March 31, 2014, warranty obligations associated with sales prior to December 31, 2013 were $30.1 million and warranty obligations associated with sales subsequent to December 31, 2013 were $629,000, of which $587,000 were eligible for fair value accounting. The portion of warranty obligations arising from sales subsequent to December 31, 2013 that were not eligible for fair value accounting relates to sales of non-microinverter products. Periodic adjustments necessitated by actual experience of claims and any future changes in estimates to amounts not eligible for fair value accounting will continue to be accounted for on an undiscounted basis.

Inventory

Inventory	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
INVENTORY	'
	INVENTORY
	Inventory as of March 31, 2014 and December 31, 2013 consists of the following (in thousands):
		March 31,		December 31,
		2014		2013
	Raw materials	$	1,916	$	1,428
	Finished goods	12,197		15,152
	Total inventory	$	14,113	$	16,580

Warranty_Obligations

Warranty Obligations	3 Months Ended
	Mar. 31, 2014
Product Warranties Disclosures [Abstract]	'
WARRANTY OBLIGATIONS	'
	WARRANTY OBLIGATIONS
	The Company’s warranty activities during the three months ended March 31, 2014 and 2013 were as follows (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Warranty obligations, beginning of period	$	30,432		$	21,338
	Accruals for warranties issued during period	613			1,474
	Changes in estimates	1,400			2,051
	Settlements	(1,733		)	(968		)
	Increase due to accretion expense	20			—
	Other	(4		)	—
	Warranty obligations, end of period	$	30,728		$	23,895
	Less current portion	$	(5,894	)	$	(6,801	)
	Noncurrent	$	24,834		$	17,094
	As of March 31, 2014, the $30.7 million in warranty obligations included $587,000 measured at fair value (see Note 4—Fair Value Measurements). The portion of warranty obligations arising from sales subsequent to December 31, 2013 that were not eligible for fair value accounting relates to sales of non-microinverter products.
	Included within warranty expense in the three months ended March 31, 2014 and 2013 were net changes in estimates of $1.4 million and $2.1 million, respectively, to reflect higher than originally estimated replacement unit costs related to the Company's second generation microinverter.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
FAIR VALUE OF FINANCIAL INSTRUMENTS	'
	FAIR VALUE MEASUREMENTS
	The accounting guidance defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance.
	The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. An asset’s or liability’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value:
	•	Level 1—Valuations based on quoted prices in active markets for identical assets or liabilities that the Company is able to access. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of such assets or liabilities do not entail a significant degree of judgment.
	•	Level 2—Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly.
	•	Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement.
	Derivative Instruments
	The Company utilizes foreign currency forward contracts from time to time to reduce the impact of foreign currency fluctuations arising from both sales and purchases denominated in Euros and the British Pound Sterling.
	The Company did not have any foreign currency forward contracts outstanding at March 31, 2014. The following table presents the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy at December 31, 2013 (in thousands):
		As of December 31, 2013
		Asset Derivatives				Liability Derivatives
	Foreign currency forward contracts (Level 2)	$	325			$	605
	For the three months ended March 31, 2014 and 2013, the Company recorded net gains of $50,000 and $86,000, respectively, related to foreign currency forward contracts in other income (expense), net.
	Fair Value Option for Warranty Obligations Related to Microinverters Sold Since January 1, 2014
	The Company estimates the fair value of warranty obligations by calculating the warranty obligations in the same manner as for sales prior to January 1, 2014 and applying an expected present value technique to that result. The expected present value technique, an income approach, converts future amounts into a single current discounted amount. In addition to the key estimates of failure rates, claim rates and replacement costs, the Company used certain Level 3 inputs which are unobservable and significant to the overall fair value measurement. Such additional assumptions included a discount rate based on the Company's credit-adjusted risk-free rate and compensation comprised of a profit element and risk premium required of a market participant to assume the obligation.
	The following table presents the Company's warranty obligations measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2014 (in thousands):
		Warranty Obligations Measured at Fair Value
	Balance—December 31, 2013	$	—
	Accruals for warranties issued during period	571
	Settlements	—
	Increase due to accretion expense	20
	Other	(4		)
	Balance—March 31, 2014	$	587
	Quantitative and Qualitative Information about Level 3 Fair Value Measurements
	The significant unobservable inputs used in the fair value measurement of the Company's warranty obligations designated as Level 3 are as follows:
	Item Measured at Fair Value		Valuation Technique		Description of Significant Unobservable Input		Percent Used
	Warranty obligations for microinverters sold since January 1, 2014		Discounted cash flows		Profit element and risk premium		16%
					Credit-adjusted risk-free rate (discount rate)		14%
	An increase (decrease) in the profit element and risk premium input in isolation would result in a higher (lower) fair value measurement of the liability. A significant increase (decrease) in the discount rate in isolation would result in a substantially lower (higher) fair value measurement of the liability.

Term_Loans

Term Loans	3 Months Ended
	Mar. 31, 2014
Long-term Debt, by Current and Noncurrent [Abstract]	'
TERM LOANS	'
	TERM LOANS
	The Company’s long-term debt at March 31, 2014 and December 31, 2013 consists of the following (in thousands):
		March 31,			December 31,
		2014			2013
	Term loans	$	7,181		$	7,400
	Equipment financing facility, net of unamortized discount of $16 and $31, respectively	646			1,277
	Total term loans	7,827			8,677
	Less current portion	(3,370		)	(3,507		)
	Term loans, noncurrent	$	4,457		$	5,170
	As of March 31, 2014, the Company was a party to three debt agreements: (i) a $50.0 million revolving credit facility (the "Revolver") with Wells Fargo Bank, N.A., (ii) a facility with Hercules Technology Growth Capital, Inc. (“Hercules Facility”) consisting of an initial draw in the amount of $7.4 million under the facility and a commitment to provide an incremental line of credit of up to $15.6 million through March 31, 2014, and (iii) a $5.0 million equipment financing facility, also with Hercules. Each of these debt agreements is described in greater detail in the consolidated financial statements and related notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.
	On February 14, 2014, the Company entered into an amendment to the Revolver which extended the maturity date from November 7, 2015 to November 7, 2016. In addition, the amendment lowered the minimum liquidity covenant in undrawn availability from $8.0 million to $5.0 million in cash while maintaining at least $15.0 million of liquidity (defined as the sum of cash and the borrowing base) at all times. To date, the Company has not drawn on the Revolver.
	On March 31, 2014, the undrawn $15.6 million incremental line of credit under the Hercules Facility expired in accordance with its terms as the Company elected not to renew this incremental line of credit. As of March 31, 2014, the outstanding principal balance under the Hercules Facility was $7.2 million.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
COMMITMENTS AND CONTINGENCIES	'
	COMMITMENTS AND CONTINGENCIES
	Contingencies —The Company is not currently involved in any material legal proceedings. The Company may become involved in various legal proceedings and claims that arise in the ordinary course of business. Such matters are subject to uncertainty and there can be no assurance that such legal proceedings will not have a material adverse effect on its business, results of operations, financial position or cash flows.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
STOCK-BASED COMPENSATION	'
	STOCK-BASED COMPENSATION
	The Company has adopted certain equity incentive and stock purchase plans as described in the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.
	Equity Awards Activity
	Stock Options
	The following is a summary of stock option activity for the three months ended March 31, 2014 (in thousands, except per share data):
		Number of			Weighted-
		Shares			Average
		Outstanding			Exercise Price
					per Share
	Outstanding at December 31, 2013	8,509			$	3.94
	Granted	228			7.82
	Exercised	(202	)		2.25
	Canceled	(83	)		7.53
	Outstanding at March 31, 2014	8,452			4.05
	The intrinsic value of options exercised in the three months ended March 31, 2014 was $1.1 million. As of March 31, 2014, the intrinsic value of options outstanding was $30.4 million based on the closing price of the Company's stock as of March 31, 2014.
	Restricted Stock Units
	The following is a summary of restricted stock unit activity for the three months ended March 31, 2014 (in thousands, except per share data):
		Restricted Stock Units			Weighted Average
					Fair Value per Share at
					Grant Date
	Outstanding at December 31, 2013	418			$	6.31
	Granted	1,160			8.44
	Vested	(29	)		6
	Canceled	(1	)		6.6
	Outstanding at March 31, 2014	1,548			7.91
	The total fair value of restricted stock units that vested in the three months ended March 31, 2014 was $0.2 million. As of March 31, 2014, the intrinsic value of restricted stock units outstanding was $11.4 million based on the closing price of the Company's stock as of March 31, 2014.
	Stock-Based Compensation Expense
	Compensation cost for all stock-based awards expected to vest is measured at fair value on the date of grant and recognized ratably over the requisite service period. The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations for the periods presented (in thousands):
		Three Months Ended
		March 31,
		2014				2013
	Cost of revenues	$	149			$	108
	Research and development	613				478
	Sales and marketing	532				378
	General and administrative	719				471
	Total	$	2,013			$	1,435
	The following table summarizes stock-based compensation associated with each type of award for the periods presented (in thousands):
		Three Months Ended
		March 31,
		2014				2013
	Stock options and restricted stock units	$	1,839			$	1,285
	Employee stock purchase plan	174				150
	Total	$	2,013			$	1,435
	Valuation Assumptions
	The fair value of option awards is estimated on the date of the grant using the Black-Scholes option pricing model with the following input assumptions:
	•	Expected term—The expected term of the option awards represents the period of time between the grant date of the option awards and the date the option awards are either exercised, converted or canceled, including an estimate for those option awards still outstanding.
	•	Expected volatility—The Company uses the simplified method, as permitted by the SEC for companies with a limited history of stock option exercise activity, to determine the expected term for its option grants. Expected stock price volatility is determined based on an average of the historical volatilities of the common stock of several companies with characteristics similar to those of the Company.
	•	Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant and with a maturity that approximates our expected term.
	•	Dividend yield—The dividend yield is based on our dividend history and the anticipated dividend payout over our expected term.
	The following table presents the weighted-average assumptions used to estimate the fair values of the stock options granted in the periods presented
		Three Months Ended
		March 31,
		2014				2013
	Expected term (in years)	4.6				4.7
	Expected volatility	62.2		%		73		%
	Annual risk-free rate of return	1.4		%		0.8		%
	Dividend yield	0		%		0		%
	Weighted average grant date fair value	$	3.99			$	2.85
	The fair value of restricted stock units granted is determined based on the price of the Company's common stock on the date of grant.
	As of March 31, 2014, there was approximately $20.8 million of total unrecognized compensation cost related to unvested equity awards expected to be recognized over a weighted-average period of 3.0 years.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
INCOME TAXES	'
	INCOME TAXES
	No provision for U.S. federal or state income taxes has been made due to cumulative losses since the commencement of operations. The Company had a provision for income taxes of $109,000 and $182,000 for the three months ended March 31, 2014 and 2013, respectively. The provision relates to the Company's subsidiaries located outside of the United States.

Net_Loss_Per_Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
NET LOSS PER SHARE	'
	NET LOSS PER SHARE
	The following table presents the computation of basic and diluted net loss per share (in thousands, except per share data):
		Three Months Ended
		March 31,
		2014				2013
	Numerator:
	Net loss	$	(6,236	)		$	(10,406	)
	Denominator:
	Weighted average number of common shares outstanding	42,205				41,149
	Net loss per share, basic and diluted	$	(0.15	)		$	(0.25	)
	As the Company incurred a net loss for all periods presented, potential dilutive securities from employee stock options, restricted stock units and warrants have been excluded from the diluted net loss per share computations because the effect of including such shares would have been anti-dilutive. The following table sets forth the potentially dilutive securities excluded from the computation of the diluted net loss per share (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Employee stock options	8,489			7,908
	Restricted stock units	732			247
	Warrants to purchase common stock	293			331
	Total	9,514			8,486

Overview_and_Summary_of_Signif1

Overview and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation, Consolidation and Related Party Transactions	'
	Basis of Presentation and Consolidation
	The accompanying condensed consolidated financial statements are presented in accordance with accounting principles generally accepted in the United States. The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in the consolidation.
	Unaudited Interim Financial Information
	These accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of normal recurring items, considered necessary to present fairly the Company's financial condition, results of operations, comprehensive loss and cash flows for the periods indicated. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the operating results for the full year. Certain information and footnote disclosures typically included in annual consolidated financial statements have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.
Reclassifications	'
	Certain reclassifications of prior year's balances have been made to conform to current year presentation, including separately presenting balances for "Warranty obligations" in current liabilities on the condensed consolidated balance sheet and under changes in operating assets and liabilities on the condensed consolidated statements of cash flow.
Unaudited Interim Financial Information	'
	Unaudited Interim Financial Information
	These accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of normal recurring items, considered necessary to present fairly the Company's financial condition, results of operations, comprehensive loss and cash flows for the periods indicated. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the operating results for the full year. Certain information and footnote disclosures typically included in annual consolidated financial statements have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions about future events, and apply judgments that affect the reported amounts of assets, liabilities, revenue, expenses and the related disclosures. Significant estimates and assumptions reflected in the financial statements include revenue recognition, inventory valuation and accrued warranty obligations. Actual results could differ from those estimates.
Fair Value Option for Microinverters Sold Since January 1, 2014	'
	Fair Value Option for Microinverters Sold Since January 1, 2014
	The Company’s warranty obligations related to microinverters sold since January 1, 2014 provide the Company the right, but not the requirement, to assign its warranty obligations to a third-party. Under Accounting Standards Codification ("ASC") 825—Financial Instruments, ("fair value option"), an entity may choose to elect the fair value option for such warranties at the time it first recognizes the eligible item. The Company made an irrevocable election to account for all eligible warranty obligations associated with microinverters sold since January 1, 2014 at fair value. This election was made to reflect the underlying economics of the time value of money for an obligation that will be settled over an extended period of up to 25 years. See Note 4—Fair Value Measurements.
	The Company estimates the fair value of warranty obligations by calculating the warranty obligations in the same manner as for sales prior to January 1, 2014 and applying an expected present value technique to that result. The expected present value technique, an income approach, converts future amounts into a single current discounted amount. In addition to the key estimates of failure rates, claim rates and replacement costs, the Company used certain Level 3 inputs which are unobservable and significant to the overall fair value measurement. Such additional assumptions included a discount rate based on the Company's credit-adjusted risk-free rate and compensation comprised of a profit element and risk premium required of a market participant to assume the obligation. Warranty obligations initially recorded at fair value at the time of sale will be subsequently re-measured to fair value at each reporting date. In addition, the fair value of the liability will be accreted over the corresponding term of the warranty of up to 25 years using the interest method. Any changes in fair value of the liability from period-to-period, including accretion expense, will be recognized in cost of revenues. As of March 31, 2014, warranty obligations associated with sales prior to December 31, 2013 were $30.1 million and warranty obligations associated with sales subsequent to December 31, 2013 were $629,000, of which $587,000 were eligible for fair value accounting. The portion of warranty obligations arising from sales subsequent to December 31, 2013 that were not eligible for fair value accounting relates to sales of non-microinverter products. Periodic adjustments necessitated by actual experience of claims and any future changes in estimates to amounts not eligible for fair value accounting will continue to be accounted for on an undiscounted basis.

Inventory_Tables

Inventory (Tables)	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
Schedule of inventory	'
	Inventory as of March 31, 2014 and December 31, 2013 consists of the following (in thousands):
		March 31,		December 31,
		2014		2013
	Raw materials	$	1,916	$	1,428
	Finished goods	12,197		15,152
	Total inventory	$	14,113	$	16,580

Warranty_Obligations_Tables

Warranty Obligations (Tables)	3 Months Ended
	Mar. 31, 2014
Product Warranties Disclosures [Abstract]	'
Changes in the Company's product warranty liability	'
	The Company’s warranty activities during the three months ended March 31, 2014 and 2013 were as follows (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Warranty obligations, beginning of period	$	30,432		$	21,338
	Accruals for warranties issued during period	613			1,474
	Changes in estimates	1,400			2,051
	Settlements	(1,733		)	(968		)
	Increase due to accretion expense	20			—
	Other	(4		)	—
	Warranty obligations, end of period	$	30,728		$	23,895
	Less current portion	$	(5,894	)	$	(6,801	)
	Noncurrent	$	24,834		$	17,094

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Schedule of financial instruments that are measured at fair value on a recurring basis	'
	The following table presents the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy at December 31, 2013 (in thousands):
		As of December 31, 2013
		Asset Derivatives				Liability Derivatives
	Foreign currency forward contracts (Level 2)	$	325			$	605
Schedule of warranty obligations measured at fair value on a recurring basis	'
	The following table presents the Company's warranty obligations measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2014 (in thousands):
		Warranty Obligations Measured at Fair Value
	Balance—December 31, 2013	$	—
	Accruals for warranties issued during period	571
	Settlements	—
	Increase due to accretion expense	20
	Other	(4		)
	Balance—March 31, 2014	$	587
Schedule of significant unobservable inputs used in the fair value measurement of the Company's warranty obligations designated as Level 3	'
	The significant unobservable inputs used in the fair value measurement of the Company's warranty obligations designated as Level 3 are as follows:
	Item Measured at Fair Value		Valuation Technique		Description of Significant Unobservable Input		Percent Used
	Warranty obligations for microinverters sold since January 1, 2014		Discounted cash flows		Profit element and risk premium		16%
					Credit-adjusted risk-free rate (discount rate)		14%

Term_Loans_Tables

Term Loans (Tables)	3 Months Ended
	Mar. 31, 2014
Long-term Debt, by Current and Noncurrent [Abstract]	'
Schedule of long-term debt	'
	The Company’s long-term debt at March 31, 2014 and December 31, 2013 consists of the following (in thousands):
		March 31,			December 31,
		2014			2013
	Term loans	$	7,181		$	7,400
	Equipment financing facility, net of unamortized discount of $16 and $31, respectively	646			1,277
	Total term loans	7,827			8,677
	Less current portion	(3,370		)	(3,507		)
	Term loans, noncurrent	$	4,457		$	5,170

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of summary of stock option activity	'
	The following is a summary of stock option activity for the three months ended March 31, 2014 (in thousands, except per share data):
		Number of			Weighted-
		Shares			Average
		Outstanding			Exercise Price
					per Share
	Outstanding at December 31, 2013	8,509			$	3.94
	Granted	228			7.82
	Exercised	(202	)		2.25
	Canceled	(83	)		7.53
	Outstanding at March 31, 2014	8,452			4.05
Schedule of restricted stock unit activity	'
	The following is a summary of restricted stock unit activity for the three months ended March 31, 2014 (in thousands, except per share data):
		Restricted Stock Units			Weighted Average
					Fair Value per Share at
					Grant Date
	Outstanding at December 31, 2013	418			$	6.31
	Granted	1,160			8.44
	Vested	(29	)		6
	Canceled	(1	)		6.6
	Outstanding at March 31, 2014	1,548			7.91
Schedule of components of stock-based compensation expense in the consolidated statement of operations, by report line	'
	The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations for the periods presented (in thousands):
		Three Months Ended
		March 31,
		2014				2013
	Cost of revenues	$	149			$	108
	Research and development	613				478
	Sales and marketing	532				378
	General and administrative	719				471
	Total	$	2,013			$	1,435
Schedule of stock-based compensation expense by award type	'
	The following table summarizes stock-based compensation associated with each type of award for the periods presented (in thousands):
		Three Months Ended
		March 31,
		2014				2013
	Stock options and restricted stock units	$	1,839			$	1,285
	Employee stock purchase plan	174				150
	Total	$	2,013			$	1,435
Schedule of valuation assumptions of stock options	'
	The following table presents the weighted-average assumptions used to estimate the fair values of the stock options granted in the periods presented
		Three Months Ended
		March 31,
		2014				2013
	Expected term (in years)	4.6				4.7
	Expected volatility	62.2		%		73		%
	Annual risk-free rate of return	1.4		%		0.8		%
	Dividend yield	0		%		0		%
	Weighted average grant date fair value	$	3.99			$	2.85

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Schedule of computation of basic and diluted net loss per share	'
	The following table presents the computation of basic and diluted net loss per share (in thousands, except per share data):
		Three Months Ended
		March 31,
		2014				2013
	Numerator:
	Net loss	$	(6,236	)		$	(10,406	)
	Denominator:
	Weighted average number of common shares outstanding	42,205				41,149
	Net loss per share, basic and diluted	$	(0.15	)		$	(0.25	)
Schedule of potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders	'
	The following table sets forth the potentially dilutive securities excluded from the computation of the diluted net loss per share (in thousands):
		Three Months Ended
		March 31,
		2014			2013
	Employee stock options	8,489			7,908
	Restricted stock units	732			247
	Warrants to purchase common stock	293			331
	Total	9,514			8,486

Overview_and_Summary_of_Accoun

Overview and Summary of Accounting Policies (Details Textual) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
					Prior to December 31, 2013	Subsequent to December 31, 2013	Subsequent to December 31, 2013	Maximum
							Warranty obligations, fair value option
Accounting Policies [Line Items]	'	'	'	'	'	'	'	'
Product warranty term	'	'	'	'	'	'	'	'25 years
Warranty obligation	$30,728,000	$30,432,000	$23,895,000	$21,338,000	$30,100,000	$629,000	$587,000	'

Inventory_Details

Inventory (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of inventory	'	'
Raw materials	$1,916	$1,428
Finished goods	12,197	15,152
Total inventory	$14,113	$16,580

Warranty_Obligations_Details

Warranty Obligations (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Changes in the Company's product warranty liability	'	'	'
Warranty obligations, beginning of period	$30,432	$21,338	'
Accruals for warranties issued during period	613	1,474	'
Changes in estimates	1,400	2,051	'
Settlements	-1,733	-968	'
Increase due to accretion expense	20	0	'
Other	-4	0	'
Warranty obligations, end of period	30,728	23,895	'
Less current portion	-5,894	-6,801	-4,942
Noncurrent	$24,834	$17,094	$25,490

Warranty_Obligations_Details_T

Warranty Obligations (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Product Liability [Line Items]	'	'	'	'
Warranty obligation	$30,728,000	$23,895,000	$30,432,000	$21,338,000
Changes in warranty estimates	1,400,000	2,051,000	'	'
Subsequent to December 31, 2013	'	'	'	'
Product Liability [Line Items]	'	'	'	'
Warranty obligation	629,000	'	'	'
Warranty obligations, fair value option | Subsequent to December 31, 2013	'	'	'	'
Product Liability [Line Items]	'	'	'	'
Warranty obligation	$587,000	'	'	'

Fair_Value_Measurements_Financ

Fair Value Measurements Financial Instruments Measured at Fair Value (Details) (Fair value, measurements, recurring, Level 2, USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair value, measurements, recurring | Level 2	'
Asset Derivatives	'
Foreign currency forward contracts	$325
Liability Derivatives	'
Foreign currency forward contracts	$605

Fair_Value_Measurements_Warran

Fair Value Measurements Warranty Obligations Measured at Fair Value (Details) (Warranty obligations, fair value option, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Warranty obligations, fair value option	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Balance—December 31, 2013	$0
Accruals for warranties issued during period	571
Settlements	0
Increase due to accretion expense	20
Other	-4
Balance—March 31, 2014	$587

Fair_Value_Measurements_Unobse

Fair Value Measurements Unobservable Inputs Used in the Fair Value Measurement of Warranty Obligations (Details) (Warranty obligations for microinverters sold since January 1, 2014, Discounted cash flows, Level 3)	3 Months Ended
	Mar. 31, 2014
Warranty obligations for microinverters sold since January 1, 2014 | Discounted cash flows | Level 3	'
Fair Value Inputs [Abstract]	'
Profit element and risk premium	16.00%
Credit-adjusted risk-free rate (discount rate)	14.00%

Fair_Value_Measurements_Detail

Fair Value Measurements (Details Textual) (Not designated as hedging instrument, Foreign exchange forward, USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Not designated as hedging instrument | Foreign exchange forward	'	'
Derivative [Line Items]	'	'
Net gain on foreign currency	$50,000	$86,000

Term_Loans_Details

Term Loans (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of long-term debt	'	'
Total term loans	$7,827	$8,677
Less current portion	-3,370	-3,507
Term loans, noncurrent	4,457	5,170
Term loans	'	'
Schedule of long-term debt	'	'
Total term loans	7,181	7,400
Equipment financing facility, net of unamortized discount of $16 and $31, respectively	'	'
Schedule of long-term debt	'	'
Total term loans	646	1,277
Unamortized discount	$16	$31

Term_Loans_Details_Textual

Term Loans (Details Textual) (USD $)	Mar. 31, 2014	Mar. 31, 2014	Feb. 14, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2014
	debt_agreement	Wells Fargo Bank	Wells Fargo Bank	Wells Fargo Bank	Hercules Technology Growth Capital Inc	Hercules Technology Growth Capital Inc
		Revolving credit facility	Revolving credit facility	Revolving credit facility	Secured debt	Equipment financing facility
Debt Instrument [Line Items]	'	'	'	'	'	'
Number of debt agreements	3	'	'	'	'	'
Credit line facility	'	$50,000,000	'	'	'	$5,000,000
Initial draw under credit line arrangement	'	'	'	'	7,400,000	'
Incremental line of credit amount	'	'	'	'	15,600,000	'
Amount of undrawn credit for debt compliance	'	'	5,000,000	8,000,000	'	'
Amount of liquidity required for debt compliance	'	'	15,000,000	'	'	'
Undrawn incremental line of credit expired during period	'	'	'	'	15,600,000	'
Outstanding principal balance	'	'	'	'	$7,200,000	'

StockBased_Compensation_Stock_

Stock-Based Compensation Stock Option Activity (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014
Number of Shares Outstanding	'
Outstanding at December 31, 2013 (in shares)	8,509
Granted (in shares)	228
Exercised (in shares)	-202
Canceled (in shares)	-83
Outstanding at March 31, 2014 (in shares)	8,452
Weighted- Average Exercise Price per Share	'
Outstanding at December 31, 2013 (in usd per share)	$3.94
Granted (in usd per share)	$7.82
Exercised (in usd per share)	$2.25
Canceled (in usd per share)	$7.53
Outstanding at March 31, 2014 (in usd per share)	$4.05

StockBased_Compensation_Restri

Stock-Based Compensation Restricted Stock Unit Activity (Details) (Restricted stock units, USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014
Restricted stock units	'
Restricted Stock Units	'
Outstanding at December 31, 2013 (in shares)	418
Granted (in shares)	1,160
Vested (in shares)	-29
Canceled (in shares)	-1
Outstanding at March 31, 2014 (in shares)	1,548
Weighted Average Fair Value per Share at Grant Date	'
Outstanding at December 31, 2013 (in usd per share)	$6.31
Granted (in usd per share)	$8.44
Vested (in usd per share)	$6
Canceled (in usd per share)	$6.60
Outstanding at March 31, 2014 (in usd per share)	$7.91

StockBased_Compensation_Compon

Stock-Based Compensation Components of Stock-based Compensation Expense by Report Line (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]	'	'
Total stock-based compensation expense	$2,013	$1,435
Cost of revenues	'	'
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]	'	'
Total stock-based compensation expense	149	108
Research and development	'	'
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]	'	'
Total stock-based compensation expense	613	478
Sales and marketing	'	'
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]	'	'
Total stock-based compensation expense	532	378
General and administrative	'	'
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]	'	'
Total stock-based compensation expense	$719	$471

StockBased_Compensation_Expens

Stock-Based Compensation Expense by Award Type (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation expense	$2,013	$1,435
Stock options and restricted stock units	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation expense	1,839	1,285
Employee stock purchase plan	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total stock-based compensation expense	$174	$150

StockBased_Compensation_Valuat

Stock-Based Compensation Valuation Assumptions of Stock Options Under Black-Scholes Model (Details) (Stock options, USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Stock options	'	'
The fair value of each option granted during the periods	'	'
Expected term	'4 years 7 months 6 days	'4 years 8 months 12 days
Expected volatility	62.20%	73.00%
Annual risk-free rate of return	1.40%	0.80%
Dividend yield	0.00%	0.00%
Weighted average grant date fair value (usd per share)	$3.99	$2.85

StockBased_Compensation_Detail

Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Fair value of options exercised during period	$1.10
Intrinsic value of options outstanding	30.4
Total unrecognized compensation cost	20.8
Weighted-average recognition period for unrecognized compensation cost	'3 years 0 months 0 days
Restricted stock	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Fair value of stock vested during period	0.2
Intrinsic value of restricted stock units outstanding	$11.40

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Provision for U.S. federal or state income taxes	$0	'
Provision for income taxes related to subsidiaries located outside the U.S.	$109,000	$182,000

Net_Loss_Per_Share_Computation

Net Loss Per Share Computation of Basic and Diluted Net Loss Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Numerator:	'	'
Net loss	($6,236)	($10,406)
Denominator:	'	'
Weighted average number of common shares outstanding	42,205	41,149
Net loss per share, basic and diluted	($0.15)	($0.25)

Net_Loss_Per_Share_Potentially

Net Loss Per Share Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders	'	'
Total	9,514	8,486
Employee stock options	'	'
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders	'	'
Total	8,489	7,908
Restricted stock units	'	'
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders	'	'
Total	732	247
Warrants to purchase common stock	'	'
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders	'	'
Total	293	331