American DG Energy (ADGE) 8-K 5 Dec 16 2015 FY Other Events Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Mar. 30, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	AMERICAN DG ENERGY INC
Entity Central Index Key	1,378,706
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Trading Symbol	adge
Entity Common Stock, Shares Outstanding		50,684,095
Document Type	8-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,015
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 7.2

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 4,999,709	$ 8,049,063
Accounts receivable, net	633,924	988,147
Unbilled revenue	12,468	12,533
Due from related party	99,548	39,682
Inventory	975,760	1,054,002
Current assets of discontinued operations	1,450,034	4,784,215
Prepaid and other current assets	331,057	97,295
Total current assets	8,502,500	15,024,937
Property and equipment, net	17,950,787	18,536,250
Long-term assets of discontinued operations	7,527,266	6,365,669
Accounts receivable, long-term	0	3,600
Other assets, long-term	41,825	75,384
TOTAL ASSETS	34,022,378	40,005,840
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable	162,976	267,463
Accrued expenses and other current liabilities	257,810	355,318
Due to related party	1,171,863	630,805
Current liabilities of discontinued operations	699,086	468,319
Total current liabilities	2,291,735	1,721,905
Long-term liabilities:
Convertible debentures due related parties	16,078,912	14,876,949
Warrant liability	0	6,780
Long-term liabilities of discontinued operations	4,536,422	5,632,710
Other long-term liabilities	0	2,227
Total liabilities	22,907,069	22,240,571
Stockholders’ equity:
Common stock, $0.001 par value; 100,000,000 shares authorized; 50,684,095 and 52,140,001 issued and outstanding at December 31, 2015 and 2014, respectively	50,684	52,140
Additional paid-in capital	49,641,620	49,854,998
Accumulated deficit	(40,622,774)	(35,232,411)
Total American DG Energy Inc. stockholders’ equity	9,069,530	14,674,727
Noncontrolling interest in discontinued operations	1,944,236	2,606,815
Noncontrolling interest	101,543	483,727
Total stockholders’ equity	11,115,309	17,765,269
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 34,022,378	$ 40,005,840

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	50,684,095	52,140,001
Common stock, shares outstanding	50,684,095	52,140,001

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Revenues
Energy revenues	$ 5,684,774	$ 6,322,779
Turnkey & other revenues	673,422	666,901
Sales Revenue, Net, Total	6,358,196	6,989,680
Cost of sales
Fuel, maintenance and installation	4,064,145	4,634,290
Site impairments	618,661	526,766
Depreciation expense	1,728,762	1,521,440
Cost of Goods and Services Sold, Total	6,411,568	6,682,496
Gross profit (loss)	(53,372)	307,184
Operating expenses
General and administrative	1,937,299	2,361,044
Selling	694,101	586,617
Engineering	754,962	785,647
Operating Expenses, Total	3,386,362	3,733,308
Loss from operations	(3,439,734)	(3,426,124)
Other income (expense)
Interest and other income	193,691	80,246
Interest expense	(1,234,725)	(1,355,983)
Change in fair value of warrant liability	6,780	125,485
Nonoperating Income (Expense), Total	(1,034,254)	(1,150,252)
Loss from continuing operations before provision for income taxes	(4,473,988)	(4,576,376)
Provision for income taxes	(27,605)	(3,877)
Loss from continuing operations	(4,501,593)	(4,580,253)
Loss from discontinued operations	(1,384,122)	(1,945,105)
Loss from continuing operations	(5,885,715)	(6,525,358)
Loss from discontinued operations	455,312	636,464
Consolidated net loss	$ (5,430,403)	$ (5,888,894)
Net loss per share - basic and diluted (usd per share)	$ (0.11)	$ (0.12)
Weighted average shares outstanding - basic and diluted (in shares)	50,689,633	50,999,408

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock $0.001 Par Value	Additional Paid-in Capital	Accumulated Deficit	Noncontrolling Interest	Noncontrolling InterestDiscontinued Operations
Balance, Beginning (shares) at Dec. 31, 2013		49,817,920
Balance, Beginning Balance at Dec. 31, 2013	$ 12,065,911	$ 49,818	$ 40,110,305	$ (29,343,517)	$ 694,574	$ 554,731
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions to noncontrolling interest	(258,289)				(258,289)
Noncontrolling interest share of transactions affecting subsidiary ownership	(124,056)		(2,718,159)		(61,903)	2,656,006
Noncontrolling interest share of transactions affecting subsidiary ownership			4,704,500
Impact of exchange resulting from ADGNY reorganization	4,207,411		4,122,500		0	84,911
Fair value of common stock issued in conjunction with exchange of EuroSite common stock	582,000		582,000
Sale of subsidiary common stock, net of costs	1,486,329		1,486,329
Conversion of convertible debenture interest to common stock (shares)		260,154
Sale of common stock, net of costs	624,368	$ 260	624,108
Sale of common stock, net of costs (shares)		2,650,000
Sale of common stock, net of costs	$ 3,269,275	$ 2,650	3,266,625
Share repurchase program (shares)	(588,073)	(588,073)
Share repurchase program	$ (450,696)	$ (588)	(450,108)
Reacquisition by subsidiary of common stock	(42,902)		(42,902)
Conversion of subsidiary convertible debentures into subsidiary common stock	2,455,377		2,455,377
Stock-based compensation expense	475,899		418,923		0	56,976
Net loss	$ (6,525,358)			(5,888,894)	109,345	(745,809)
Balance, Ending (shares) at Dec. 31, 2014	52,140,001	52,140,001
Balance, Ending Balance at Dec. 31, 2014	$ 17,765,269	$ 52,140	49,854,998	(35,232,411)	483,727	2,606,815
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions to noncontrolling interest	(229,098)				(229,098)
Noncontrolling interest share of transactions affecting subsidiary ownership	50,057		426,980		(376,923)
Impact of exchange resulting from ADGNY reorganization (shares)		100,000
Impact of exchange resulting from ADGNY reorganization	(732,016)	$ 100	(732,116)
Fair value of common stock issued in conjunction with exchange of EuroSite common stock	0	$ (1,320)	(15,250)		0	16,570
Impact of exchange resulting from ADGNY reorganization	$ 0
Share repurchase program (shares)	(235,906)	(235,906)
Share repurchase program	$ (152,377)	$ (236)	(152,141)
Stock-based compensation expense	299,189		259,149	40,040	0
Net loss	$ (5,885,715)			(5,430,403)	223,837	(679,149)
Balance, Ending (shares) at Dec. 31, 2015	50,684,095	50,684,095
Balance, Ending Balance at Dec. 31, 2015	$ 11,115,309	$ 50,684	$ 49,641,620	$ (40,622,774)	$ 101,543	$ 1,944,236

CONSOLIDATED STATEMENTS OF STO6

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Parenthetical - $ / shares	Dec. 31, 2015	Dec. 31, 2014	May 25, 2014
Statement of Stockholders' Equity [Abstract]
Common Stock, $0.001 Par Value	$ 0.001	$ 0.001	$ 2.24

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (5,430,403)	$ (5,888,894)
Income attributable to noncontrolling interest	223,837	109,345
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	1,776,048	1,560,296
Gain attributable to distribution of nonmonetary assets to noncontrolling interest	(157,870)	0
Loss from discontinued operations	704,973	1,199,296
Non-cash site impairments	618,661	526,766
Provision for losses on accounts receivable	84,274	49,322
Amortization of deferred financing costs	60,807	48,176
Decrease in fair value of warrant liability	(6,780)	(125,485)
Non-cash interest expense	1,191,333	1,319,418
Stock-based compensation	222,130	310,900
Changes in operating assets and liabilities:
Accounts receivable and unbilled revenue	273,614	(160,731)
Due from related party	(59,767)	264,606
Inventory	78,242	806,673
Prepaid and other current assets	(261,010)	(27,852)
Increase (decrease) in:
Accounts payable	(104,487)	(400,985)
Accrued expenses and other current liabilities	(86,878)	(38,562)
Due to related party	541,058	452,589
Other long-term liabilities	(2,227)	8,486
Net cash provided by (used in) operating activities	(334,445)	13,364
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(2,238,084)	(2,806,380)
Proceeds on sale of property and equipment	4,650	0
Cash paid in connection with ADGNY reorganization	(100,000)	0
Net cash used in investing activities	(2,333,434)	(2,806,380)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from sale of common stock, net of costs	0	3,266,275
Purchases of common stock, net of costs	(152,377)	(450,596)
Distributions to noncontrolling interest	(229,098)	(258,289)
Net cash (used in) provided by financing activities	(381,475)	2,557,390
Net decrease in cash and cash equivalents	(3,049,354)	(235,626)
Cash and cash equivalents, beginning of the period	8,049,063	8,284,689
Cash and cash equivalents, end of the period	4,999,709	8,049,063
Supplemental disclosures of cash flows information:
Income taxes	48,824	59,317
Interest	0	10,000
Non-cash investing and financing activities:
Interest on convertible debentures paid in stock of subsidiary	0	585,718
Conversion of convertible debenture interest into common stock	0	624,368
Distribution of nonmonetary assets	340,069	0
Fair value of warrant exchanged for future convertible debenture interest	0	84,911
Impact of exchange resulting from ADGNY reorganization	$ 0	$ 4,207,411

The Company

The Company	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	The Company: American DG Energy Inc., or the Company, we, our or us, distributes, owns, operates and maintains clean, on-site energy systems that produce electricity, hot water, heat and cooling. The Company's business model is to own the equipment that it installs at customers' facilities and to sell the energy produced by these systems to its customers on a long-term contractual basis at prices guaranteed to the customer to be below conventional utility rates. The Company calls this business the American DG Energy “On-Site Utility”. The Company was incorporated as a Delaware corporation on July 24, 2001 to install, own, operate and maintain complete DG systems, or energy systems, and other complementary systems at customer sites and sell electricity, hot water, heat and cooling energy under long-term contracts at prices guaranteed to the customer to be below conventional utility rates. The Company derives revenues from selling energy in the form of electricity, heat, hot water and cooling to its customers under long-term energy sales agreements (with a typical term of 10 to 15 years). The energy systems are generally owned by the Company and are installed in its customers’ buildings. Each month the Company obtains readings from energy meters to determine the amount of energy produced for each customer. The Company multiplies these readings by the appropriate published price of energy (electricity, natural gas or oil) from its customers’ local energy utility, to derive the value of its monthly energy sale, less the applicable negotiated discount. The Company’s revenues per customer on a monthly basis vary based on the amount of energy produced by its energy systems and the published price of energy (electricity, natural gas or oil) from its customers’ local energy utility that month. The Company’s revenues commence as new energy systems become operational. As of December 31, 2015 , the Company had 92 energy systems operational. In some cases the customer may choose to own the system rather than have it owned by American DG Energy. Investment in EuroSite Power and Discontinued Operations During the second and third quarters of 2016, the Company settled approximately $16 million of its $19.4 million 6% convertible debentures due May 2018 (see Note 6 - Convertible Debentures) by transferring ownership of shares it owned of EuroSite Power to the holders of the debt. As a result, the Company's ownership in EuroSite decreased from 48.04% to 2.03% . During 2015 and 2014, prior to the foregoing exchanges, the Company consolidated the results of EuroSite under the variable interest model as it was determined to be the primary beneficiary of EuroSite. The exchanges were undertaken primarily as a plan to reduce future debt service requirements of the Company, however they also resulted in a disposition of all foreign operations of the Company, representing a strategic shift that will have a major effect on the Company's operations and financial results. Accordingly, amounts related to this component have been retrospectively reclassified and are reported in discontinued operations in the accompanying consolidated financial statements. Following is a reconciliation of the major line items comprising loss from discontinued operations for the years ended December 31, 2015 and 2014 : December 31, 2015 December 31, 2014 Revenue $ 2,198,721 $ 1,577,873 Cost of sales $ 2,314,525 $ 1,799,284 Operating expenses $ 1,611,786 $ 1,480,629 Other expenses, net $ 36,708 $ 1,255,738 Pretax loss from discontinued operations $ 1,764,298 $ 2,594,022 Income tax benefit $ 380,176 $ 648,917 Loss from discontinued operations $ 1,384,122 $ 1,945,105 Loss from discontinued operations attributable to noncontrolling interest $ 679,149 $ 745,809 Loss from discontinued operations attributable to American DG Energy Inc. $ 704,973 $ 1,199,296 The total operating and investing cash flows of the discontinued operation for the years ended December 31, 2015 and 2014 are as follows: December 31, 2015 December 31, 2014 Net cash used in operating activities $ (365,186 ) $ (796,024 ) Net cash used in investing activities $ (1,823,847 ) $ (2,843,053 )

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of significant accounting polcies	Summary of significant accounting policies: Principles of Consolidation and Basis of Presentation: The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and include the accounts of the Company and entities in which it has a controlling financial interest. Those entities include the Company's 51.0% joint venture, American DG New York, LLC, or ADGNY, and its 48.0% owned subsidiary EuroSite Power Inc., or EuroSite Power. The interests in underlying energy system projects in ADGNY vary between the Company and its joint venture partner. As the controlling partner, all major decisions in ADGNY are made by the Company according to the joint venture agreement. Distributions, however, are made based on the economic ownership. The economic ownership is calculated by the amount invested by the Company and the noncontrolling partner in each site. Each quarter, the Company calculates a year-to-date profit/loss for each site that is part of ADGNY and the noncontrolling interest percent ownership in each site is applied to determine the noncontrolling interest share in the profit/loss. The Company follows the same calculation regarding available cash and a cash distribution is made to the noncontrolling interest partner each quarter. On the Company’s balance sheet, noncontrolling interest represents the joint venture partner’s investment in ADGNY, plus its share of after tax profits less any cash distributions. The Company owned a controlling 51.0% legal interest and had a 51.0% economic interest in ADGNY as of December 31, 2015 . As of December 31, 2015 and 2014 , the Company owned a 48.0% and a 50.1% , interest in EuroSite Power, respectively, and has consolidated EuroSite Power into its financial statements in both years in accordance with GAAP, as discussed below. The Company has consolidated the operating results and financial position of EuroSite Power as it has determined it has a controlling financial interest in EuroSite Power. This determination was based on application of the variable interest entity (VIE) model which determines whether a controlling financial interest exists by other than majority voting ownership. In applying the VIE model, the Company considered the explicit and implicit variable interests which exist in EuroSite Power including its own and its ability to direct the activities of EuroSite Power which most significantly effect it’s economic performance and the Company’s obligation to absorb the expected losses of EuroSite Power. In addition to its equity ownership in EuroSite Power, the Company has an implicit variable interest in EuroSite Power through its guarantee of the long-term convertible indebtedness of EuroSite Power. This results in the Company’s voting ownership being disproportional to its obligation to absorb the expected losses of EuroSite Power. This combined with the fact that substantially all of EuroSite Power’s activities either involve or are conducted on behalf of the Company results in EuroSite Power being considered a VIE. The Company’s level of ownership results in the Company’s ability to control the activities which most significantly effect the economic performance of EuroSite Power. This combined with the Company’s obligation to absorb losses which could be significant to EuroSite Power qualify the Company as the primary beneficiary of EuroSite Power. As the primary beneficiary of a VIE, the Company is required to consolidate the operating results and financial position of the VIE. The Company provides a guarantee with respect to the outstanding third party convertible indebtedness under EuroSite Power’s convertible debentures which it was not contractually obligated to provide. The Company also helps facilitate and assists EuroSite Power in obtaining additional sources of financing. The Company’s operations are comprised of one business segment. The Company’s business is selling energy in the form of electricity, heat, hot water and cooling to its customers under long-term sales agreements. The Company’s continuing revenue is generated in and the Company's long-lived assets are located in the United States of America. Amounts reflected in these consolidated financial statements as relating to discontinued operations were generated in or are primarily located in the United Kingdom. The Company has experienced total net losses since inception of approximately $40.6 million . For the foreseeable future, the Company expects to experience continuing operating losses and negative cash flows from operations as its management executes the current business plan. The Company believes that its existing resources, including cash and cash equivalents and future cash flow from operations, are sufficient to meet the working capital requirements of its existing business for the foreseeable future, including the next twelve months; however, as the Company continues to grow its business by adding more energy systems, the cash requirements will increase. Beyond December 2, 2017 , the Company may need to raise additional capital through a debt financing or an equity offering to meet its operating and capital needs. There can be no assurance, however, that the Company will be successful in its fundraising efforts or that additional funds will be available on acceptable terms, if at all. If the Company is unable to raise additional capital in 2017 it may need to terminate certain of its employees and adjust its current business plan. Financial considerations may cause the Company to modify planned deployment of new energy systems and may decide to suspend installations until it is able to secure additional working capital. The Company will evaluate possible acquisitions of, or investments in, businesses, technologies and products that are complementary to its business; however, the Company is not currently engaged in such discussions. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Revenue Recognition Revenue from energy contracts is recognized when electricity, heat, and chilled water is produced by the cogeneration systems on-site. The Company bills each month based on various meter readings installed at each site. The amount of energy produced by on-site energy systems is invoiced, as determined by a contractually defined formula. Under certain energy contracts, the customer directly acquires the fuel to power the systems and receives credit for that expense from the Company. The credit is recorded as a cost of sale. Revenues from operations, including shared savings are recorded when provided and verified. Maintenance service revenue is recognized over the term of the agreement and is billed on a monthly basis in arrears. As a byproduct of the energy business, in some cases, the customer may choose to own the energy system rather than have it owned by American DG Energy. In this case, the Company accounts for revenue, or turnkey revenue, and costs using the percentage-of-completion method of accounting. Under the percentage-of-completion method of accounting, revenues are recognized by applying percentages of completion to the total estimated revenues for the respective contracts. Costs are recognized as incurred. The percentages of completion are determined by relating the actual cost of work performed to date to the current estimated total cost at completion of the respective contracts. When the estimate on a contract indicates a loss, the Company records the entire expected loss, regardless of the percentage of completion. The excess of contract costs and profit recognized to date on the percentage-of-completion accounting method in excess of billings is recorded as unbilled revenue. Billings in excess of related costs and estimated earnings is recorded as deferred revenue. Customers may buy out their long-term obligation under energy contracts and purchase the underlying equipment from the Company. Any resulting gain on these transactions is recognized over the payment period in the accompanying consolidated statements of operations. The Company is able to participate in certain energy related programs and receive payments due to the availability of its energy systems. These programs provide incentive payments for either the reduction of electricity usage or the increase in electricity production during periods of peak usage throughout a utility territory. For the years ended December 31, 2015 and 2014 , the revenue recognized by ADGE from these programs was $137,896 and $247,518 , respectively. Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. The Company has cash balances in certain financial institutions in amounts which occasionally exceed current federal deposit insurance limits. The financial stability of these institutions is continually reviewed by senior management. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents. Concentration and Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist of highly liquid cash equivalents and trade receivables. The Company’s cash equivalents are placed with certain financial institutions and issuers. As of December 31, 2015 , the Company had a balance of $3,981,044 in cash and cash equivalents that exceeded the Federal Deposit Insurance Corporation limit. During the years ended December 31, 2015 and 2014 , one customer accounted for 18.0% and 13.0% of revenue, respectively. Accounts Receivable The Company maintains receivable balances primarily with customers located throughout New York, New Jersey and the United Kingdom. The Company reviews its customers’ credit history before extending credit and generally does not require collateral. An allowance for doubtful accounts is established based upon factors surrounding the credit risk of specific customers, historical trends and other information. Generally, such losses have been within management’s expectations. Bad debt is written off against the allowance for doubtful accounts when identified. At December 31, 2015 and 2014 , the allowance for doubtful accounts was $155,000 and $112,000 , respectively. Included in accounts receivable are amounts from four major customers accounting for approximately 45.6% and 31.1% of total accounts receivable as of December 31, 2015 and 2014 , respectively. Inventory Inventories, which consisted of finished goods, are stated at the lower of cost or market, valued on a first-in, first-out basis. Inventory is reviewed periodically for slow-moving and obsolete items. As of December 31, 2015 and 2014 the inventory reserve was $9,750 and $0 , respectively. Supply Concentrations Most of the Company’s cogeneration unit purchases for the years ended December 31, 2015 and 2014 were from one vendor (see “Note 10 - Related parties”). The Company believes there are sufficient alternative vendors available to ensure a constant supply of cogeneration units on comparable terms. However, in the event of a change in suppliers, there could be a delay in obtaining units which could result in a temporary slowdown of installing additional income producing sites. In addition, the majority of the Company’s units are installed and maintained by the noncontrolling interest holder or maintained by Tecogen Inc., or Tecogen (see Note 10 - Related parties). The Company believes there are sufficient alternative vendors available to ensure a constant supply of maintenance and installation services on comparable terms. However, in the event of a change of vendor, there could be a delay in installation or maintenance services. Property and Equipment Property, plant and equipment are stated at cost. Depreciation and amortization are computed using the straight-line method at rates sufficient to write off the cost of the applicable assets over their estimated useful lives. Repairs and maintenance are expensed as incurred. The Company reviews its energy systems for potential impairment whenever events or changes in business circumstances indicate that the carrying value of the assets may not be fully recoverable or that the useful lives of the assets are no longer appropriate. The Company evaluates the recoverability of its long-lived assets when potential impairment is indicated by comparing the remaining net book value of the assets to the estimated future undiscounted cash flows attributable to such assets. The useful life of the Company’s energy systems is the lesser of the economic life of the asset or the term of the underlying contract with the customer, typically 12 to 15 years. If impairment is indicated, the asset is written down to its estimated fair value based on a discounted cash flow analysis. During the years ended December 31, 2015 and 2014 , the Company recorded asset impairment losses totaling $618,661 and $526,766 , respectively, relating to certain of its energy systems as a result of changing or unexpected conditions with respect to the energy systems which impact the estimated future cash flows. The conditional changes impacting the estimated future cash flows related to these assets resulted from changes in the level of demand for electricity and/or hot water at particular installations, finalization of start-up period customization at particular installations and/or price changes in electrical and natural gas rates, all of which impacted estimated future cash flows. The Company receives rebates and incentives from various utility companies and governmental agencies which are accounted for as a reduction in the book value of the assets. The rebates are payable from the utility to the Company and are applied against the cost of construction, therefore reducing the book value of the installation. As a reduction of the facility construction costs, these rebates are treated as an investing activity in the statements of cash flows. The rebates received by the Company from the utilities that apply to the cost of construction are one time rebates based on the installed cost, capacity and thermal efficiency of the installed unit and are earned upon the installation and inspection by the utility and are not related to or subject to adjustment based on the future operating performance of the installed units. The rebate agreements with utilities are based on standard terms and conditions, the most significant being customer eligibility and post-installation work verification by a specific date. During 2015 and 2014 , the amount of rebates applied to the cost of construction was $32,198 and $27,500 , respectively. Stock Based Compensation Stock based compensation cost is measured at the grant date based on the estimated fair value of the award and is recognized as an expense in the consolidated statements of operations over the requisite service period. The fair value of stock options granted is estimated using the Black-Scholes option pricing valuation model. The Company recognizes compensation on a straight-line basis over the expected life for each separately vesting portion of the option award. Use of a valuation model requires management to make certain assumptions with respect to selected model inputs. Expected volatility is calculated based on the Company’s historic volatility over the expected life of the option grant. The average expected life is estimated using the simplified method for “plain vanilla” options. The simplified method determines the expected life in years based on the vesting period and contractual terms as set forth when the award is made. The Company uses the simplified method for awards of stock-based compensation since it does not have the necessary historical exercise and forfeiture data to determine an expected life for stock options. The risk-free interest rate is based on U.S. Treasury zero-coupon issues with a remaining term which approximates the expected life assumed at the date of grant. When options are exercised the Company normally issues new shares. See “Note 7 – Stockholders’ equity” for a summary of the restricted stock and stock option activity under the Company’s stock-based employee compensation plan for the years ended December 31, 2015 and 2014 , respectively. Loss per Common Share The Company computes basic loss per share by dividing net income (loss) for the period by the weighted average number of shares of common stock outstanding during the period. The Company computes diluted earnings per common share using the treasury stock method. For purposes of calculating diluted earnings per share, the Company considers its shares issuable in connection with convertible debentures, stock options and warrants to be dilutive common stock equivalents when the exercise price is less than the average market price of its common stock for the period. For the year ended December 31, 2015 , the Company excluded 14,336,083 anti-dilutive shares resulting from exercise of stock options, warrants and shares issuable in connection with convertible debentures, and for the year ended December 31, 2014 , the Company excluded 15,763,083 anti-dilutive shares resulting from exercise of stock options, warrants and unvested restricted stock. All shares issuable for both years were anti-dilutive because of the reported net loss. Income Taxes As part of the process of preparing its consolidated financial statements, the Company is required to estimate its income taxes in each of the jurisdictions in which it operates. This process involves the Company estimating its actual current tax exposure together with assessing temporary differences resulting from differing treatment of items, such as depreciation and certain accrued liabilities for tax and accounting purposes. These differences result in deferred tax assets and liabilities, which are included within the Company’s consolidated balance sheet. The Company must then assess the likelihood that its deferred tax assets will be recovered from future taxable income and to the extent it believes that recovery is not likely, the Company must establish a valuation allowance. The Company is allowed to recognize the tax benefits of uncertain tax positions only where the position is “more likely than not” to be sustained assuming examination by tax authorities. The amount recognized is the amount that represents the largest amount of tax benefit that is greater than 50.0% likely of being ultimately realized. A liability is recognized for any benefit claimed, or expected to be claimed, in a tax return in excess of the benefit recorded in the financial statements, along with any interest and penalties (if applicable) on that excess. The tax years 2011 through 2014 remain open to examination by major taxing jurisdictions to which the Company is subject, which are primarily in the United States, as carry forward attributes generated in years past may still be adjusted upon examination by the Internal Revenue Service or state tax authorities if they are or will be used in a future period. The Company is currently not under examination by the Internal Revenue Service or any other jurisdiction for any tax years. The Company did not recognize any interest and penalties associated with unrecognized tax benefits in the accompanying consolidated financial statements. The Company would record any such interest and penalties as a component of interest expense. The Company does not expect any material changes to the unrecognized benefits within twelve months of the reporting date. Fair Value of Financial Instruments The Company’s financial instruments are cash and cash equivalents, short-term investments, accounts receivable, investment securities, accounts payable, convertible debentures and amounts due to/from related parties. The recorded values of cash and cash equivalents, accounts receivable, accounts payable and amounts due to/from related parties approximate their fair values based on their short-term nature. The investment securities and warrant liability are recorded at fair value. The carrying value of the convertible debentures and note payable related party on the balance sheet at December 31, 2015 approximates fair value as the terms approximate those currently available for similar instruments. See “Note 11 - Fair value measurements.” Reclassification In our 2014 Consolidated Statement of Cash Flows, certain amounts between Non-cash interest expense and Amortization of convertible debt premium have been reclassified to conform with current year presentation. New Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP and the International Financial Reporting Standards. This guidance supersedes previously issued guidance on revenue recognition and gives a five step process an entity should follow so that the entity recognizes revenue that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This new guidance will be effective for our fiscal 2018 reporting period and must be applied either retrospectively during each prior reporting period presented or retrospectively with the cumulative effect of initially applying this guidance recognized at the date of the initial application. Early adoption is not permitted. We are currently evaluating the impact of the adoption of this ASU on our consolidated financial statements. In August 2014, the FASB issued ASU 2014-15 "Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern". The new standard provides guidance around management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. Early adoption is permitted. The adoption of this ASU is not expected to have a material impact on our consolidated financial statement. In November 2015, the FASB issued ASU 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes" to simplify the presentation of deferred income taxes. Under current GAAP, an entity is required to separate deferred income tax liabilities and assets into current and noncurrent amounts in a classified statement of financial position. The new standard requires deferred tax liabilities and assets to be classified as noncurrent in a classified statement of financial position. The current requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount is not affected by the amendments. The new standard will align the presentation of deferred income tax and liabilities with the International Financial Reporting Standards (IFRS), which requires deferred tax assets and liabilities to be classified as noncurrent in a classified statement of financial position. The amendments take effect for financial statements issued for annual periods beginning after December 15, 2016, and interim periods within those annual periods.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property, plant and equipment	Property and equipment: Property and equipment consist of the following as of December 31, 2015 and 2014 , respectively: 2015 2014 Energy systems $ 23,348,928 $ 25,521,585 Computer equipment and software 143,204 121,958 Furniture and fixtures 85,463 87,051 Vehicles 194,192 226,018 23,771,787 25,956,612 Less — accumulated depreciation (8,822,809 ) (9,124,309 ) 14,948,978 16,832,303 Construction in progress 3,001,809 1,703,947 $ 17,950,787 $ 18,536,250 Depreciation expense of property and equipment totaled $1,776,048 and $1,560,296 for the years ended December 31, 2015 and 2014 , respectively.

ADGNY Reorganization (Notes)

ADGNY Reorganization (Notes)	12 Months Ended
	Dec. 31, 2015
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
ADGNY Reorganization	ADGNY Reorganization: During the second quarter of 2015, the Company entered into an agreement with the noncontrolling interest joint venture partner in ADGNY (the "ADGNY reorganization"), whereby, in exchange for $100,000 cash and 100,000 shares of the Company’s common stock, the noncontrolling interest partner relinquished certain economic interests in certain energy system projects in the joint venture sites owned and operated by ADGNY; ownership of certain energy system projects owned by ADGNY was transferred to the Company; and ownership of certain energy system projects owned by ADGNY was transferred to the noncontrolling interest joint venture partner. Additionally, the interests in underlying energy system projects remaining in ADGNY following the transfers of ownership of those energy system projects in the preceding sentence, were adjusted to 51% and 49% for the Company and the noncontrolling interest joint venture partner, respectively. Following the foregoing series of transactions, the Company retained a controlling 51% legal interest and had a 51% economic interest in ADGNY. The relinquishment by the noncontrolling interest partner of certain economic interests in certain energy system projects in the joint venture sites owned and operated by ADGNY for the benefit of the Company and the adjustment of the respective interests in underlying energy system projects remaining in the joint venture were treated as changes in the Company’s ownership interest in ADGNY while the Company retained a controlling financial interest, and accordingly, were accounted for as equity transactions in accordance with ASC 810-10-45-23. The ADGNY Reorganization resulted in a reduction in additional paid-in capital of $ 732,116 representing primarily the fair value of the energy system projects, cash and Company common stock transferred to the ADGNY joint venture partner. The transfer of ownership of certain energy system projects owned by ADGNY to the noncontrolling interest joint venture partner was treated as a dividend of nonmonetary assets and was recognized at the fair value of the energy systems transferred in accordance with ASC 845-10-30-1, with a gain recognized of $157,870 , which is attributed entirely to the noncontrolling interest in the accompanying statements of operations.

Accrued expenses and other curr

Accrued expenses and other current liabilities (Notes)	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Accrued expenses and other liabilities	Accrued expenses and other liabilities: As of December 31, 2015 and 2014 , accrued expenses and other current liabilities consisted of: 2015 2014 Professional fees accrual $ 147,321 $ 131,078 Payroll accrual 65,101 164,700 Customer deposits 36,525 41,907 Accrued taxes 6,635 4,025 Deferred revenue 2,228 13,608 Total Accrued expenses and other current liabilities $ 257,810 $ 355,318

Convertible debentures

Convertible debentures	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Convertible debentures	Convertible debentures: American DG Energy Convertible Debentures In 2015 and 2014, the Company had issued and outstanding $19,400,000 principal amount of debentures to John N. Hatsopoulos, the Company's Co-Chief Executive Officer, and Principal owners of the Company (the "Senior Unsecured Convertible Debentures"). The debentures, as amended, mature on May 25, 2018 and accrue interest at 6.0% per annum on a semi-annual basis. At the holder's option, the debentures may be converted into shares of the Company's common stock at a conversion price of $2.11 per share, subject to adjustment in certain circumstances. The Company has the option to redeem the debentures at 115% of the Par Value after May 25, 2016. On May 25, 2014, the total interest due to the debenture holders was $582,000 , and the Company satisfied the interest obligation by issuing to the debenture holders 260,154 shares of common stock at $2.24 per share which was the average price of the Company's common stock during the month of April. In connection with this transaction, the Company recorded an additional charge of $42,368 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2014. On October 3, 2014, the Company consummated a series of transactions whereby, under an agreement with John N. Hatsopoulos and a principal owner of the Company, the holders of the Company’s Senior Unsecured Convertible Debentures paid the interest due under the convertible debentures through the next semiannual payment date of November 25, 2014 by delivering 1,164,000 shares of common stock of its former subsidiary EuroSite Power, which were owned by the Company and which had a market value of $582,000 . The Company also delivered 8,245,000 additional shares of EuroSite Power it owned with an aggregate market value of $4,122,500 to the holders of the Senior Unsecured Convertible Debentures for prepayment of all interest which would become due under the Senior Unsecured Convertible Debentures through the maturity date of May 25, 2018. In connection with these transactions, the Company delivered to the holders of the Senior Unsecured Convertible Debentures three -year warrants with an exercise price per share of $0.60 to purchase an additional 1,164,000 shares of EuroSite Power from the Company with an aggregate market value of $84,911 . These transactions are reciprocal transfers and thus exchanges of non-monetary assets which are accounted for at fair value. The fair value recognized in recording the exchanges equaled the fair market value of the EuroSite Power shares relinquished and the amount of cash the counterparties to the exchange could have received in cash in lieu of accepting the shares, which amounts were identical with the exception of the additional value ascribed to the warrants of $84,911 . No gain or loss was recognized relative to these transactions under ASC 810-10-45-23 since the Company retained a controlling financial interest in EuroSite Power following these transactions. Accordingly, these transactions were accounted for as equity transactions with any difference between the fair value assigned and the necessary adjustment to noncontrolling interest being assigned to the additional paid-in capital of the Company. Following the payment of all current and future interest under the convertible debentures, the Company exchanged the Senior Unsecured Convertible Debentures which bore interest at an annual rate of 6% for non-interest bearing convertible debentures ("2014 Senior Unsecured Convertible Debentures"), the 2014 Convertible Debentures, with all other terms including the principal amount, maturity date, and conversion terms and privileges remaining unchanged. The exchange of debentures was not considered to be an extinguishment under ASC 470-50 as the debt instruments exchanged were not considered to have substantially different terms and, accordingly, no gain or loss was recognized. The existing basis in the convertible debentures prior to the exchange was carried over and an additional discount equal to the fair value of the EuroSite Power shares exchanged for future interest and the fair value of the warrants was recorded. The total discount, including the fair value of the warrant of $84,911 , was $4,207,411 . The revised discount is being amortized to interest expense on the interest method. The effective interest rates to fully accrete the 2014 Convertible Debentures to their face value at maturity is 7.8% . The unamortized discount at December 31, 2015 and 2014 was $3,321,088 and $4,523,051 , respectively. The non-cash interest expense related to amortization of the discount in the year ended December 31, 2015 and 2014 was $1,191,333 and $162,486 , respectively. Eurosite Power Convertible Debentures On February 26, 2013, EuroSite Power issued a promissory note in the amount of $1,100,000 to the Company. Under the terms of the agreement EuroSite Power was to pay interest at a rate of 6.0% per annum payable quarterly in arrears. On June 14, 2013, EuroSite Power entered into subscription agreements with certain investors, including the Company, for a private placement of an aggregate principal amount of $4,000,000 of 4% Senior Unsecured Convertible Notes Due 2015, or the Notes. In connection with the private placement, the Company exchanged the promissory note in the aggregate principal amount of $1,100,000 , originally issued on February 26, 2013 (the "Old Note") for a like principal amount of the Notes and cash paid for any accrued but unpaid interest on the Old Note. The holders of the Notes are subject to and entitled to the benefits of the 4% Senior Convertible Notes due 2015 Noteholders Agreement, dated June 14, 2013, or the Noteholders Agreement. The Notes were to mature on June 14, 2015 and accrue interest at the rate of 4% per annum payable in cash on a semi-annual basis. At the Investor's option, the Notes may be converted into shares of EuroSite Power's common stock at an initial conversion rate of 1,000 shares of common stock per $1,000 principal amount of Notes, subject to adjustment. At the scheduled maturity date, each of the Investors have the following options: request payment of their principal amount and accrued interest in cash; extend the term of the Notes for an additional 3 years with an automatic decrease in interest rate to 3% per annum; or exchange the Notes for a new non-convertible note with a 3 -year maturity and a 6% per annum interest rate; no accrued interest will be lost on such exchange. EuroSite Power evaluated the term-extending option and concluded that it was an embedded derivative with de minimis value. The Company has subsequently concluded that it is not considered a derivative under ASC 815-Derivatives and Hedging because the term extending feature is considered clearly and closely related to the Notes. Thus, this feature was not required to be bifurcated and no other initial accounting was required. The term-extending option has subsequently been eliminated pursuant to the note exchange agreements discussed herein. The Notes are guaranteed on a subordinated basis by American DG Energy. The Noteholders Agreement provides for customary events of default by EuroSite Power, including failure to pay interest within ten days of becoming due, failure to pay principal when due, failure to comply provisions of the Notes or the Noteholders Agreement, subject to cure, and certain events of bankruptcy or insolvency. The holders of the Notes are entitled to the benefits of a registration rights agreement dated June 14, 2013 by and among EuroSite Power and the Noteholders named therein, or the Registration Rights Agreement. The Registration Rights Agreement provides for demand registration rights, such that upon the demand of 30% of the holders of Registrable Securities, as defined in the Registration Rights Agreement and subject to certain conditions (including that EuroSite Power is eligible to use a Form S-3 registration statement and that such holders anticipate an aggregate offering price, net of selling expenses, of at least $250,000 ), EuroSite Power will file a Form S-3 registration statement covering the Registrable Securities requested to be included in such registration, subject to adjustment. Included among the investors exchanging their Notes for New Notes were: the Company, in the amount of $1,100,000 ; Bruno Meier, a director of EuroSite Power, in the amount of $250,000 ; Prime World Inc., a company controlled by Joan Giacinti, one of the Company's directors, in the amount of $300,000 ; Charles T. Maxwell, Chairman of the Board of Directors of the Company, in the amount of $250,000 ; Nettlestone Enterprises Limited, a shareholder of both EuroSite Power and the Company, in the amount of $300,000 ; Perastra Management S.A., an investor in the Company and EuroSite Power, in the amount of $1,500,000 ; and Yves Micheli, an investor in EuroSite Power, in the amount of $300,000 . On February 20, 2014, EuroSite Power accepted certain separate note exchange agreements, or the Note Exchange Agreements, from the holders of the Notes, pursuant to which EuroSite Power exchanged the Notes for like principal amounts of 4% Senior Convertible Notes Due 2017, or the New Notes, in an aggregate principal amount of $4,000,000 . Accrued but unpaid interest on the Notes was treated as accrued interest under the New Notes. The effect of the Note Exchange agreement (a) extended the maturity date from June 14, 2015 to June 14, 2017, (b) adjusted the conversion price of the notes which changed from 1,000 shares of EuroSite Power's common stock for each $1,000 of principal converted to 1,667 shares of EuroSite Power’s common stock for each $1,000 of principal converted, and (c) eliminated the Holders’ options to extend the Notes. The Company analyzed the impact of the Note Exchange Agreement and determined that the Notes and the New Notes were substantially different and, as a result, EuroSite Power recognized a loss on extinguishment of $713,577 to recognize the excess of the fair value of the New Notes that were issued in the exchange over the carrying value of the Notes surrendered, of which, $180,400 related to the Company's holdings and was eliminated in consolidation. The New Notes were recorded at fair value as of the date of the exchange with the difference between the fair value of the debt of $4,656,000 and the carrying value of $4,000,000 , or $656,000 , being recorded as a premium. The portion of the $656,000 premium attributable to the Company's holdings, or $180,400 , is eliminated in consolidation. The interest method of accounting is used to amortize the premium over the life of the New Notes. The fair value of the New Notes was determined using a binomial lattice model. The following table provides quantitative information used in the fair value measurement, including the assumptions for the significant unobservable inputs used in the binomial lattice model valuation: Notional amount $ 4,000,000 Par amount $ 1,000 Interest rate 4.0 Conversion ratio 1,667 Conversion price, per share $ 0.60 Stock price as of the valuation date $ 0.51 Historical realized weekly volatility 87 % Risk free rate 0.9 % Discrete dividend payment rate — % Significant increases (decreases) in the significant unobservable inputs used in the fair value measurement of the New Notes would result in a significantly higher (lower) fair value measurement. Effective April 15, 2014 and April 24, 2014 EuroSite Power, entered into a subscription agreements with John N. Hatsopoulos, the chairman of the Company's Board of Directors, certain other investors and a principal owner of the Company for the sale of a $1,450,000 , 4% Senior Convertible Note Due 2018 (the "2014 Notes"). The 2014 Notes will mature in four years and will accrue interest at the rate of 4% per annum payable on a semi-annual basis. At the holder’s option, the 2014 Notes may be converted into shares of the EuroSite Power’s common stock at a conversion price of $0.60 per share, subject to adjustment in certain circumstances. The proceeds of the 2014 Notes will be used in connection with the development and installation of current and new energy systems, business development and for general corporate purposes. On October 3, 2014, EuroSite Power entered into convertible note amendment agreements, or the Note Amendment Agreements, with the Company, John N. Hatsopoulos and principal owner of the Company, as well as certain separate convertible note conversion agreements, or the Note Conversion Agreements, with certain other investors, which eliminated $3,050,000 of EuroSite Power's convertible notes. Among other things, the Note Amendment Agreements provided for the conversion, in full, of the principal amount of certain of the New Notes and the 2014 Notes or collectively, the Converted Notes, in an aggregate principal amount of $3,050,000 , pursuant to which the holders of such Converted Notes, or the Holders, agreed to convert, in full, the principal amount of the Converted Notes. In connection with the conversion, the Converted Notes were cancelled and the Holders were issued 6,100,000 shares of EuroSite Power’s common stock at a conversion price of $.50 per share, with any accrued but unpaid interest to be paid in cash. The conversion price of $.50 per share was less than the $.60 per share that was contractually provided for on the convertible debentures. Accordingly, in accordance with ASC 470-20-40, this transaction was accounted for as an inducement conversion with the fair value of the incremental shares issued being recognized as an expense. On a consolidated basis after elimination of intercompany items, the expense recognized was $324,977 . The unamortized premium was $136,422 at December 31, 2015 and non-cash interest income related to amortization of the premium for the year-ended December 31, 2015 was $96,288 , which was net with interest expense. The Company guarantees (the “Guarantees”), the remaining Notes on a subordinated basis. Among other things, the Guarantees provide that, in the event of EuroSite Power's failure to pay principal or interest on a Note, the holder of such Note, on the terms and conditions set forth in the Notes, may proceed directly against the Company, as guarantor, to enforce the Guarantee. These securities were offered and sold to the investors in private placement transactions made in reliance upon exemptions from registration pursuant to Section 4(a)(2) under the Securities Act of 1933 and Rule 506 promulgated thereunder. The investors are accredited investors as defined in Rule 501 of Regulation D promulgated under the Securities Act of 1933. The face amount of convertible debentures and the related premium or discount are as follows as of December 31, 2015 and 2014, respectively: 2015 American DG Energy EuroSite Power Total Face amount $ 19,400,000 $ 2,400,000 $ 21,800,000 Premium (discount) (3,321,088 ) 136,422 (3,184,666 ) 16,078,912 2,536,422 18,615,334 Less amounts due to related parties (16,078,912 ) (951,158 ) (17,030,070 ) $ — $ 1,585,264 $ 1,585,264 2014 American DG Energy EuroSite Power Total Face amount $ 19,400,000 $ 2,400,000 $ 21,800,000 Premium (discount) (4,523,051 ) 232,710 (4,290,341 ) 14,876,949 2,632,710 17,509,659 Less amounts due to related parties (14,876,949 ) (987,266 ) (15,864,215 ) $ — $ 1,645,444 $ 1,645,444

Stockholders' equity

Stockholders' equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' equity	Stockholders’ equity: EuroSite Power - Note Payable - Related Party On September 19, 2014, John Hatsopoulos loaned EuroSite Power $3,000,000 without interest pursuant to a promissory note (the "Loan"). The Loan matures upon a substantial capital raise or on September 19, 2019. Prepayment of principal may be made at any time without penalty. The proceeds of the Loan will be used in connection with the development and installation of current and new energy systems in the United Kingdom and Europe. On December 30, 2014, the EuroSite Power amended and restated the existing promissory note to provide for interest at a rate of 1.85% . During 2015 the EuroSite made a prepayment of $1,000,000 on this note. As of December 31, 2015, the outstanding balance on this Loan is $2,000,000 plus accrued interest of approximately $28,000 . Common Stock On August 6, 2014, the Company entered into an underwritten offering with an underwriter whereby the Company issued: (i) 2,650,000 shares of its common stock, (ii) three -year warrants to purchase up to 2,829,732 shares of its common stock and five -year warrants to purchase an additional 112,538 to the underwriters with an exercise price of $1.89 per share and net proceeds of $3,269,275 . The Company continues to use the net proceeds of the offering for working capital purposes in connection with development and installation of current and new energy systems. On September 19, 2014, the Board of Directors of the Company approved a common stock repurchase program that shall not exceed 1,000,000 shares of common stock and shall not exceed $1,100,000 of cost. The approval allows for purchases over a 24 -month period at prices not to exceed $1.30 per share. During the year ended December 31, 2015, the Company repurchased 235,906 shares of common stock at an average price of $0.55 . During the year ended December 31, 2014, the Company repurchased 588,073 shares of common stock at an average price of $0.80 . On January 29, 2015, the Company entered into an exchange agreement, (or the "Exchange Agreement"), with IN Holdings Corp., (or "IN Holdings"), a holder of more than 5% percent of the Company’s common stock. In connection with the Exchange Agreement, IN Holdings transferred to the Company 1,320,000 shares of the Company’s common stock that it owned, and in exchange, the Company transferred to IN Holdings 1,320,000 shares of the common stock of EuroSite Power Inc. that it owned. The exchange was accounted for as an acquisition and retirement of treasury shares and a disposal of partial ownership of a former consolidated subsidiary. As the Company retained a controlling financial interest following the exchange, no gain or loss was recognized on the disposal in accordance with ASC 810-10-45-23. In accordance with ASC 845-10-05-4, nonmonetary transactions, the impact of the share exchange was a credit to the par value of the common stock of $1,320 and the net impact on non-controlling interest was $16,570 . "In conjunction with the ADGNY Reorganization (see Note 4), the Company issued 100,000 shares with a fair value of $63,000 . The holders of common stock have the right to vote their interest on a per share basis. At December 31, 2015 , there were 50,684,095 shares of common stock outstanding. Warrants Other than as noted in Common Stock above, the Company issued no warrants in the years ended December 31, 2015 and 2014 . Warrant activity for the years ended December 31, 2015 and 2014 was as follows: Number of Warrants Weighted Average Exercise Price Balance, December 31, 2013 507,500 $ 3.24 Granted 2,942,270 1.89 Exercised — — Expired — — Balance, December 31, 2014 3,449,770 $ 2.09 Granted — — Exercised — — Expired (500,000 ) 3.25 Balance, December 31, 2015 2,949,770 $ 1.89 Stock Based Compensation – American DG Energy American DG has adopted the 2005 Stock Incentive Plan, or the Plan, under which the board of directors may grant incentive or non-qualified stock options and stock grants to key employees, directors, advisors and consultants of American DG. The maximum number of shares of stock allowable for issuance under the Amended Plan is 8,000,000 shares of common stock. Stock options vest based upon the terms within the individual option grants, usually over a four - or ten -year period with an acceleration of the unvested portion of such options upon a liquidity event, as defined in American DG’s stock option agreement. The options are not transferable except by will or domestic relations order. The option price per share under the Amended Plan is not less than the fair market value of the shares on the date of the grant. During the years ended December 31, 2015 and 2014 , American DG recognized employee non-cash compensation expense of $222,128 and $310,900 , respectively. At December 31, 2015 , the total compensation cost related to unvested stock option awards not yet recognized is $212,575 . This amount will be recognized over the weighted average period of 2.5 years . In 2014 , American DG granted 20,000 nonqualified options to purchase shares of its common stock to a director and 1,049,000 to two employees at prices ranging between $0.52 and $2.18 per share. Those options have a vesting schedule of 4 years and 280,000 of them expire in 10 years while 150,000 expire in 5 years . The fair value of all options issued in 2014 was $678,570 , with a weighted average grant date fair value of $0.63 per option. In 2015 , American DG granted 200,000 nonqualified options to purchase shares of its common stock to two officers of the Company at prices ranging between $0.29 and $0.52 per share. Those options have a vesting schedule of 4 years and expire in 10 years. The fair value of the options issued in 2015 was $53,195 , with a weighted average grant date fair value of $0.27 per option. The weighted average assumptions used in the Black-Scholes option pricing model are as follows: 2015 2014 Stock options and restricted stock awards Expected life 6.25 years 6.25 years Risk-free interest rate 2.09 % 2.03 % Expected volatility 72.90 % 68.80 % Stock option activity for the year ended December 31, 2015 was as follows: Common Stock Options Number of Options Weighted Average Exercise Price Weighted Average Remaining Life Aggregate Intrinsic Value Outstanding, December 31, 2014 3,119,000 $1.32 5.15 years $ 25,600 Granted 200,000 $0.41 Exercised — — Canceled (535,000 ) $1.42 Expired (306,000 ) $2.59 Outstanding, December 31, 2015 2,478,000 $1.06 4.93 years $ 4,000 Exercisable, December 31, 2015 1,308,000 $1.22 $ — Vested and expected to vest, December 31, 2015 2,478,000 $1.06 $ 4,000 The aggregate intrinsic value of options outstanding as of December 31, 2015 is calculated as the difference between the exercise price of the underlying options and the price of American DG’s common stock for options that were in-the-money as of that date. Options that were not in-the-money as of that date, and therefore have a negative intrinsic value, have been excluded from this amount. Stock-Based Compensation – EuroSite Power EuroSite Power has adopted the 2011 Stock Incentive Plan, or the Plan, as amended, under which their Board of Directors may grant up to 4,500,000 shares of incentive or non-qualified stock options and stock grants to key employees, directors, advisors and consultants of EuroSite Power. Stock options vest based upon the terms within the individual option grants, usually over a four year period with an acceleration of the unvested portion of such options upon a liquidity event, as defined in EuroSite Power’s stock option agreement. The options are not transferable except by will or domestic relations order. The option price per share under the Amended Plan is not less than the fair value of the shares on the date of the grant. The number of securities remaining available for future issuance under the Amended Plan was 390,000 at December 31, 2015 . During 2014, the Company granted 520,000 options with a weighted average exercise price of $0.65 , exercise prices between $0.40 and $0.89 , vesting schedules of 4 years and expiration in 10 years. The assumptions used in Black-Scholes option pricing model included an expected life of 6.25 years, a weighted average risk-free interest rate of 2.1% and a weighted average expected volatility of 34.4% . The weighted average grant date fair value of all grants in 2014 was $0.25 and the total fair value of all grants was $129,083 . Of the options granted in 2014, 220,000 were granted to an officer with an exercise price of $0.89 and the Black-Scholes option pricing model assumptions included an expected life of 6.25 years, a risk-free interest rate of 2.18% and an expected volatility of 35.1% , leading to a total fair value of $75,358 . In addition, during 2014, 200,000 options were granted to an executive with an exercise price of $0.52 and the Black-Scholes option pricing model assumptions included an expected life of 6.25 years, a risk-free interest rate of 2.02% and an expected volatility of 34.9% , leading to a total fair value of $39,530 . The remaining 100,000 options granted during 2014 were granted to an executive with an exercise price of $0.40 and the Black-Scholes option pricing model assumptions included an expected life of 6.25 years, a risk-free interest rate of 2.11% and an expected volatility of 31.7% , leading to a total fair value of $14,194 . During 2015, the Company granted 400,000 options with an exercise price of $0.70 , vesting schedules of 4 years and expiration in 10 years. The assumptions used in the Black-Scholes option pricing model included an expected life of 6.25 years, a weighted average risk-free interest rate of 2.1% and a weighted average expected volatility of 31.08% . The weighted average grant date fair value of all grants in 2015 was $0.24 and the total fair value of all grants was $96,220 . Of the options granted in 2015, 375,000 were granted to executives of the company and 25,000 to an employee. At December 31, 2015 , EuroSite Power had 4,110,000 options outstanding and recognized employee non-cash compensation expense of $77,059 related to the issuance of those stock options. For the year ended December 31, 2015 the total compensation cost related to unvested stock option awards not yet recognized was $90,202 . This amount will be recognized over the weighted average period of 2.94 years . Stock option activity for the year ended December 31, 2015 was as follows: Common Stock Options Number of Options Weighted Average Exercise Price Weighted Average Remaining Life Aggregate Intrinsic Value Outstanding, December 31, 2014 4,305,000 $0.87 6.84 years $ 9,800 Granted 400,000 $0.70 Exercised — — Canceled (595,000 ) $0.88 Expired — — Outstanding, December 31, 2015 4,110,000 $0.84 6.06 years $ 410,500 Exercisable, December 31, 2015 3,442,500 $0.89 $ 208,125 Vested and expected to vest, December 31, 2015 4,110,000 $0.84 $ 410,500 The aggregate intrinsic value of options outstanding as of December 31, 2015 is calculated as the difference between the exercise price of the underlying options and the price of EuroSite Power’s common stock for options that were in-the-money as of that date. Options that were not in-the-money as of that date, and therefore have a negative intrinsic value, have been excluded from this amount. During the years ended December 31, 2015 and 2014 , the American DG Energy recognized employee non-cash compensation expense of $222,130 and $310,900 , respectively, related to the issuance of stock options by the Company. At December 31, 2015 and 2014 , the total compensation cost related to unvested stock option awards, for American DG Energy, not yet recognized was $212,575 and $696,870 , respectively. Noncontrolling interests The following schedule discloses the effects of changes in the Company's ownership interest in its consolidated subsidiaries and former consolidated subsidiaries on the Company's equity for the years ended December 31, 2015 and 2014 . 2015 2014 Loss attributable to American DG Energy Inc. $ (5,430,403 ) $ (5,888,894 ) Transfers (to) from noncontrolling interest: Decrease in additional paid-in capital for exchange of 1,320,000 EuroSite Power common shares for current and future interest related to the Company's convertible debentures (see "Note 6 - Convertible debentures") (15,250 ) Reorganization of subsidiary ownership (See "Note 7 - Stockholders' equity") (732,116 ) Increase in additional paid-in capital for exchange of 9,409,000 EuroSite Power common shares for current and future interest related to the Company's convertible debentures (see "Note 6 - Convertible debentures") 4,704,500 Increase in additional paid-in-capital for sale by EuroSite Power of 3,000,000 common shares and warrants 1,486,329 Decrease in additional paid-in-capital for reacquisition by EuroSite Power of 100,000 of its common shares (42,902 ) Increase in additional paid-in-capital for conversion of EuroSite Power convertible debentures into 6,100,000 common shares of EuroSite Power 2,455,377 Noncontrolling interest share of transactions affecting subsidiary ownership 426,980 (2,718,159 ) Subtotal transfers (to) from noncontrolling interest (320,386 ) 5,885,145 Change from net loss attributable to American DG Energy Inc. and transfers (to) from noncontrolling interest $ (5,750,789 ) $ (3,749 )

Warrant liability

Warrant liability	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Warrant liability	Warrant liability: In connection with a subscription agreement that the Company entered into on December 9, 2010, the Company issued warrants for the purchase of 500,000 shares of its common stock. The warrants have an exercise price of $3.25 and are exercisable for five years , commencing six months after the closing of the offering and expired on December 14, 2015 . The warrants contain both a right to obtain stock upon exercise, or a Call, and a right to settle the warrants for cash upon the occurrence of certain events, or a Put. Generally, the Put provisions allow the warrant holders liquidity protection; the right to receive cash equal to the value of the remaining unexercised portion of the warrants in certain situations where the holders would not have a means of readily selling the shares issuable upon exercise of the warrants (e.g., where there would no longer be a significant public market for the Company’s common stock). Specifically, the Put rights would be triggered upon the occurrence of a Fundamental Transaction as defined in the agreement. Pursuant to the agreement, in the case of a Fundamental Transaction the warrant holders would receive a cash settlement in an amount equal to the value of obtained by using the Black Scholes Option Pricing Model obtained from the “OV” function on Bloomberg L.P. using (i) a price per share of Common Stock equal to the Volume-Weighted Average Price of the Common Stock for the Trading Day immediately preceding the date of consummation of the applicable Fundamental Transaction, (ii) a risk-free interest rate corresponding to the U.S. Treasury rate for a period equal to the remaining term of this Warrant as of the date of consummation of the applicable Fundamental Transaction and (iii) an expected volatility equal to the lesser of (1) the thirty ( 30 ) day volatility obtained from the “HVT” function on Bloomberg L.P. determined as of the end of the Trading Day immediately following the public announcement of the applicable Fundamental Transaction or (2) 70% . These warrants are classified as liabilities pursuant to the FASB guidance contained in ASC 480. Changes in the fair value of the warrant liabilities are recorded in the accompanying statements of operations (see “Note 11 – Fair value measurements”).

Employee benefit plan

Employee benefit plan	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee benefit plan	Employee benefit plan: The Company has a defined contribution retirement plan, or the Retirement Plan, which qualifies under Section 401(k) of the Internal Revenue Code, or the IRC. Under the Retirement Plan, employees meeting certain requirements may elect to contribute a percentage of their salary up to the maximum allowed by the IRC. The Company matches a variable amount based on participant contributions up to a maximum of 4.50% of each participant’s salary. The Company contributed $52,469 and $49,816 to the Retirement Plan for the years ended December 31, 2015 and 2014 , respectively.

Related parties

Related parties	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related parties	Related parties: Eurosite Power, Tecogen, Ilios Inc., or Ilios are affiliated companies by virtue of common ownership. The Company purchases the majority of its cogeneration units from Tecogen, an affiliate Company sharing similar ownership. In addition, Tecogen pays certain operating expenses, including benefits and payroll, on behalf of the Company and the Company leases office space from Tecogen. These costs were reimbursed by the Company. For years ending December 31, 2015 and 2014 , the Company bought equipment and maintenance services from Tecogen of $1,956,731 and $1,432,801 , respectively. In July 2012, the Company entered into a Facilities, Support Services and Business Agreement, or the Agreement, with Tecogen, to provide the Company with certain office and business support services for a period of one year , renewable annually by mutual agreement. Under the current amendment to the Agreement, Tecogen provides the Company with office space and utilities at a monthly rate of $5,122 . On July 1, 2013 and November 12, 2013, the Company entered into an Amendments with Tecogen. The Amendments renews the term of the Facilities, Support Services and Business Agreement between the Company and Tecogen. The Amendments further clarifies that the total sales thresholds for volume discounts are to be met during a calendar year and that the Company's representation rights may be terminated by either the Company or Tecogen upon 60 days' notice, without cause. The Amendments state that in New England States the Company shall have the right to purchase Cogeneration products directly from Tecogen as described in the agreement so long as the Company intended use is it to retain long-term ownership of the Cogeneration product and utilize it for the production and sale of electricity and thermal energy. Tecogen will not sell its products to parties for which the intended use is to earn revenue from metered energy to third parties (i.e., ADG Energy “On-Site Utility” energy projects) other than the Company. In cases where the Company has the opportunity to sell Cogeneration products to an unaffiliated party in the New England States and where Tecogen has no other appointed representation in that specific region, the Company may buy/resell the Cogeneration product as specified under the terms of this agreement. If, however, Tecogen has appointed a local exclusive representative in that specific New England region, The Company will defer to the local representative for pricing and other specific details for working cooperatively. The Company has granted Tecogen sales representation rights on its On-Site Utility energy service in California. On October 22, 2009, the Company signed a five -year exclusive distribution agreement with Ilios Inc., or Ilios, a subsidiary of Tecogen. Under terms of the agreement, the Company has exclusive rights to incorporate Ilios’ ultra-high-efficiency heating products, such as a high efficiency water heater, in its energy systems throughout the European Union and New England. The Company also has non-exclusive rights to distribute Ilios’ product in the remaining parts of the United States and the world in cases where the Company retains ownership of the equipment for its On-Site Utility business. On November 12, 2013, the Company entered into the First Amendment to the Sales Representative Agreement with Ilios. The Amendment allows Ilios to appoint sales representatives in the European Union (EU) in addition to the Company. For nations of the EU the company has the right under this agreement to purchase Ilios products directly from Ilios at a stipulated price as long as the Company's intended use is to retain long-term ownership of the Ilios product and utilize it for the production and sale of thermal energy (i.e., ADG Energy/EuroSite Power “On-Site Utility” energy projects). Ilios will not sell its products to parties for which the intended use is to earn revenue from metered energy to third parties (i.e., ADG Energy/EuroSite Power “On-Site Utility” energy projects) other than the Company. In cases where the Company has the opportunity to sell Ilios product to an unaffiliated party in the EU and where Ilios has no other appointed representation in that specific region, the Company may buy/resell the Ilios product as specified under the terms of this contact. If, however, Ilios has appointed a local exclusive representative in that specific EU region, the Company will defer to the local representative for pricing and other specific details for working cooperatively. On July 7, 2015, the EuroSite Power entered into a Revolving Line of Credit Agreement, or the Agreement, with Elias Samaras, EuroSite's Chief Executive Officer, President, and a member of the Company's board of directors. Under the terms of the Agreement, Mr. Samaras has agreed to lend EuroSite up to an aggregate of $1 million , at the written request of EuroSite. Any amounts borrowed by the EuroSite pursuant to the Agreement will bear interest at 6% per year. Interest is due and payable quarterly in arrears. The term of the Agreement is from June 30, 2015 to June 30, 2017. Repayment of the principal amount borrowed pursuant to the Agreement will be due on June 30, 2017, or the Maturity Date. Prepayment of any amounts due under the Agreement may be made at any time without penalty. The Agreement terminates on the Maturity Date. EuroSite has not yet borrowed any amounts pursuant to the Agreement. For a description of related party transactions see Note 6 "Convertible debentures".

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements: The fair value topic of the FASB Accounting Standards Codification defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The accounting guidance also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value: Level 1 — Unadjusted quoted prices in active markets for identical assets or liabilities. The Company currently does not have any Level 1 financial assets or liabilities. Level 2 — Observable inputs other than quoted prices included in Level 1. Level 2 inputs include quoted prices for identical assets or liabilities in non-active markets, quoted prices for similar assets or liabilities in active markets and inputs other than quoted prices that are observable for substantially the full term of the asset or liability. The Company considers its convertible debentures a level 2 liability and believes that its carrying value approximates fair value. Level 3 — Unobservable inputs reflecting management’s own assumptions about the input used in pricing the asset or liability. As of December 31, 2014 , the Company has classified the warrants with put and call rights as Level 3 (see “Note 8 – Warrant liability”). The Company estimated that the fair value of the warrants using a Black-Scholes option pricing model under various probability-weighted outcomes which take into consideration the protective, but limited, cash-settlement feature of the warrants. At issuance, the following average assumptions were assigned to the varying outcomes: expected volatility of 57.0% , risk free interest rate of 2.08% , expected life of five years and no dividends. On December 14, 2015, these warrants expired and, therefore, have no value as of December 31, 2015 . The following table summarizes the warrant activity for the period: Warrant Liabilities Fair value at December 31, 2014 $ 6,780 Fair value adjustment at December 14, 2015 (6,780 ) Fair value at December 31, 2015 $ — In connection with the Company’s asset impairment analysis (see Note 2 - Summary of significant accounting policies - Property and equipment), the Company utilized Level 3 category fair value measurements. Those measurements employed the use of discounted cash flow analysis to determine the fair value of certain energy systems. The discounted cash flow analyses were based on estimates of the future profitability of each energy system based on existing specifically identifiable contractual provisions related to each energy system and a discounted at a rate of 5.61% per annum. In connection with the ADGNY reorganization (see Note 4 - ADGNY reorganization), the Company utilized Level 3 category fair value measurements to account for the assets transferred to AES-NJ. Those measurements employed the use of discounted cash flow analysis to determine the fair value of certain energy systems. The discounted cash flow analyses were based on estimates of the future profitability of each energy system based on existing specifically identifiable contractual provisions related to each energy system and a discounted at a rate of 15% per annum or $632,016 and a book value of $474,146 with a resultant gain of $ 157,870 .

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income taxes	Income taxes: The components of loss from operations for both continuing and discontinued operations before income taxes for the years ended December 31, 2015 and 2014 are as follows: 2015 2014 Domestic $ (4,731,000 ) $ (5,310,000 ) Foreign (1,304,000 ) (1,224,000 ) $ (6,035,000 ) $ (6,534,000 ) EuroSite Power's amounts are included in discontinued operations on the Statements of Operations. Reconciliation of federal statutory income tax provision to the Company’s actual provision for the years ended December 31, 2015 and 2014 , respectively, are as follows, including a provision of $27,605 and $3,877 for American DG and a benefit of $380,176 and $648,917 for EuroSite Power: 2015 2014 Benefit at federal statutory tax rate $ (2,052,000 ) $ (2,222,000 ) Foreign rate differential 209,000 159,000 UK Energy Incentives (380,000 ) (649,000 ) Unbenefited operating losses 1,843,000 2,063,000 Provision for income taxes 37,000 4,000 Income tax provision $ (343,000 ) $ (645,000 ) The component of net deferred tax assets recognized in the accompanying balance sheets at December 31, 2015 and 2014 , respectively, are as follows: 2015 2014 Net operating loss carryforwards $ 11,875,000 $ 10,838,000 Accrued expenses and other 57,000 100,000 Stock compensation 1,312,000 1,194,000 Depreciation 357,000 (216,000 ) 13,601,000 11,916,000 Valuation allowance (13,601,000 ) (11,916,000 ) Net deferred tax asset $ — $ — As of December 31, 2015 , the Company and its former subsidiary, EuroSite Power has federal and state loss carryforwards of approximately $27,258,000 and $25,646,000 , respectively, which may be used to offset future federal and state taxable income, expiring at various dates through 2035. Included in these net operating losses is $1,353,000 of excess stock compensation deductions, related to the amount of tax deductions on restricted stock, in excess of book compensation expense. As of December 31, 2015 , the Company also has foreign loss carryforwards of approximately $4,734,000 which may be used to offset future foreign taxable income. Management has determined that it is more likely than not that the Company will not recognize the benefits of the federal and state deferred tax assets and as a result has recorded a valuation allowance against the entire net deferred tax asset. If the Company should generate sustained future taxable income, against which these tax attributes may be recognized, some portion or all of the valuation allowance would be reversed. The valuation allowance increased by 1,685,000 during the year ended December 31, 2015 , due primarily to net operating losses generated, stock compensation and depreciation. The valuation allowance increased $1,316,000 during the year ended December 31, 2014 , due primarily to net operating losses generated, stock compensation and depreciation. T he Company files income tax returns in U.S. federal jurisdiction and a foreign jurisdictions. The IRS can audit for the years 2011 through 2014. The IRS has the ability to audit the deduction for net operating losses in the year taken. We do not have an IRS audit underway at this time. In the UK, we are open for audit by Her Majesty Revenue and Customs, or HMRC, for the years 2013 through 2014. We do not have an HMRC audit underway at this time. The Company has no uncertain tax positions as of December 31, 2015 and 2014 . The Company joins in the filing of a state unitary return with its former subsidiary, EuroSite Power, Inc. During the years ended December 31, 2015 and 2014 , the Company recognized an United Kingdom energy tax incentive benefit of $377,988 and $636,661 for "Advanced Capital Allowances" (ECA), whereby the Company will receive a cash benefit that is an acceleration of tax relief on capital expenditures of co-generation equipment put into service at approved sites in the UK. These amounts are included in discontinued operations. The Company's federal and state net operating losses could be limited to the extent that there are significant changes in ownership of the Company's stock. The company has not assessed the impacts of these limitations on its tax attributes.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies: On July 1, 2013, the Company entered into an Amendment to the Facilities, Support Services and Business Agreement, or the Amendment, with Tecogen. The Amendment renews the term of the Facilities, Support Services and Business Agreement between the Company and Tecogen for a one -year period, beginning on July 1, 2013. The Amendment also decreases the space provided to the Company by Tecogen from approximately 3,282 square feet to 2,400 square feet. Under the Amendment, the amount that the Company will pay Tecogen for the space and services that Tecogen provides under the Agreement decreased to $5,122 per month. On November 12, 2013, the Company entered into the Second Amendment to the Facilities, Support Services and Business Agreement, or the Second Amendment. The Second Amendment extended the lease and allowed year-to-year renewals.

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent events	Subsequent events: On March 3, 2016, EuroSite Power entered into a financing arrangement with a lender, pursuant to which EuroSite Power may offer to assign to the lender, and the lender may accept such assignment at its discretion, certain amounts which are payable or may become payable under selected service contracts EuroSite Power has with its customers. Under the arrangement, in exchange for the assignment of such amounts, the lender will advance to EuroSite Power a sum of monies which is determined as the aggregate of such amounts reduced by an offer specific discount rate, which varies dependent on the attendant risk. Amounts advanced are repaid as EuroSite Power’s customers make payment on amounts which become due and payable under service contracts. The Company has guaranteed payment under the arrangement. On March 24, 2016, EuroSite Power entered into a second project financing arrangement with another lender, pursuant to which EuroSite Power may offer to assign to the lender and the lender may accept such assignment at its discretion, certain amounts which are payable or may become payable under selected service contracts EuroSite Power has with its customers. Under the arrangement, in exchange for the assignment of such amounts, the lender will advance to EuroSite Power a sum of monies which is determined as the aggregate of such amounts reduced by an offer specific discount rate, which varies dependent on the attendant risk. Amounts advanced are repaid as EuroSite Power’s customers make payment on amounts which become due and payable under service contracts. In connection with any borrowings, EuroSite Power is required to grant a security interest in any and all equipment associated with the relevant service contract. On March 29, 2016, EuroSite Power entered into a Collaboration Agreement with TEDOM a.s. (or “TEDOM”). TEDOM is a Czech Republic cogeneration company that specializes in selling, manufacturing, installing and maintaining its cogeneration equipment in the European Union and other markets. The agreement provides TEDOM, its affiliates and dealers with a financial solution for customers that are not able to afford its products. In addition, it gives EuroSite the sole and exclusive right of first refusal to be the On-Site Utility provider for potential On-Site Utility customers of TEDOM, its affiliates and dealers in the EU-28 plus Turkey territories. On May 4, 2016, the Company exchanged approximately 14.72 million of its shares in EuroSite Power, or 46% of its 48% ownership in its former European subsidiary, for elimination of a portion of the outstanding 6% convertible debentures due May 2018. This partial extinguishment of debt reduced the Company's convertible debt outstanding to $8.6 million , net of the associated discount. On May 12, 2016, EuroSite Power completed a private placement with related parties of 12,608,696 shares of its common stock for aggregate proceeds of $7.25 million at $0.575 per share. The shares sold in this placement are subject to a registration rights agreement where the Company has agreed to use its best efforts to register the shares issued at the request of the holder. EuroSite used a portion of these proceeds to pay off its debt to its former Chairman, of $2,000,000 , with the balance being retained to fund operations and growth. On June 28, 2016, $2.1 million of Eurosite Power's $2.4 million of convertible debentures were converted into 3,909,260 shares of common stock of Eurosite Power at a price of $0.54 per share. Additionally, $11,000 of accrued interest was also converted at the same price. As the price used to convert the convertible debentures was less than the then contractual conversion price of $0.60 per share of common stock, the fair value of the incremental shares issued to the holders of the convertible debentures over and above the contractually required amount of $224,782 was expensed as debt conversion expense. On September 30, 2016, the Company settled $6.7 million of its $10.1 million outstanding 6% convertible debentures due May 2018 by transferring ownership of 15.2 million shares it owned of EuroSite Power in exchange for the debt. A new note evidencing the remaining balance of the debt outstanding of $3,418,681 was issued, replacing the previous note. Interest on the debt was previously prepaid through maturity and the prepayment is reflected as a discount against the debt which is amortized to interest expense over the life of the debt. On November 1, 2016, the Company's Board of Directors approved a definitive agreement whereby Tecogen Inc would acquire all of the outstanding shares of American DG in a stock-for-stock merger. Under the agreement, each share of American DG common stock will be exchanged for 0.092 shares of Tecogen common stock, valuing American DG at an approximately 27% premium to the Company's closing share price on that day. This agreement is subject to a vote of security holders of both companies. The transaction is expected to close in the first half of 2017. The Company has evaluated subsequent events through the date of this filing and determined that no other subsequent events occurred that would require recognition in the consolidated financial statements or disclosure in the notes thereto.

Summary of significant accoun22

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and include the accounts of the Company and entities in which it has a controlling financial interest. Those entities include the Company's 51.0% joint venture, American DG New York, LLC, or ADGNY, and its 48.0% owned subsidiary EuroSite Power Inc., or EuroSite Power. The interests in underlying energy system projects in ADGNY vary between the Company and its joint venture partner. As the controlling partner, all major decisions in ADGNY are made by the Company according to the joint venture agreement. Distributions, however, are made based on the economic ownership. The economic ownership is calculated by the amount invested by the Company and the noncontrolling partner in each site. Each quarter, the Company calculates a year-to-date profit/loss for each site that is part of ADGNY and the noncontrolling interest percent ownership in each site is applied to determine the noncontrolling interest share in the profit/loss. The Company follows the same calculation regarding available cash and a cash distribution is made to the noncontrolling interest partner each quarter. On the Company’s balance sheet, noncontrolling interest represents the joint venture partner’s investment in ADGNY, plus its share of after tax profits less any cash distributions. The Company owned a controlling 51.0% legal interest and had a 51.0% economic interest in ADGNY as of December 31, 2015 . As of December 31, 2015 and 2014 , the Company owned a 48.0% and a 50.1% , interest in EuroSite Power, respectively, and has consolidated EuroSite Power into its financial statements in both years in accordance with GAAP, as discussed below. The Company has consolidated the operating results and financial position of EuroSite Power as it has determined it has a controlling financial interest in EuroSite Power. This determination was based on application of the variable interest entity (VIE) model which determines whether a controlling financial interest exists by other than majority voting ownership. In applying the VIE model, the Company considered the explicit and implicit variable interests which exist in EuroSite Power including its own and its ability to direct the activities of EuroSite Power which most significantly effect it’s economic performance and the Company’s obligation to absorb the expected losses of EuroSite Power. In addition to its equity ownership in EuroSite Power, the Company has an implicit variable interest in EuroSite Power through its guarantee of the long-term convertible indebtedness of EuroSite Power. This results in the Company’s voting ownership being disproportional to its obligation to absorb the expected losses of EuroSite Power. This combined with the fact that substantially all of EuroSite Power’s activities either involve or are conducted on behalf of the Company results in EuroSite Power being considered a VIE. The Company’s level of ownership results in the Company’s ability to control the activities which most significantly effect the economic performance of EuroSite Power. This combined with the Company’s obligation to absorb losses which could be significant to EuroSite Power qualify the Company as the primary beneficiary of EuroSite Power. As the primary beneficiary of a VIE, the Company is required to consolidate the operating results and financial position of the VIE. The Company provides a guarantee with respect to the outstanding third party convertible indebtedness under EuroSite Power’s convertible debentures which it was not contractually obligated to provide. The Company also helps facilitate and assists EuroSite Power in obtaining additional sources of financing. The Company’s operations are comprised of one business segment. The Company’s business is selling energy in the form of electricity, heat, hot water and cooling to its customers under long-term sales agreements. The Company’s continuing revenue is generated in and the Company's long-lived assets are located in the United States of America. Amounts reflected in these consolidated financial statements as relating to discontinued operations were generated in or are primarily located in the United Kingdom. The Company has experienced total net losses since inception of approximately $40.6 million . For the foreseeable future, the Company expects to experience continuing operating losses and negative cash flows from operations as its management executes the current business plan. The Company believes that its existing resources, including cash and cash equivalents and future cash flow from operations, are sufficient to meet the working capital requirements of its existing business for the foreseeable future, including the next twelve months; however, as the Company continues to grow its business by adding more energy systems, the cash requirements will increase. Beyond December 2, 2017 , the Company may need to raise additional capital through a debt financing or an equity offering to meet its operating and capital needs. There can be no assurance, however, that the Company will be successful in its fundraising efforts or that additional funds will be available on acceptable terms, if at all. If the Company is unable to raise additional capital in 2017 it may need to terminate certain of its employees and adjust its current business plan. Financial considerations may cause the Company to modify planned deployment of new energy systems and may decide to suspend installations until it is able to secure additional working capital. The Company will evaluate possible acquisitions of, or investments in, businesses, technologies and products that are complementary to its business; however, the Company is not currently engaged in such discussions.
Use of Estimates	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Revenue Recognition	Revenue from energy contracts is recognized when electricity, heat, and chilled water is produced by the cogeneration systems on-site. The Company bills each month based on various meter readings installed at each site. The amount of energy produced by on-site energy systems is invoiced, as determined by a contractually defined formula. Under certain energy contracts, the customer directly acquires the fuel to power the systems and receives credit for that expense from the Company. The credit is recorded as a cost of sale. Revenues from operations, including shared savings are recorded when provided and verified. Maintenance service revenue is recognized over the term of the agreement and is billed on a monthly basis in arrears. As a byproduct of the energy business, in some cases, the customer may choose to own the energy system rather than have it owned by American DG Energy. In this case, the Company accounts for revenue, or turnkey revenue, and costs using the percentage-of-completion method of accounting. Under the percentage-of-completion method of accounting, revenues are recognized by applying percentages of completion to the total estimated revenues for the respective contracts. Costs are recognized as incurred. The percentages of completion are determined by relating the actual cost of work performed to date to the current estimated total cost at completion of the respective contracts. When the estimate on a contract indicates a loss, the Company records the entire expected loss, regardless of the percentage of completion. The excess of contract costs and profit recognized to date on the percentage-of-completion accounting method in excess of billings is recorded as unbilled revenue. Billings in excess of related costs and estimated earnings is recorded as deferred revenue. Customers may buy out their long-term obligation under energy contracts and purchase the underlying equipment from the Company. Any resulting gain on these transactions is recognized over the payment period in the accompanying consolidated statements of operations. The Company is able to participate in certain energy related programs and receive payments due to the availability of its energy systems. These programs provide incentive payments for either the reduction of electricity usage or the increase in electricity production during periods of peak usage throughout a utility territory.
Cash and Cash Equivalents	The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. The Company has cash balances in certain financial institutions in amounts which occasionally exceed current federal deposit insurance limits. The financial stability of these institutions is continually reviewed by senior management. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents.
Concentrations and Credit Risk	Financial instruments, which potentially subject the Company to concentrations of credit risk, consist of highly liquid cash equivalents and trade receivables. The Company’s cash equivalents are placed with certain financial institutions and issuers.
Accounts Receivable	The Company maintains receivable balances primarily with customers located throughout New York, New Jersey and the United Kingdom. The Company reviews its customers’ credit history before extending credit and generally does not require collateral. An allowance for doubtful accounts is established based upon factors surrounding the credit risk of specific customers, historical trends and other information. Generally, such losses have been within management’s expectations. Bad debt is written off against the allowance for doubtful accounts when identified
Inventory	Inventories, which consisted of finished goods, are stated at the lower of cost or market, valued on a first-in, first-out basis. Inventory is reviewed periodically for slow-moving and obsolete items.
Supply Concentrations	Most of the Company’s cogeneration unit purchases for the years ended December 31, 2015 and 2014 were from one vendor (see “Note 10 - Related parties”). The Company believes there are sufficient alternative vendors available to ensure a constant supply of cogeneration units on comparable terms. However, in the event of a change in suppliers, there could be a delay in obtaining units which could result in a temporary slowdown of installing additional income producing sites. In addition, the majority of the Company’s units are installed and maintained by the noncontrolling interest holder or maintained by Tecogen Inc., or Tecogen (see Note 10 - Related parties). The Company believes there are sufficient alternative vendors available to ensure a constant supply of maintenance and installation services on comparable terms. However, in the event of a change of vendor, there could be a delay in installation or maintenance services.
Property, Plant and Equipment	Property, plant and equipment are stated at cost. Depreciation and amortization are computed using the straight-line method at rates sufficient to write off the cost of the applicable assets over their estimated useful lives. Repairs and maintenance are expensed as incurred. The Company reviews its energy systems for potential impairment whenever events or changes in business circumstances indicate that the carrying value of the assets may not be fully recoverable or that the useful lives of the assets are no longer appropriate. The Company evaluates the recoverability of its long-lived assets when potential impairment is indicated by comparing the remaining net book value of the assets to the estimated future undiscounted cash flows attributable to such assets. The useful life of the Company’s energy systems is the lesser of the economic life of the asset or the term of the underlying contract with the customer, typically 12 to 15 years. If impairment is indicated, the asset is written down to its estimated fair value based on a discounted cash flow analysis. During the years ended December 31, 2015 and 2014 , the Company recorded asset impairment losses totaling $618,661 and $526,766 , respectively, relating to certain of its energy systems as a result of changing or unexpected conditions with respect to the energy systems which impact the estimated future cash flows. The conditional changes impacting the estimated future cash flows related to these assets resulted from changes in the level of demand for electricity and/or hot water at particular installations, finalization of start-up period customization at particular installations and/or price changes in electrical and natural gas rates, all of which impacted estimated future cash flows. The Company receives rebates and incentives from various utility companies and governmental agencies which are accounted for as a reduction in the book value of the assets. The rebates are payable from the utility to the Company and are applied against the cost of construction, therefore reducing the book value of the installation. As a reduction of the facility construction costs, these rebates are treated as an investing activity in the statements of cash flows. The rebates received by the Company from the utilities that apply to the cost of construction are one time rebates based on the installed cost, capacity and thermal efficiency of the installed unit and are earned upon the installation and inspection by the utility and are not related to or subject to adjustment based on the future operating performance of the installed units. The rebate agreements with utilities are based on standard terms and conditions, the most significant being customer eligibility and post-installation work verification by a specific date.
Stock-Based Compensation	Stock based compensation cost is measured at the grant date based on the estimated fair value of the award and is recognized as an expense in the consolidated statements of operations over the requisite service period. The fair value of stock options granted is estimated using the Black-Scholes option pricing valuation model. The Company recognizes compensation on a straight-line basis over the expected life for each separately vesting portion of the option award. Use of a valuation model requires management to make certain assumptions with respect to selected model inputs. Expected volatility is calculated based on the Company’s historic volatility over the expected life of the option grant. The average expected life is estimated using the simplified method for “plain vanilla” options. The simplified method determines the expected life in years based on the vesting period and contractual terms as set forth when the award is made. The Company uses the simplified method for awards of stock-based compensation since it does not have the necessary historical exercise and forfeiture data to determine an expected life for stock options. The risk-free interest rate is based on U.S. Treasury zero-coupon issues with a remaining term which approximates the expected life assumed at the date of grant. When options are exercised the Company normally issues new shares.
Loss per Common Share	The Company computes basic loss per share by dividing net income (loss) for the period by the weighted average number of shares of common stock outstanding during the period. The Company computes diluted earnings per common share using the treasury stock method. For purposes of calculating diluted earnings per share, the Company considers its shares issuable in connection with convertible debentures, stock options and warrants to be dilutive common stock equivalents when the exercise price is less than the average market price of its common stock for the period. For the year ended December 31, 2015 , the Company excluded 14,336,083 anti-dilutive shares resulting from exercise of stock options, warrants and shares issuable in connection with convertible debentures, and for the year ended December 31, 2014 , the Company excluded 15,763,083 anti-dilutive shares resulting from exercise of stock options, warrants and unvested restricted stock. All shares issuable for both years were anti-dilutive because of the reported net loss.
Income Taxes	As part of the process of preparing its consolidated financial statements, the Company is required to estimate its income taxes in each of the jurisdictions in which it operates. This process involves the Company estimating its actual current tax exposure together with assessing temporary differences resulting from differing treatment of items, such as depreciation and certain accrued liabilities for tax and accounting purposes. These differences result in deferred tax assets and liabilities, which are included within the Company’s consolidated balance sheet. The Company must then assess the likelihood that its deferred tax assets will be recovered from future taxable income and to the extent it believes that recovery is not likely, the Company must establish a valuation allowance. The Company is allowed to recognize the tax benefits of uncertain tax positions only where the position is “more likely than not” to be sustained assuming examination by tax authorities. The amount recognized is the amount that represents the largest amount of tax benefit that is greater than 50.0% likely of being ultimately realized. A liability is recognized for any benefit claimed, or expected to be claimed, in a tax return in excess of the benefit recorded in the financial statements, along with any interest and penalties (if applicable) on that excess. The tax years 2011 through 2014 remain open to examination by major taxing jurisdictions to which the Company is subject, which are primarily in the United States, as carry forward attributes generated in years past may still be adjusted upon examination by the Internal Revenue Service or state tax authorities if they are or will be used in a future period. The Company is currently not under examination by the Internal Revenue Service or any other jurisdiction for any tax years. The Company did not recognize any interest and penalties associated with unrecognized tax benefits in the accompanying consolidated financial statements. The Company would record any such interest and penalties as a component of interest expense. The Company does not expect any material changes to the unrecognized benefits within twelve months of the reporting date.
Fair Value of Financial Instruments	The Company’s financial instruments are cash and cash equivalents, short-term investments, accounts receivable, investment securities, accounts payable, convertible debentures and amounts due to/from related parties. The recorded values of cash and cash equivalents, accounts receivable, accounts payable and amounts due to/from related parties approximate their fair values based on their short-term nature. The investment securities and warrant liability are recorded at fair value. The carrying value of the convertible debentures and note payable related party on the balance sheet at December 31, 2015 approximates fair value as the terms approximate those currently available for similar instruments.
Impact of New Accounting Pronouncements	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP and the International Financial Reporting Standards. This guidance supersedes previously issued guidance on revenue recognition and gives a five step process an entity should follow so that the entity recognizes revenue that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This new guidance will be effective for our fiscal 2018 reporting period and must be applied either retrospectively during each prior reporting period presented or retrospectively with the cumulative effect of initially applying this guidance recognized at the date of the initial application. Early adoption is not permitted. We are currently evaluating the impact of the adoption of this ASU on our consolidated financial statements. In August 2014, the FASB issued ASU 2014-15 "Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern". The new standard provides guidance around management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. Early adoption is permitted. The adoption of this ASU is not expected to have a material impact on our consolidated financial statement. In November 2015, the FASB issued ASU 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes" to simplify the presentation of deferred income taxes. Under current GAAP, an entity is required to separate deferred income tax liabilities and assets into current and noncurrent amounts in a classified statement of financial position. The new standard requires deferred tax liabilities and assets to be classified as noncurrent in a classified statement of financial position. The current requirement that deferred tax liabilities and assets of a tax-paying component of an entity be offset and presented as a single amount is not affected by the amendments. The new standard will align the presentation of deferred income tax and liabilities with the International Financial Reporting Standards (IFRS), which requires deferred tax assets and liabilities to be classified as noncurrent in a classified statement of financial position. The amendments take effect for financial statements issued for annual periods beginning after December 15, 2016, and interim periods within those annual periods.

The Company The Company (Tables

The Company The Company (Tables)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Discontinued Operations	Following is a reconciliation of the major line items comprising loss from discontinued operations for the years ended December 31, 2015 and 2014 : December 31, 2015 December 31, 2014 Revenue $ 2,198,721 $ 1,577,873 Cost of sales $ 2,314,525 $ 1,799,284 Operating expenses $ 1,611,786 $ 1,480,629 Other expenses, net $ 36,708 $ 1,255,738 Pretax loss from discontinued operations $ 1,764,298 $ 2,594,022 Income tax benefit $ 380,176 $ 648,917 Loss from discontinued operations $ 1,384,122 $ 1,945,105 Loss from discontinued operations attributable to noncontrolling interest $ 679,149 $ 745,809 Loss from discontinued operations attributable to American DG Energy Inc. $ 704,973 $ 1,199,296 The total operating and investing cash flows of the discontinued operation for the years ended December 31, 2015 and 2014 are as follows: December 31, 2015 December 31, 2014 Net cash used in operating activities $ (365,186 ) $ (796,024 ) Net cash used in investing activities $ (1,823,847 ) $ (2,843,053 )

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment consist of the following as of December 31, 2015 and 2014 , respectively: 2015 2014 Energy systems $ 23,348,928 $ 25,521,585 Computer equipment and software 143,204 121,958 Furniture and fixtures 85,463 87,051 Vehicles 194,192 226,018 23,771,787 25,956,612 Less — accumulated depreciation (8,822,809 ) (9,124,309 ) 14,948,978 16,832,303 Construction in progress 3,001,809 1,703,947 $ 17,950,787 $ 18,536,250

Accrued expenses and other cu25

Accrued expenses and other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	As of December 31, 2015 and 2014 , accrued expenses and other current liabilities consisted of: 2015 2014 Professional fees accrual $ 147,321 $ 131,078 Payroll accrual 65,101 164,700 Customer deposits 36,525 41,907 Accrued taxes 6,635 4,025 Deferred revenue 2,228 13,608 Total Accrued expenses and other current liabilities $ 257,810 $ 355,318

Convertible debentures (Tables)

Convertible debentures (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Fair Value Measurements Assumptions	The following table provides quantitative information used in the fair value measurement, including the assumptions for the significant unobservable inputs used in the binomial lattice model valuation: Notional amount $ 4,000,000 Par amount $ 1,000 Interest rate 4.0 Conversion ratio 1,667 Conversion price, per share $ 0.60 Stock price as of the valuation date $ 0.51 Historical realized weekly volatility 87 % Risk free rate 0.9 % Discrete dividend payment rate — %
Convertible Debt	The face amount of convertible debentures and the related premium or discount are as follows as of December 31, 2015 and 2014, respectively: 2015 American DG Energy EuroSite Power Total Face amount $ 19,400,000 $ 2,400,000 $ 21,800,000 Premium (discount) (3,321,088 ) 136,422 (3,184,666 ) 16,078,912 2,536,422 18,615,334 Less amounts due to related parties (16,078,912 ) (951,158 ) (17,030,070 ) $ — $ 1,585,264 $ 1,585,264 2014 American DG Energy EuroSite Power Total Face amount $ 19,400,000 $ 2,400,000 $ 21,800,000 Premium (discount) (4,523,051 ) 232,710 (4,290,341 ) 14,876,949 2,632,710 17,509,659 Less amounts due to related parties (14,876,949 ) (987,266 ) (15,864,215 ) $ — $ 1,645,444 $ 1,645,444

Stockholders' equity (Tables)

Stockholders' equity (Tables)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule Of Warrants Activity	Warrant activity for the years ended December 31, 2015 and 2014 was as follows: Number of Warrants Weighted Average Exercise Price Balance, December 31, 2013 507,500 $ 3.24 Granted 2,942,270 1.89 Exercised — — Expired — — Balance, December 31, 2014 3,449,770 $ 2.09 Granted — — Exercised — — Expired (500,000 ) 3.25 Balance, December 31, 2015 2,949,770 $ 1.89
Summary of Fair Value Stock Option Assumptions	The weighted average assumptions used in the Black-Scholes option pricing model are as follows: 2015 2014 Stock options and restricted stock awards Expected life 6.25 years 6.25 years Risk-free interest rate 2.09 % 2.03 % Expected volatility 72.90 % 68.80 %
American DG Energy
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Stock Options, Activity	Stock option activity for the year ended December 31, 2015 was as follows: Common Stock Options Number of Options Weighted Average Exercise Price Weighted Average Remaining Life Aggregate Intrinsic Value Outstanding, December 31, 2014 3,119,000 $1.32 5.15 years $ 25,600 Granted 200,000 $0.41 Exercised — — Canceled (535,000 ) $1.42 Expired (306,000 ) $2.59 Outstanding, December 31, 2015 2,478,000 $1.06 4.93 years $ 4,000 Exercisable, December 31, 2015 1,308,000 $1.22 $ — Vested and expected to vest, December 31, 2015 2,478,000 $1.06 $ 4,000
Schedule of Changes in the Company's Ownership Interest in its Subsidiary	The following schedule discloses the effects of changes in the Company's ownership interest in its consolidated subsidiaries and former consolidated subsidiaries on the Company's equity for the years ended December 31, 2015 and 2014 . 2015 2014 Loss attributable to American DG Energy Inc. $ (5,430,403 ) $ (5,888,894 ) Transfers (to) from noncontrolling interest: Decrease in additional paid-in capital for exchange of 1,320,000 EuroSite Power common shares for current and future interest related to the Company's convertible debentures (see "Note 6 - Convertible debentures") (15,250 ) Reorganization of subsidiary ownership (See "Note 7 - Stockholders' equity") (732,116 ) Increase in additional paid-in capital for exchange of 9,409,000 EuroSite Power common shares for current and future interest related to the Company's convertible debentures (see "Note 6 - Convertible debentures") 4,704,500 Increase in additional paid-in-capital for sale by EuroSite Power of 3,000,000 common shares and warrants 1,486,329 Decrease in additional paid-in-capital for reacquisition by EuroSite Power of 100,000 of its common shares (42,902 ) Increase in additional paid-in-capital for conversion of EuroSite Power convertible debentures into 6,100,000 common shares of EuroSite Power 2,455,377 Noncontrolling interest share of transactions affecting subsidiary ownership 426,980 (2,718,159 ) Subtotal transfers (to) from noncontrolling interest (320,386 ) 5,885,145 Change from net loss attributable to American DG Energy Inc. and transfers (to) from noncontrolling interest $ (5,750,789 ) $ (3,749 )
EuroSite Power
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Stock Options, Activity	Stock option activity for the year ended December 31, 2015 was as follows: Common Stock Options Number of Options Weighted Average Exercise Price Weighted Average Remaining Life Aggregate Intrinsic Value Outstanding, December 31, 2014 4,305,000 $0.87 6.84 years $ 9,800 Granted 400,000 $0.70 Exercised — — Canceled (595,000 ) $0.88 Expired — — Outstanding, December 31, 2015 4,110,000 $0.84 6.06 years $ 410,500 Exercisable, December 31, 2015 3,442,500 $0.89 $ 208,125 Vested and expected to vest, December 31, 2015 4,110,000 $0.84 $ 410,500

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule Of Warrant Liabilities	The following table summarizes the warrant activity for the period: Warrant Liabilities Fair value at December 31, 2014 $ 6,780 Fair value adjustment at December 14, 2015 (6,780 ) Fair value at December 31, 2015 $ —

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Components of Loss from Operations	The components of loss from operations for both continuing and discontinued operations before income taxes for the years ended December 31, 2015 and 2014 are as follows: 2015 2014 Domestic $ (4,731,000 ) $ (5,310,000 ) Foreign (1,304,000 ) (1,224,000 ) $ (6,035,000 ) $ (6,534,000 )
Reconciliation of Federal Statutory Income Tax Provision to Company's Actual Provision	econciliation of federal statutory income tax provision to the Company’s actual provision for the years ended December 31, 2015 and 2014 , respectively, are as follows, including a provision of $27,605 and $3,877 for American DG and a benefit of $380,176 and $648,917 for EuroSite Power: 2015 2014 Benefit at federal statutory tax rate $ (2,052,000 ) $ (2,222,000 ) Foreign rate differential 209,000 159,000 UK Energy Incentives (380,000 ) (649,000 ) Unbenefited operating losses 1,843,000 2,063,000 Provision for income taxes 37,000 4,000 Income tax provision $ (343,000 ) $ (645,000 )
Schedule of Deferred Tax Assets	The component of net deferred tax assets recognized in the accompanying balance sheets at December 31, 2015 and 2014 , respectively, are as follows: 2015 2014 Net operating loss carryforwards $ 11,875,000 $ 10,838,000 Accrued expenses and other 57,000 100,000 Stock compensation 1,312,000 1,194,000 Depreciation 357,000 (216,000 ) 13,601,000 11,916,000 Valuation allowance (13,601,000 ) (11,916,000 ) Net deferred tax asset $ — $ —

The Company (Details)

The Company (Details)	12 Months Ended
	Dec. 31, 2015energy_system
Schedule of Energy Operations [Line Items]
Number Of Energy Systems Installed	92
Minimum
Schedule of Energy Operations [Line Items]
Length of long-term energy sales agreements	10
Maximum
Schedule of Energy Operations [Line Items]
Length of long-term energy sales agreements	15

The Company (Discontinued Opera

The Company (Discontinued Operations) (Details) - USD ($)	Sep. 30, 2016	May 04, 2016	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue				$ 2,198,721	$ 1,577,873
Cost of sales				2,314,525	1,799,284
Operating expenses				1,611,786	1,480,629
Other expenses, net				36,708	1,255,738
Pretax loss from discontinued operations				1,764,298	2,594,022
Income tax benefit				380,176	648,917
Loss from discontinued operations				1,384,122	1,945,105
Loss from discontinued operations attributable to noncontrolling interest				679,149	745,809
Loss from discontinued operations attributable to American DG Energy Inc.				704,973	1,199,296
Net cash used in operating activities				(365,186)	(796,024)
Net cash used in investing activities				$ (1,823,847)	$ (2,843,053)
Subsequent Event | 6% Convertible Debentures
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount of debt converted to equity		$ 8,600,000
Interest rate on convertible debt (percent)	6.00%	6.00%
Subsequent Event | Subsidiaries | 6% Convertible Debentures
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount of debt converted to equity	$ 6,700,000		$ 16,000,000
Convertible debt	$ 10,100,000	$ 19,400,000	$ 10,100,000
Interest rate on convertible debt (percent)	6.00%
Subsequent Event | EuroSite Power
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage of equity method investment (percent)						48.04%
Ownership by affiliated party (percent)	2.03%		2.03%

Summary of significant accoun32

Summary of significant accounting policies (Details) - segment	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Subsidary or Equity Method Investee [Line Items]
Number of Operating Segments	1
Eurosite Power Inc
Subsidary or Equity Method Investee [Line Items]
Percentage of ownership In subsidiary	48.00%	50.10%
American DG New York, LLC
Subsidary or Equity Method Investee [Line Items]
Percentage Of Ownership In Joint Venture	51.00%
Percentage Of Economic Interest	51.00%

Summary of significant accoun33

Summary of significant accounting policies (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Net losses since inception	$ (40,622,774)	$ (35,232,411)
Revenue recognized from demand response activity	137,896	247,518
Cash and Cash Equivalents concentration risk	$ 3,981,044
Maximum maturity period for highly liquid investments	3 months
Inventory reserve	$ 9,750	$ 0
Antidilutive shares excluded from computation of loss per share (shares)	14,336,083	15,763,083

Summary of significant accoun34

Summary of significant accounting policies (Accounts Receivable and Payable) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)customer	Dec. 31, 2014USD ($)customer
Concentration Risk [Line Items]
Allowance for Doubtful Accounts Receivable | $	$ 155,000	$ 112,000
Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Number Of Major Customers		4
Percentage of concentration	45.60%	31.10%
Customer Concentration Risk | Sales
Concentration Risk [Line Items]
Number Of Major Customers	1	1
Percentage of concentration	18.00%	13.00%

Summary of significant accoun35

Summary of significant accounting policies (Accounts Payable and Supply Concentrations) (Details) - vendor	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Supplier Concentration Risk
Concentration Risk [Line Items]
Number of Major Vendors	1	1

Summary of significant accoun36

Summary of significant accounting policies (Property and Equipment) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Non-cash site impairments	$ 618,661	$ 526,766
Rebates applied to cost of construction	$ 32,198	$ 27,500
Minimum | Energy Systems
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	12 years
Maximum | Energy Systems
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	15 years

Property, plant and equipment37

Property, plant and equipment (Summary of Property, Plant and Equipment) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 23,771,787	$ 25,956,612
Less ----- accumulated depreciation	(8,822,809)	(9,124,309)
Property, plant and equipment, before contruction in progress	14,948,978	16,832,303
Construction in progress	3,001,809	1,703,947
Property, plant and equipment, net	17,950,787	18,536,250
Energy Systems
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	23,348,928	25,521,585
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	143,204	121,958
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	85,463	87,051
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 194,192	$ 226,018

Property, plant and equipment38

Property, plant and equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,776,048	$ 1,560,296

ADGNY Reorganization (Details)

ADGNY Reorganization (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Jan. 29, 2015
Investments in and Advances to Affiliates [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				5.00%
Impact of exchange resulting from ADGNY reorganization		$ (732,016)
Gain attributable to distribution of nonmonetary assets to noncontrolling interest		157,870	$ 0
American DG New York, LLC
Investments in and Advances to Affiliates [Line Items]
Payment to acquire additional noncontrolling interest	$ 100,000
Shares issued to acquire additional noncontrolling interest (shares)	100,000
Noncontrolling Interest, Ownership Percentage by Parent	51.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Legal Interest	51.00%
Gain attributable to distribution of nonmonetary assets to noncontrolling interest		157,870
Additional Paid-in Capital
Investments in and Advances to Affiliates [Line Items]
Impact of exchange resulting from ADGNY reorganization		$ (732,116)

Accrued expenses and other cu40

Accrued expenses and other current liabilities (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Professional fees accrual	$ 147,321	$ 131,078
Payroll accrual	65,101	164,700
Customer deposits	36,525	41,907
Accrued taxes	6,635	4,025
Deferred revenue	2,228	13,608
Total Accrued expenses and other current liabilities	$ 257,810	$ 355,318

Convertible debentures (Details

Convertible debentures (Details) - USD ($)	Oct. 03, 2014	May 25, 2014	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Interest		$ 582,000
Common stock, shares issued		260,154	50,684,095	52,140,001
Common stock, par value (usd per share)		$ 2.24	$ 0.001	$ 0.001
Reduction in non-cash interest expense adjusted for the difference between the average stock price and the fair market value		$ 42,368
Interest on convertible debentures paid in stock of subsidiary			$ 0	$ 585,718
Impact of exchange resulting from ADGNY reorganization			0	4,207,411
Class of Warrant or Right, Term	3 years
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.60
Fair value of warrant exchanged for future convertible debenture interest	$ 84,911		$ 0	84,911
Convertible Debentures 2010
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage To Fully Accrete To Face Value			7.80%
Convertible Debt
Debt Instrument [Line Items]
Face amount			$ 21,800,000	21,800,000
Debt Instrument, Unamortized Discount			3,321,088	4,523,051
Amortization of convertible debt premium			$ 1,191,333	162,486
Convertible Debt | Convertible Debentures 2010
Debt Instrument [Line Items]
Interest rate			6.00%
American DG Energy | Convertible Debt
Debt Instrument [Line Items]
Face amount			$ 19,400,000	19,400,000
Interest rate			6.00%
Debt Instrument, Convertible, Conversion Price (in dollars per share)			$ 2.11
Percentage Of Option To Redeem Par Value			115.00%
EuroSite Power
Debt Instrument [Line Items]
Paid-in-Kind Interest, Shares	1,164,000
Interest on convertible debentures paid in stock of subsidiary	$ 582,000
Paid-in-Kind Interest, Shares, Prepayment	8,245,000
Impact of exchange resulting from ADGNY reorganization	$ 4,122,500
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	1,164,000
EuroSite Power | Convertible Debt
Debt Instrument [Line Items]
Face amount			$ 2,400,000	2,400,000
Debt Instrument, Convertible, Conversion Price (in dollars per share)			$ 0.50
Noncontrolling Interest
Debt Instrument [Line Items]
Impact of exchange resulting from ADGNY reorganization				$ 0

Convertible debentures (Eurosit

Convertible debentures (Eurosite Power Convertible Debenture) (Details)	Oct. 03, 2014USD ($)	Apr. 15, 2014USD ($)$ / shares	Jun. 14, 2013USD ($)shares	Feb. 26, 2013USD ($)	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)	Feb. 20, 2014USD ($)shares
Debt Instrument [Line Items]
Loss on extinguishment of debt					$ (704,973)	$ (1,199,296)
Debt Instrument, Unamortized Premium					136,422
Induced Conversion of Convertible Debt Expense						324,977
Amortization					96,288
Convertible Debt
Debt Instrument [Line Items]
Face amount					21,800,000	21,800,000
Convertible Debt | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Face amount					$ 1,000
Interest rate					400.00%
Loss on extinguishment of debt					$ (713,577)
Extinguishment of Debt, Amount					180,400
Long-term Debt, Gross					4,000,000
Debt Instrument, Unamortized Premium					$ 180,400
Debt Instrument, Convertible, Conversion Price | $ / shares					$ 0.60
Debt Instrument, Convertible, Conversion Ratio					1,667
Company stock price | $ / shares					$ 0.51
Volatility					87.00%
Risk -free rate					0.90%
Discrete dividend payment rate					0.00%
Convertible Debt | Note 1 300K Senior Convertible Note Due 2018
Debt Instrument [Line Items]
Face amount		$ 1,450,000
Interest rate		4.00%
Debt Instrument, Term		4 years
Debt Instrument, Convertible, Conversion Price | $ / shares		$ 0.60
EuroSite Power
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,100,000
Registration Rights Percentage			30.00%
Registration Rights, Offering Price, Net			$ 250,000
EuroSite Power | Senior Unsecured Convertible Notes Due 2015
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 1,100,000
Interest rate			6.00%
EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 1,100,000
EuroSite Power | Unsecured Debt | Senior Unsecured Convertible Notes Due 2015
Debt Instrument [Line Items]
Face amount			$ 4,000,000
Interest rate			4.00%
Debt Instrument, Convertible, Shares | shares			1,000
Debt Instrument, Convertible, Conversion Rate Denominator			$ 1,000
Debt Instrument, Extension Period			3 years
Debt Instrument, Interest Rate, Increase (Decrease)			(3.00%)
Debt Instrument, Term			3 years
EuroSite Power | Convertible Debt
Debt Instrument [Line Items]
Face amount					$ 2,400,000	$ 2,400,000
Extinguishment of Debt, Amount	$ 3,050,000
Debt Instrument, Convertible, Conversion Price | $ / shares					$ 0.50
Convertible debt					$ 3,050,000
Conversion of Stock, Shares Issued | shares					6,100,000
EuroSite Power | Convertible Debt | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Interest rate							4.00%
Debt Instrument, Convertible, Shares | shares							1,667
Debt Instrument, Convertible, Conversion Rate Denominator							$ 1,000
Long-term Debt, Fair Value					$ 4,656,000
Long-term Debt, Gross					4,000,000		4,000,000
Debt Instrument, Unamortized Premium					$ 656,000
Prepayment from Related Party for Future Purchases | EuroSite Power
Debt Instrument [Line Items]
Related party transaction, discount rate				6.00%
Bruno Meier | EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							250,000
Joan Giacinti | EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							300,000
Charles T. Maxwell | EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							250,000
Nettlestone Enterprises Limited | EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							300,000
Perastra Management Management S.A | EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							1,500,000
Yves Micheli | EuroSite Power | Senior Convertible Notes Due 2017
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 300,000

Convertible debentures (Summary

Convertible debentures (Summary of Debt) (Details) - Convertible Debt - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Face amount	$ 21,800,000	$ 21,800,000
Premium (discount)	3,184,666	4,290,341
Convertible Debt, Noncurrent, Excluding Amount Due To Related Party	18,615,334	17,509,659
Less amounts due to related parties	(17,030,070)	(15,864,215)
Convertible Debt, Noncurrent, Including Amount Due To Related Party	1,585,264	1,645,444
American DG Energy
Debt Instrument [Line Items]
Face amount	19,400,000	19,400,000
Premium (discount)	3,321,088	4,523,051
Convertible Debt, Noncurrent, Excluding Amount Due To Related Party	16,078,912	14,876,949
Less amounts due to related parties	(16,078,912)	(14,876,949)
Convertible Debt, Noncurrent, Including Amount Due To Related Party	0	0
EuroSite Power
Debt Instrument [Line Items]
Face amount	2,400,000	2,400,000
Premium (discount)	(136,422)	(232,710)
Convertible Debt, Noncurrent, Excluding Amount Due To Related Party	2,536,422	2,632,710
Less amounts due to related parties	(951,158)	(987,266)
Convertible Debt, Noncurrent, Including Amount Due To Related Party	$ 1,585,264	$ 1,645,444

Stockholders' equity (Details)

Stockholders' equity (Details) - USD ($)

Jan. 29, 2015

Sep. 19, 2014

Aug. 06, 2014

Dec. 09, 2010

Jun. 30, 2015

Dec. 31, 2015

Dec. 31, 2014

Jul. 07, 2015

Dec. 30, 2014

Oct. 03, 2014

Dec. 31, 2013

Jun. 13, 2011

Class of Stock [Line Items]

Warrants Expiration Term

5 years

Class of Warrant or Right, Exercise Price of Warrants or Rights

$ 0.60

Proceeds from Issuance of Common Stock

$ 0

$ 3,266,275

Stock repurchase program, number of shares authorized to be repurchased (shares)

1,000,000

Stock repurchase program, authorized amount

$ 1,100,000

Stock repurchase program, period in force

24 months

Share repurchase program, maximum authorized purchase price per share (usd per share)

$ 1.30

Share repurchase program (shares)

235,906

588,073

Stock repurchased during period, average price per share (usd per share)

$ 0.55

$ 0.80

Ownership percentage by IN Holdings, Inc. (percent, less than)

5.00%

Fair value of common stock issued in conjunction with exchange of EuroSite common stock

$ 0

Common stock, shares outstanding

50,684,095

52,140,001

Expected life

6 years 3 months

6 years 3 months

Share-based Compensation

$ 222,130

$ 310,900

Fair Value Assumptions Risk Free Interest Rate

2.09%

2.03%

Expected volatility

72.90%

68.80%

American DG Energy

Class of Stock [Line Items]

Number of Shares Authorized

8,000,000

Allocated Share-based Compensation Expense

$ 222,128

$ 310,900

Total Compensation Cost Not yet Recognized

$ 212,575

$ 696,870

Nonvested Awards, Weighted Average Period That Total Compensation Costs Will Be Recognized

2 years 6 months

Number of Non-qualified Options Issued in Period

1,049,000

Nonqualified option, exercise price per share Granted Lower Range (usd per share)

$ 0.29

$ 0.52

Nonqualified option, exercise price per share Granted Upper Range (usd per share)

$ 0.52

$ 2.18

Options Issued, Fair Value

$ 53,195

$ 678,570

Options Granted in Period, Weighted Average Grant Date Fair Value

$ 0.27

$ 0.63

Number of Options Granted (in shares)

200,000

Weighted Average Exercise Price Granted (usd per share)

$ 0.41

Number of Options Outstanding (in shares)

2,478,000

3,119,000

American DG Energy | Stock Options

Class of Stock [Line Items]

Options, expiration period

10 years

American DG Energy | Minimum

Class of Stock [Line Items]

Vesting Period

4 years

American DG Energy | Minimum | Stock Options

Class of Stock [Line Items]

Vesting Period

4 years

American DG Energy | Maximum

Class of Stock [Line Items]

Vesting Period

10 years

EuroSite Power

Class of Stock [Line Items]

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

1,164,000

Vesting Period

4 years

Nonvested Awards, Weighted Average Period That Total Compensation Costs Will Be Recognized

2 years 11 months 9 days

Capital Shares Reserved for Future Issuance

390,000

Share-based Compensation

$ 77,059

Number of Options Granted (in shares)

400,000

Number of Options Outstanding (in shares)

4,110,000

4,305,000

Total Compensation Cost Not yet Recognized, Stock Options

$ 90,202

EuroSite Power | Stock Compensation Plan

Class of Stock [Line Items]

Number of Shares Authorized

4,500,000

EuroSite Power | Stock Options

Class of Stock [Line Items]

Vesting Period

4 years

4 years

Options, expiration period

10 years

10 years

Option exercise price, lower range (usd per share)

$ 0.40

Option exercise price, upper range (usd per share)

$ 0.89

Expected life

6 years 3 months

6 years 3 months

Options Granted in Period, Weighted Average Grant Date Fair Value

$ 0.24

$ 0.25

Option grants in period

400,000

520,000

Fair value of option grants

$ 96,220

$ 129,083

Weighted Average Exercise Price Granted (usd per share)

$ 0.70

$ 0.65

Fair Value Assumptions Risk Free Interest Rate

2.10%

2.10%

Expected volatility

31.08%

34.40%

American DG New York, LLC

Class of Stock [Line Items]

Ownership percentage by IN Holdings, Inc. (percent, less than)

49.00%

Shares issued to acquire additional noncontrolling interest (shares)

100,000

Stock Issued During Period, Value, Purchase of Assets, Fair Value

$ 63,000

Director | American DG Energy

Class of Stock [Line Items]

Number of Non-qualified Options Issued in Period

20,000

Employee | EuroSite Power | Stock Options

Class of Stock [Line Items]

Option grants in period

25,000

Director

Class of Stock [Line Items]

Interest rate

6.00%

Note payable, related party

$ 1,000,000

Executive Officer | EuroSite Power | Stock Options

Class of Stock [Line Items]

Option grants in period

375,000

Common Stock

Class of Stock [Line Items]

Stock Issued During Period, Shares, New Issues

2,650,000

Share repurchase program (shares)

235,906

588,073

Stock Repurchased and Retired During Period, Shares

(1,320,000)

Fair value of common stock issued in conjunction with exchange of EuroSite common stock

$ (1,320)

Common stock, shares outstanding

50,684,095

52,140,001

49,817,920

Noncontrolling Interest

Class of Stock [Line Items]

Fair value of common stock issued in conjunction with exchange of EuroSite common stock

$ 0

Three And Five Year Warrants

Class of Stock [Line Items]

Proceeds from Issuance of Common Stock

$ 3,269,275

Three Year Warrants

Class of Stock [Line Items]

Warrants Expiration Term

3 years

Class of Warrant or Right, Number of Securities Called by Warrants or Rights

2,829,732

Five Year Warrants

Class of Stock [Line Items]

Warrants Expiration Term

5 years

Class of Warrant or Right, Outstanding

112,538

Class of Warrant or Right, Exercise Price of Warrants or Rights

$ 1.89

Expire in Ten Years | American DG Energy | Stock Options

Class of Stock [Line Items]

Number of Non-qualified Options Issued in Period

280,000

Options, expiration period

10 years

Expire in Five Years | American DG Energy | Stock Options

Class of Stock [Line Items]

Number of Non-qualified Options Issued in Period

150,000

Options, expiration period

5 years

Grant One | Executive Officer | EuroSite Power | Stock Options

Class of Stock [Line Items]

Expected life

6 years 3 months

Option grants in period

220,000

Fair value of option grants

$ 75,358

Weighted Average Exercise Price Granted (usd per share)

$ 0.89

Fair Value Assumptions Risk Free Interest Rate

2.18%

Expected volatility

35.10%

Grant Two | Executive Officer | EuroSite Power | Stock Options

Class of Stock [Line Items]

Expected life

6 years 3 months

Option grants in period

200,000

Fair value of option grants

$ 39,530

Weighted Average Exercise Price Granted (usd per share)

$ 0.52

Fair Value Assumptions Risk Free Interest Rate

2.02%

Expected volatility

34.90%

Grant Three | Executive Officer | EuroSite Power | Stock Options

Class of Stock [Line Items]

Expected life

6 years 3 months

Option grants in period

100,000

Fair value of option grants

$ 14,194

Weighted Average Exercise Price Granted (usd per share)

$ 0.40

Fair Value Assumptions Risk Free Interest Rate

2.11%

Expected volatility

31.70%

Director Loan [Member] | EuroSite Power

Class of Stock [Line Items]

Interest rate

1.85%

Director Loan [Member] | Director | EuroSite Power

Class of Stock [Line Items]

Proceeds from note payable

$ 3,000,000

Prepayments of note payable

1,000,000

Note payable, related party

2,000,000

Accrued interest

28,000

Equity Exchange Agreement [Member] | IN Holdings Corp

Class of Stock [Line Items]

Stock Repurchased and Retired During Period, Shares

1,320,000

Noncontrolling Interest, Increase from Sale of Parent Equity Interest, Shares

1,320,000

Fair value of common stock issued in conjunction with exchange of EuroSite common stock

$ 1,320

Discontinued Operations | Noncontrolling Interest

Class of Stock [Line Items]

Fair value of common stock issued in conjunction with exchange of EuroSite common stock

$ 16,570

Stockholders' equity (Summary o

Stockholders' equity (Summary of Warranty Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Number of Warrants Outstanding [Roll Forward]
Number of Warrants Outstanding, Beginning (in shares)	3,449,770	507,500
Number of Warrants Granted (in shares)	0	2,942,270
Number of Warrants Exercised (in shares)	0	0
Number of Warrants Expired (in shares)	(500,000)	0
Number of Warrants Outstanding, Ending (in shares)	2,949,770	3,449,770
Weighted Average Grant Date Fair Value [Roll Forward]
Weighted Average Grant Date Fair Value Outstanding, Beginning (usd per share)	$ 2.09	$ 3.24
Weighted Average Grant Date Fair Value Granted (usd per share)	0	1.89
Weighted Average Grant Date Fair Value Exercised (usd per share)	0	0
Weighted Average Grant Date Fair Value Expired (usd per share)	3.25	0
Weighted Average Grant Date Fair Value Outstanding, Ending (usd per share)	$ 1.89	$ 2.09

Stockholders' equity (Summary46

Stockholders' equity (Summary of Weighted Average Assumptions Used In Black Scholes Option Pricing Model) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Expected life	6 years 3 months	6 years 3 months
Risk-free interest rate	2.09%	2.03%
Expected volatility	72.90%	68.80%

Stockholders' equity (Summary47

Stockholders' equity (Summary of Stock Option Activity) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
American DG Energy
Stock Options, Outstanding [Roll Forward]
Number of Options Outstanding Beginning (in shares)	3,119,000
Number of Options Granted (in shares)	200,000
Number of Options Exercised (in shares)	0
Number of Options Canceled (in shares)	(535,000)
Number of Options Expired (in shares)	(306,000)
Number of Options Outstanding, Ending (in shares)	2,478,000	3,119,000
Number of Option Exercisable, Ending (shares)	1,308,000
Number of Option Vested and expected to vest, ending (in shares)	2,478,000
Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price Outstanding, Beginning (usd per share)	$ 1.32
Weighted Average Exercise Price Granted (usd per share)	0.41
Weighted Average Exercise Price Exercised (usd per share)	0
Weighted Average Exercise Price Cancelled (usd per share)	1.42
Weighted Average Exercise Price Expired (usd per share)	2.59
Weighted Average Exercise Price Outstanding, Ending (usd per share)	1.06	$ 1.32
Weighted Average Exercise Price Exercisable, Ending (usd per share)	1.22
Weighted Average Exercise Price Vested and expected to vest, ending (usd per share)	$ 1.06
Options, Additional Disclosures [Abstract]
Weighted Average Remaining Life Outstanding, Beginning	4 years 11 months 6 days	5 years 1 month 25 days
Weighted Average Remaining Life Outstanding, Ending	4 years 11 months 6 days	5 years 1 month 25 days
Aggregate Intrinsic Value Outstanding, Beginning	$ 25,600
Aggregate Intrinsic Value Outstanding, Ending	4,000	$ 25,600
Aggregate intrinsic value Exercisable	0
Aggregate Intrinsic value Vested and expected to vest	$ 4,000
EuroSite Power
Stock Options, Outstanding [Roll Forward]
Number of Options Outstanding Beginning (in shares)	4,305,000
Number of Options Granted (in shares)	400,000
Number of Options Exercised (in shares)	0
Number of Options Canceled (in shares)	(595,000)
Number of Options Expired (in shares)	0
Number of Options Outstanding, Ending (in shares)	4,110,000	4,305,000
Number of Option Exercisable, Ending (shares)	3,442,500
Number of Option Vested and expected to vest, ending (in shares)	4,110,000
Options, Additional Disclosures [Abstract]
Weighted Average Remaining Life Outstanding, Beginning		6 years 10 months 1 day
Weighted Average Remaining Life Outstanding, Ending		6 years 10 months 1 day
Stock Options | EuroSite Power
Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price Outstanding, Beginning (usd per share)	$ 0.87
Weighted Average Exercise Price Granted (usd per share)	0.70	$ 0.65
Weighted Average Exercise Price Exercised (usd per share)	0
Weighted Average Exercise Price Cancelled (usd per share)	0.88
Weighted Average Exercise Price Expired (usd per share)	0
Weighted Average Exercise Price Outstanding, Ending (usd per share)	0.84	$ 0.87
Weighted Average Exercise Price Exercisable, Ending (usd per share)	0.89
Weighted Average Exercise Price Vested and expected to vest, ending (usd per share)	$ 0.84
Options, Additional Disclosures [Abstract]
Weighted Average Remaining Life Outstanding, Beginning	6 years 23 days
Weighted Average Remaining Life Outstanding, Ending	6 years 23 days
Aggregate Intrinsic Value Outstanding, Beginning	$ 9,800
Aggregate Intrinsic Value Outstanding, Ending	410,500	$ 9,800
Aggregate intrinsic value Exercisable	208,125
Aggregate Intrinsic value Vested and expected to vest	$ 410,500

Stockholders' equity (Changes i

Stockholders' equity (Changes in Company's Ownership Interest in its Subsidiary EuroSite Power) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Subsidiary or Equity Method Investee [Line Items]
Net Income (Loss) Attributable to Parent	$ (5,430,403)	$ (5,888,894)
Fair value of common stock issued in conjunction with exchange of EuroSite common stock	0
Impact of exchange resulting from ADGNY reorganization	(732,016)
Transfers (to) from noncontrolling interest:
Ownership changes to noncontrolling interest	50,057
Subtotal transfers (to) from noncontrolling interest	(320,386)	5,885,145
Change from net loss attributable to American DG Energy Inc. and transfers (to) from noncontrolling interest	$ (5,750,789)	(3,749)
Increase (Decrease) in Subsidiary Stock Held By Company, Shares	9,409,000
Subsidiary Common Stock and Warrants Sold, Shares	3,000,000
Reacquisition of Subsidiary Stock by Subsidiary, Shares	100,000
Conversion of Subsidiary Convertible Debentures into Subsidiary Common Stock, Shares	6,100,000
Additional Paid-in Capital
Subsidiary or Equity Method Investee [Line Items]
Fair value of common stock issued in conjunction with exchange of EuroSite common stock	$ (15,250)
Impact of exchange resulting from ADGNY reorganization	(732,116)
Transfers (to) from noncontrolling interest:
Ownership changes to noncontrolling interest	426,980	4,704,500
Increase in American DG Energy Inc.'s additional paid-in-capital for sale by EuroSite Power of 3,000,000 common shares and warrants		1,486,329
Decrease in American DG Energy Inc.'s additional paid-in-capital for reacquisition by EuroSite Power of 100,000 of its common shares		(42,902)
Increase in American DG Energy Inc.'s additional paid-in-capital for conversion of EuroSite Power convertible debentures into 6,100,000 common shares of EuroSite Power		2,455,377
Noncontrolling interest share of transactions affecting subsidiary ownership	$ 426,980	$ (2,718,159)

Warrant liability (Details)

Warrant liability (Details) - $ / shares	Dec. 09, 2010	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Warrants Issued During Period	500,000
Warrants, Exercise Price Per Share	$ 3.25
Warrants Expiration Term	5 years
Warrants Expiration Date		Dec. 14, 2015
Warrant Liability, Period to Determine Volatility Rate		30 days
Expected Volitility, Maximum Rate		70.00%

Employee benefit plan (Details)

Employee benefit plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Maximum employer annual contribution per employee, percent	4.50%
Company contributions to the plan during the year, dollars	$ 52,469	$ 49,816

Related parties (Details)

Related parties (Details) - USD ($)	Oct. 23, 2009	Jul. 31, 2012	Jan. 31, 2006	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Jul. 07, 2015
Related Party Transaction [Line Items]
Related party transactions agreement term						1 year
Related party agreement, period for notice termination		60 days
Tecogen
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party				$ 1,956,731	$ 1,432,801
Related party transactions agreement term			1 year
Rental income related party				$ 5,122
Ilois
Related Party Transaction [Line Items]
Related party transactions agreement term	5 years
Director
Related Party Transaction [Line Items]
Note payable, related party							$ 1,000,000
Interest rate							6.00%

Fair value measurements (Detail

Fair value measurements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Derivative Liabilities, Noncurrent	$ 0	$ 6,780
Fair Value Assumptions Expected Volatility Rate	72.90%	68.80%
Fair Value Assumptions Risk Free Interest Rate	2.09%	2.03%
Fair Value Assumptions Expected Term (in Years)	6 years 3 months	6 years 3 months
Fair Value Inputs, Discount Rate	5.61%
Gain attributable to distribution of nonmonetary assets to noncontrolling interest	$ 157,870	$ 0
Fair Value, Inputs, Level 3 | Warrant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Assumptions Expected Volatility Rate		57.00%
Fair Value Assumptions Risk Free Interest Rate		2.08%
Fair Value Assumptions Expected Term (in Years)		5 years
American DG New York, LLC
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Inputs, Discount Rate	15.00%
Fair value of assets transferred to AES-NJ			$ 632,016
Assets transferred to AES-NJ			$ 474,146
Gain attributable to distribution of nonmonetary assets to noncontrolling interest	$ 157,870

Fair value measurements (Summar

Fair value measurements (Summary of Activity for the Period) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at December 31, 2014	$ 6,780
Fair value adjustment at December 14, 2015	(6,780)
Fair value at December 31, 2015	$ 0

Income taxes (Loss from Operati

Income taxes (Loss from Operations) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Domestic	$ (4,731,000)	$ (5,310,000)
Foreign	(1,304,000)	(1,224,000)
Loss from operations before income taxes	$ (6,035,000)	$ (6,534,000)

(Reconciliation of Federal Stat

(Reconciliation of Federal Statutory Income Tax Provision To Company's Actual Provision) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Line Items]
Income tax provision	$ 27,605	$ 3,877
Benefit for Income Taxes
Income Tax Disclosure [Line Items]
Benefit at federal statutory tax rate	(2,052,000)	(2,222,000)
Foreign rate differential	209,000	159,000
UK Energy Incentives	(380,000)	(649,000)
Unbenefited operating losses	1,843,000	2,063,000
Provision for income taxes	37,000	4,000
Income tax provision	(343,000)	(645,000)
EuroSite Power
Income Tax Disclosure [Line Items]
Income tax provision	$ (380,176)	$ (648,917)

Income taxes (Schedule of Defer

Income taxes (Schedule of Deferred Tax Assets) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 11,875,000	$ 10,838,000
Accrued expenses and other	57,000	100,000
Stock compensation	1,312,000	1,194,000
Depreciation	357,000	(216,000)
Deferred tax assets and liabilties, net, before valuation allowance	13,601,000	11,916,000
Valuation allowance	(13,601,000)	(11,916,000)
Net deferred tax asset	$ 0	$ 0

Income taxes (Details)

Income taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Excess stock compensation deductions related to the amount of tax deductions on restricted stock in excess of book compensation expense	$ 1,353,000
Increase in valuation allowance	1,685,000	$ 1,316,000
United Kingdom energy tax incentive benefit recognized	377,988	$ 636,661
Federal
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	27,258,000
State
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	25,646,000
Foreign
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 4,734,000

Commitments and Contingencies (

Commitments and Contingencies (Details)	12 Months Ended
	Jun. 30, 2014USD ($)	Jul. 01, 2013ft²
Commitments and Contingencies Disclosure [Abstract]
Related party transactions agreement term	1 year
Related Party Agreement, Original Square Feet		3,282
Related Party Agreement, Square Feet		2,400
Related Party Transaction, Rent Expense | $	$ 5,122

Subsequent events Subsequent Ev

Subsequent events Subsequent Events (Details)	Nov. 01, 2016	Sep. 30, 2016USD ($)shares	Jun. 28, 2016USD ($)$ / sharesshares	May 04, 2016USD ($)shares	Aug. 06, 2014shares	May 30, 2016USD ($)shares	Sep. 30, 2016USD ($)	May 10, 2016$ / shares	Mar. 31, 2016
Subsequent Event
Subsequent Event [Line Items]
Premium over share closing price (percent)	27.00%
6% Convertible Debentures | Subsequent Event
Subsequent Event [Line Items]
Interest rate on convertible debt (percent)		6.00%		6.00%
Amount of debt converted to equity				$ 8,600,000
Subsidiaries | Subsequent Event
Subsequent Event [Line Items]
Percentage of ownership In subsidiary									48.00%
Subsidiaries | 6% Convertible Debentures | Subsequent Event
Subsequent Event [Line Items]
Shares issued in conversion of debt (shares) | shares		15,200,000		14,720,000
Ownership interest in subsidiary exchanged in conversion of debt (percent)				46.00%
Interest rate on convertible debt (percent)		6.00%
Amount of debt converted to equity		$ 6,700,000					$ 16,000,000
Convertible debt		10,100,000		$ 19,400,000			10,100,000
Face amount		$ 3,418,681					$ 3,418,681
Affiliated Entity | Private Placement | Subsidiaries | Subsequent Event
Subsequent Event [Line Items]
Shares issued in private placement (shares) | shares						12,608,696
Proceeds from private placement						$ 7,250,000
Share price (dollars per share) | $ / shares								$ 0.575
Board of Directors Chairman | Private Placement | Subsidiaries | Subsequent Event
Subsequent Event [Line Items]
Payment on related party note						$ 2,000,000
EuroSite Power | Affiliated Entity | Subsequent Event
Subsequent Event [Line Items]
Shares issued in conversion of debt (shares) | shares			3,909,260
Amount of debt converted to equity			$ 2,100,000
Convertible debt, related party			$ 2,400,000
Share price (dollars per share) | $ / shares			$ 0.54
Accrued interest on convertible debt, converted to shares			$ 11,000
Contractual conversion price (dollars per share) | $ / shares			$ 0.60
Conversion of convertible debt expense			$ 224,782
Common Stock
Subsequent Event [Line Items]
Shares issued in private placement (shares) | shares					2,650,000
Common Stock | Subsequent Event
Subsequent Event [Line Items]
Conversion ratio of American DG shares to Tecogen shares	0.092