American DG Energy (ADGE) 10-K 9 Apr 14 2013 FY Annual report Financial data

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION (USD $)	12 Months Ended
	Dec. 31, 2013	Mar. 31, 2014	Jun. 28, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'AMERICAN DG ENERGY INC	'	'
Entity Central Index Key	'0001378706	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Smaller Reporting Company	'	'
Trading Symbol	'adge	'	'
Entity Common Stock, Shares Outstanding	'	49,817,920	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Period Focus	'FY	'	'
Document Fiscal Year Focus	'2013	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Public Float	'	'	$36,569,800

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Dec. 31, 2012
ASSETS	'	'
Cash and cash equivalents	$9,804,291	$13,362,919
Accounts receivable, net	988,420	761,678
Unbilled revenue	12,765	19,492
Due from related party	304,288	18,372
Inventory	2,246,335	2,920,444
Prepaid and other current assets	196,939	308,164
Total current assets	13,553,038	17,391,069
Property, plant and equipment, net	21,931,289	17,253,648
Accounts receivable, long-term	45,200	46,800
Other assets, long-term	54,768	47,216
TOTAL ASSETS	35,584,295	34,738,733
LIABILITIES AND STOCKHOLDERS’ EQUITY	'	'
Accounts payable	871,079	765,618
Accrued expenses and other current liabilities	622,568	532,420
Due to related party	178,216	41,812
Capital lease obligations	0	3,365
Total current liabilities	1,671,863	1,343,215
Long-term liabilities:	'	'
Convertible debentures	17,172,807	17,000,000
Convertible debentures due related parties	4,525,573	2,400,000
Warrant liability	132,265	389,454
Other long-term liabilities	15,876	29,444
Total liabilities	23,518,384	21,162,113
Stockholders’ equity:	'	'
Common stock, $0.001 par value; 100,000,000 shares authorized; 49, 817, 920 and 48, 490, 733 issued and outstanding at December 31, 2013 and 2012, respectively	49,818	48,491
Additional paid-in capital	40,110,305	37,001,439
Accumulated deficit	-29,343,517	-24,456,845
Total American DG Energy Inc. stockholders’ equity	10,816,606	12,593,085
Noncontrolling interest	1,249,305	983,535
Total stockholders’ equity	12,065,911	13,576,620
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$35,584,295	$34,738,733

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Common stock, par value (usd per share)	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	49,817,920	48,490,733
Common stock, shares outstanding	49,817,920	48,490,733

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Revenues	'	'
Energy revenues	$7,164,226	$5,388,395
Turnkey & other revenues	297,654	256,799
Sales Revenue, Net, Total	7,461,880	5,645,194
Cost of sales	'	'
Fuel, maintenance and installation	4,862,905	3,487,223
Depreciation expense	1,382,693	1,698,014
Cost of Goods and Services Sold, Total	6,245,598	5,185,237
Gross profit	1,216,282	459,957
Operating expenses	'	'
General and administrative	2,940,833	2,770,535
Selling	1,383,077	1,919,075
Engineering	1,018,914	1,165,286
Operating Expenses, Total	5,342,824	5,854,896
Loss from operations	-4,126,542	-5,394,939
Other income (expense)	'	'
Interest and other income	49,291	62,322
Interest expense	-1,292,766	-1,270,694
Change in fair value of warrant liability	257,189	-139,893
Nonoperating Income (Expense), Total	-986,286	-1,348,265
Loss before provision for income taxes	-5,112,828	-6,743,204
Provision for income taxes	-13,450	-24,550
Consolidated net loss	-5,126,278	-6,767,754
Loss attributable to the noncontrolling interest	239,606	241,967
Net loss attributable to American DG Energy Inc.	($4,886,672)	($6,525,787)
Net loss per share - basic and diluted (usd per share)	($0.10)	($0.14)
Weighted average shares outstanding - basic and diluted (in shares)	48,932,838	47,108,980

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock $0.001 Par Value	Additional Paid-in Capital	Accumulated Deficit	Noncontrolling Interest
Balance, Beginning Balance at Dec. 31, 2011	$13,380,471	$46,001	$30,399,370	($17,931,058)	$866,158
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'
Distributions to noncontrolling interest	-322,974	'	'	'	-322,974
Ownership changes to noncontrolling interest	106,408	'	'	'	106,408
Sale of common stock, net of costs	3,535,038	2,250	3,532,788	'	'
Sale of subsidiary common stock, net of costs	2,139,293	'	1,650,239	'	489,054
Purchase of common stock, net of costs	-750,000	-500	-749,500	'	'
Issuance of common stock warrants	7,500	'	7,500	'	'
Conversion of convertible debenture interest to common stock	1,237,470	502	1,236,968	'	'
Stock based compensation expense	810,285	'	723,429	'	86,856
Exercise of stock options	200,923	278	200,645	'	'
Cancellation of restricted stock	-40	-40	'	'	'
Net loss	-6,767,754	'	'	-6,525,787	-241,967
Balance, Ending Balance at Dec. 31, 2012	13,576,620	48,491	37,001,439	-24,456,845	983,535
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'
Distributions to noncontrolling interest	-311,664	'	'	'	-311,664
Ownership changes to noncontrolling interest	559,500	'	'	'	559,500
Sale of common stock, net of costs	952,333	634	951,699	'	'
Eurosite stock dividend to ADG investors	0	'	-199,408	'	199,408
Conversion of convertible debenture interest to common stock	1,170,051	693	1,169,358	'	'
Fair value of conversion option	649,000	'	649,000	'	'
Stock based compensation expense	596,349	'	538,217	'	58,132
Net loss	-5,126,278	'	'	-4,886,672	-239,606
Balance, Ending Balance at Dec. 31, 2013	$12,065,911	$49,818	$40,110,305	($29,343,517)	$1,249,305

CONSOLIDATED_STATEMENTS_OF_STO1

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY Parenthetical (USD $)	Dec. 31, 2013	Nov. 25, 2013	25-May-13	Dec. 31, 2012	Nov. 25, 2012	25-May-12
Statement of Stockholders' Equity [Abstract]	'	'	'	'	'	'
Common Stock, $0.001 Par Value	$0.00	$1.54	$1.84	$0.00	$2.33	$2.22

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net loss	($4,886,672)	($6,525,787)
Loss attributable to noncontrolling interest	-239,606	-241,967
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	1,471,914	1,754,279
Provision for losses on accounts receivable	235,638	123,880
Amortization of deferred financing costs	10,224	20,448
Increase (decrease) in fair value of warrant liability	-257,189	139,893
Noncash interest expense	1,170,051	1,237,470
Stock-based compensation	596,349	810,285
Changes in operating assets and liabilities:	'	'
Accounts receivable and unbilled revenue	-454,053	29,269
Due from related party	-285,916	2,768
Inventory	674,109	-2,286,324
Prepaid and other current assets	93,449	-48
Increase (decrease) in:	'	'
Accounts payable	105,461	245,010
Accrued expenses and other current liabilities	90,148	-56,612
Due to related party	136,404	-272,035
Other long-term liabilities	-13,568	-13,608
Net cash used in operating activities	-1,553,257	-5,033,079
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-5,590,055	-4,211,402
Net cash used in investing activities	-5,590,055	-4,211,402
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Proceeds from issuance of convertible debentures	2,947,380	0
Proceeds from issuance of warrants	0	7,500
Proceeds from sale of common stock, net of costs	952,333	3,535,038
Proceeds from sale of subsidiary common stock, net of costs	0	2,139,293
Proceeds from exercise of stock options	0	200,923
Purchases of common stock, net of costs	0	-750,000
Convertible debenture transaction costs	0	0
Principal payments on capital lease obligations	-3,365	-3,365
Cancellation of restricted stock	0	-40
Distributions to noncontrolling interest	-311,664	-322,974
Net cash provided by financing activities	3,584,684	4,806,375
Net (decrease) increase in cash and cash equivalents	-3,558,628	-4,438,106
Cash and cash equivalents, beginning of the period	13,362,919	17,801,025
Cash and cash equivalents, end of the period	9,804,291	13,362,919
Supplemental disclosures of cash flows information:	'	'
Income taxes	68,762	46,462
Interest	115,635	'
Non-cash investing and financing activities:	'	'
Conversion of convertible debenture interest into common stock	1,164,000	1,141,000
Convertible debenture interest adjustment	$6,051	$96,470

The_Company

The Company	12 Months Ended
	Dec. 31, 2013
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. As of December 31, 2013, the Company had installed 109 energy systems.
	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, 2013, the Company had 109 energy systems operational. As a by-product of its energy business, in some cases the customer may choose to have us construct the system for them rather than have it owned by American DG Energy.

Summary_of_significant_account

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2013
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 include the accounts of the Company, its wholly-owned subsidiary American DG Energy, its 51.0% joint venture, American DG New York, LLC, or ADGNY, and its 70.7% owned subsidiary EuroSite Power Inc., or EuroSite Power. The Company’s owns 51.0% of ADGNY, after elimination of all material intercompany accounts, transactions and profits. The interest in underlying energy system projects in the joint venture varies 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 and profitability of the joint venture and underlying energy projects. 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, Peter Westerhoff, each quarter. On the Company’s balance sheet, noncontrolling interest represents the partner’s investment in the entity, plus its share of after tax profits less any cash distributions. The Company owned a controlling 51.0% legal interest and a 62.5% economic interest in ADGNY as of December 31, 2013.
	In July 2010, the Company invested $45,000 in exchange for 45 million shares of EuroSite Power, a newly established corporation. The investment gave the Company a controlling financial interest in EuroSite Power, whose business focus is to introduce the On-Site Utility solution into the European market. Also in July 2010, Nettlestone Enterprises Limited, invested $5,000 in exchange for 5 million shares in EuroSite Power. In 2011, EuroSite Power raised approximately $1,250,000 in private placements by selling 1,250,000 shares of its common stock to accredited investors at $1.00 per share. In March 2012, EuroSite Power issued 851,100 shares to its existing stockholders in connection with a 10.0% stock dividend and in November 2012, EuroSite Power raised approximately $2,385,000 in a public offering and private placement by selling 2,385,000 shares of its common stock and 2,507,525 warrants, including placement agent warrants, to accredited investors at $1.00 per share.
	On July 2, 2013, the Company declared a special dividend of one share of EuroSite Power common stock for every ten shares of American DG Energy common stock (“special dividend”). The special dividend was paid on August 15, 2013, to stockholders of record as of the close of business on July 25, 2013. In connection with this transaction, the Company issued to its stockholders an aggregate of 4,880,679 shares of EuroSite Power common stock that it owns.
	As of December 31, 2013, the Company owns a 70.7% interest in EuroSite Power and has consolidated EuroSite Power into its financial statements in accordance with generally accepted accounting principles, or GAAP.
	On February 10, 2012, EuroSite Power announced that its Board of Directors declared a stock dividend of 10.0% per share on the outstanding shares of EuroSite Power common stock. The dividend was payable on March 12, 2012 to common stockholders of record at the close of business on February 24, 2012. The Company rejected the receipt of the dividend on the EuroSite Power shares it held at that time. Prior to that transaction, EuroSite Power had paid no cash or stock dividends on its common stock.
	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 revenue is generated in the United States of America and in the United Kingdom. During the years ended December 31, 2013 and 2012 revenue generated in the United States amounted to $6,623,001 and $5,564,084 respectively and revenue generated in the United Kingdom amounted to $838,879 and $81,110 respectively.  At December 31, 2013, $17,900,959 of the Company’s long lived assets were located in the United States of America and $4,030,330 were located in the United Kingdom.  At December 31, 2012, $15,726,700 of the Company’s long lived assets were located in the United States of America and $1,526,948 were located in the United Kingdom.
	The Company has experienced total net losses since inception of approximately $29.3 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 March 31, 2015, 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.
	In 2012, the Company raised $3,535,038, net of issuance costs, from common stock and convertible debt. If the Company is unable to raise additional capital in 2015 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 by-product of the energy business, in some cases, the customer may choose to have the Company construct the system for them 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. The Company had no such arrangements in the years ended December 31, 2013 and 2012, respectively.
	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 had no such arrangements in the years ended December 31, 2013 and 2012, respectively.
	Occasionally, the Company will enter into a sales arrangement with a customer to construct and sell an energy system and provide energy and maintenance services over the term of the contract. Based on the fact that the Company sells each deliverable to other customers on a stand-alone basis, the Company has determined that each deliverable has a stand-alone value. Additionally, there are no rights of return relative to the delivered items; therefore, each deliverable is considered a separate unit of accounting. Revenue is allocated to each element based upon its relative selling price which is determined based on the estimated price of the deliverables when sold on a standalone basis. Revenue related to the construction of the energy system is recognized using the percentage-of-completion method as the unit is being constructed. Revenue from the sale of energy is recognized when electricity, heat, and chilled water is produced by the energy system, and revenue from maintenance services is recognized over the term of the maintenance agreement. The Company had no such arrangements at December 31, 2013 and 2012, respectively.
	The Company is able to participate in the demand response market and receive payments due to the availability of its energy systems. Demand response programs provide 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 year ended December 31, 2013 and 2012, the revenue recognized from demand response activity was $112,405 and $106,340, respectively. The Company treats demand response payments as an operating activity in the statements of cash flows.
	Other revenue represents various types of ancillary activities for which the Company engages from time to time such as the sale of equipment, and feasibility studies.
	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, 2013, the Company had a balance of $8,554,191 in cash and cash equivalents that exceeded the Federal Deposit Insurance Corporation limit.
	During the years ended December 31, 2013 and 2012 one customer accounted for 12% and 15% of revenue, respectively.
	Accounts Receivable
	The Company maintains receivable balances primarily with customers located throughout New York and New Jersey. 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 when identified.
	At December 31, 2013 and 2012, the allowance for doubtful accounts was $183,201 and $54,000, respectively. Included in accounts receivable are amounts from four major customers accounting for approximately 35.0% and 29.0% of total accounts receivable for the years ended December 31, 2013 and 2012, respectively. There were sales to four major customers accounting for approximately 25.0% and 32.0% of total sales for the years ended December 31, 2013 and 2012, respectively.
	Inventory
	Inventories 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, 2013 and 2012, there were no reserves or write-downs recorded against inventory.
	Accounts Payable
	Included in accounts payable are amounts due to four major vendors accounting for approximately 30.0% and 34.0% of total accounts payable for the years ended December 31, 2013 and 2012, respectively. Purchases from four vendors accounted for approximately 35.0% and 47.0% of total purchases for the years ended December 31, 2013 and 2012, respectively.
	Supply Concentrations
	All of the Company’s cogeneration unit purchases for the years ended December 31, 2013 and 2012 were from one vendor (see “Note 8 - 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. 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 and Depreciation and Amortization
	Property 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 the useful life of its energy systems on a quarterly basis or 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 impairment is indicated by comparing the 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 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.
	The Company receives rebates and incentives from various utility companies 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 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 2013 and 2012, the amount of rebates applied to the cost of construction was $285,718 and $583,800, 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 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 5 – 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, 2013 and 2012, 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, 2013, the Company excluded 12,088,313 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, 2012, the Company excluded 11,445,182 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.
	Other Comprehensive Net Loss
	The comprehensive net loss for the years ended December 31, 2013 and 2012 does not differ from the reported 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. In addition, the Company is required to provide a tabular reconciliation of the change in the aggregate unrecognized tax benefits claimed, or expected to be claimed, in tax returns and disclosure relating to the accrued interest and penalties for unrecognized tax benefits. Discussion is also required for those uncertain tax positions where it is reasonably possible that the estimate of the tax benefit will change significantly in the next twelve months.
	The tax years 2003 through 2005 and 2010 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, 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 warrant liability is recorded at fair value. The carrying value of the convertible debentures on the balance sheet at December 31, 2013 approximates fair value as the terms approximate those currently available for similar instruments. See “Note 9 - Fair value measurements.”
	Impact of New Accounting Pronouncements
	The Company does not expect the impact of recently issued accounting pronouncements to have a material impact on the Company's results of operation, financial position, or cash flows.

Property_plant_and_equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Property, plant and equipment	'
	Property, plant and equipment:
	Property, plant and equipment consist of the following as of December 31, 2013 and 2012, respectively:
		2013			2012
	Energy Systems	$	25,567,808		$	19,052,933
	Computer equipment and software	122,853			109,910
	Furniture and fixtures	85,079			81,435
	Vehicles	243,139			166,193
		26,018,879			19,410,471
	Less — accumulated depreciation	(7,621,242		)	(6,149,328		)
		18,397,637			13,261,143
	Construction in progress	3,533,652			3,992,505
		$	21,931,289		$	17,253,648
	Depreciation expense of property, plant and equipment totaled $1,471,914 and $1,754,279 for the years ended December 31, 2013 and 2012, respectively.

Convertible_debentures

Convertible debentures	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Convertible debentures	'
	Convertible debentures:
	American DG Energy Convertible Debentures
	On May 23, 2011, the Company issued $12,500,000 aggregate principal amount of debentures to a European investor and to John N. Hatsopoulos, the Company’s Chief Executive Officer. The debentures mature on May 25, 2018 and accrue interest at the rate of 6.0% per annum payable 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 $2.20 per share, subject to adjustment in certain circumstances. The Company has the option to redeem at 115% of Par Value any or all of the debentures after May 25, 2016. The debentures canceled the revolving line of credit agreement with John N. Hatsopoulos, which as of May 23, 2011 had a principal amount outstanding of $2,400,000.
	On November 30, 2011, the Company issued an additional $6,900,000 aggregate principal amount of debentures to the European investor. The debentures mature on May 25, 2018 and accrue interest at the rate of 6.0% per annum payable 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 $2.20 per share, subject to adjustment in certain circumstances. The Company has the option to redeem at 115% of Par Value any or all of the debentures after May 25, 2016.
	On March 22, 2012, the debenture holders amended the terms on the debentures with respect to the interest payment and agreed to receive their interest payment in shares of the Company's common stock instead of cash for 2012, 2013 and 2014, provided that the Company's shares are listed on a National Securities Exchange. Under the terms of the agreement, for the May semi-annual interest payment, the Company used the April average daily closing price of the common stock in order to determine the conversion price. All other terms and conditions, including interest rate and maturity date remained the same.
	On May 25, 2012, the total interest due to the debenture holders was $559,000 and in connection with the amendment the Company issued to the debenture holders 251,917 shares of common stock at $2.22 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 $153,921 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2012.
	On September 28, 2012, the debenture holders amended the terms on the debentures with respect to the interest payment and agreed to receive their interest payment in shares of the Company's common stock instead of cash for 2012, 2013 and 2014, provided that the Company's shares are listed on a National Securities Exchange. Under the terms of the agreement, the Company will use the average daily closing price of the Common Stock 10 business days before the interest payment date (May 25th and November 25th) in order to determine the conversion price. All other terms and conditions, including interest rate and maturity date remain the same.
	On November 25, 2012, the total interest due to the debenture holders was $582,000 and in connection with the amendment the Company issued to the debenture holders 249,787 shares of common stock at $2.33 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 a reduction of $57,451 of non-cash interest expense, which was the difference between the average stock price and the fair market value on November 25, 2012.
	On January 10, 2013, at the request of all holders of the Company’s Senior Unsecured Convertible Debentures, due 2018, the Company modified through a third amendment the terms of the interest payment due to the holders. Under the terms of the third amendment, the holders agreed to receive interest payments on an annual basis starting on November 25, 2013 (instead of semi-annual interest payments) and that the Company use the average daily closing price of the Common Stock 10 business days before the interest payment due date in order to determine the conversion price. All other terms and conditions of the Debentures, including interest rate and maturity date remained the same.
	On May 24, 2013, at the request of all holders of the Company’s Senior Unsecured Convertible Debentures, due 2018, the Company modified through a fourth amendment the terms of the interest payment due to the holders. Under the terms of the fourth amendment, the holders agreed to receive semi-annual interest payments on May 25th and November 25th in shares of the Company's common stock instead of cash for 2012, 2013 and 2014, provided that the Company's shares are listed on a National Securities Exchange. Under the terms of this amendment, for the May semi-annual interest payment, the Company will use the April average daily closing price of the Common Stock in order to determine the conversion price and for the November semi-annual interest payment the Company will use the October average daily closing price of the Common Stock in order to determine the conversion price. All other terms and conditions of the Debentures, including interest rate and maturity date remained the same.
	On May 25, 2013, the total interest due to the debenture holders was $582,000 and in connection with the amendment the Company issued to the debenture holders 316,462 shares of common stock at $1.84 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 a reduction of $53,511 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2013.
	On July 2, 2013, the Company declared a special dividend of one share of EuroSite Power common stock for every ten shares of American DG Energy common stock (“special dividend”). The special dividend was paid on August 15, 2013, to stockholders of record as of the close of business on July 25, 2013. In connection with this transaction the Company, issued to its stockholders an aggregate of 4,880,679 shares of EuroSite Power common stock that it owns. Affiliates may sell the securities only after a 6 month holding period pursuant to the provisions of the SEC's Rule 144.
	On August 15, 2013, in connection with the special dividend, the Company modified the conversion price of the 6%, $19,400,000 debentures issued on May 23, 2011 and November 30, 2011 from $2.20 to $2.11 per share. The adjustment to the conversion price was not an automatic adjustment pursuant to the original terms of the debentures. Accordingly, the adjustment to the conversion price was accounted for as a modification under ASC 470. The modification of the convertible debt instrument resulted in an increase in the fair value of the embedded conversion option and the carrying amount of the debt instrument was reduced by approximately $649,000. This debt discount will be amortized over the remaining term of the debt. In accordance with ASC 820, the fair value of the conversion option at the date of modification was determined by utilizing a binomial lattice model with the following key assumptions:
	Company stock price	$1.64 per share
	Risk -free rate	1.43% - 1.45%
	Term	4.78 years
	Volatility	68.80%
	On November 25, 2013, the total interest due to the debenture holders was $582,000 and in connection with the amendment the Company issued to the debenture holders 377,391 shares of common stock at $1.54 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 $59,562 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2013.
	On September 30, 2013, the Company had a balance of $20,000 due to John N. Hatsopoulos related to interest payable on his outstanding convertible debentures.
	Eurosite Power Convertible Debenture
	On February 26, 2013, Eurosite issued a promissory note in the amount of $1,100,000 to the Company, its parent. Under the terms of the agreement Eurosite was to pay interest at a rate of 6.0% per annum payable quarterly in arrears.
	On June 14, 2013, Eurosite entered into subscription agreements with certain investors, including 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 for a like principal amount of the Notes and cash paid for any accrued but unpaid interest. Included among the investors subscribing for the Notes are: Bruno Meier, a director of EuroSite, in the amount of $250,000; Joan Giacinti, a director of the Company and EuroSite, 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 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.
	The proceeds of the offering of the Notes will be used in connection with the development and installation of current and new energy systems, business development and for general corporate purposes.
	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 will mature on June 14, 2015 and will 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'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 will 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 initially concluded that the term-extending option mentioned above was an embedded derivative with de minimis value but 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 no 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 below.
	The Noteholders Agreement provides for customary events of default by Eurosite, 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 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 the Company 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 will file a Form S-3 registration statement covering the Registrable Securities requested to be included in such registration, subject to adjustment.
	On February 20, 2014, EuroSite accepted certain separate note exchange agreements, or the Note Exchange Agreements, from the holders of its existing 4% Senior Convertible Notes Due 2015, originally issued on June 14, 2013, or the Notes, including the Company, pursuant to which EuroSite exchanged the Old 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 will be treated as accrued interest under the New Notes. Included among the investors exchanging their Notes for New Notes are: the Company, in the amount of $1,100,000; Bruno Meier, a director of EuroSite, 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 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; Yves Micheli, an investor in EuroSite Power, in the amount of $300,000.
	The holders of the Notes were subject to and entitled to the benefits of the Noteholders Agreement, and such agreement was amended by the Note Exchange Agreements. The Noteholders Agreement remains in effect as to the New Notes, except it has been amended to reflect the maturity of the New Notes as June 14, 2017; provide that the initial conversion rate of the New Notes is 1,667 shares of common stock per $1,000 principal amount of the New Notes, subject to adjustment; and eliminate the noteholders’ options to extend the Notes.

Stockholders_equity

Stockholders' equity	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Note [Abstract]	'
Stockholders' equity	'
	Stockholders’ equity:
	Common Stock
	On March 27, 2012, the Company entered into a definitive agreement to sell restricted common stock for aggregate proceeds of $1,600,000 to Dr. Phillip Frost through one of his trusts. Pursuant to the agreement, the Company sold to Dr. Frost 1,000,000 shares of restricted common stock at $1.60 per share. The proceeds of the private placement were used to fund additional installations of the Company's On-Site Utility energy systems and for general corporate and working capital purposes.
	On August 7, 2012, the Company entered into a definitive agreement to sell restricted common stock for aggregate proceeds of $2,000,000 to Dr. Phillip Frost through one of his trusts. Pursuant to the agreement, the Company sold to Dr. Frost 1,250,000 shares of restricted common stock at $1.60 per share. The proceeds of the private placement were used to fund additional installations of the Company's On-Site Utility energy systems and for general corporate and working capital purposes.
	The holders of common stock have the right to vote their interest on a per share basis. At December 31, 2013, there were 49,817,920 shares of common stock outstanding.
	On August 28, 2013, after the closing of trading on the NYSE-MKT, the Company, entered into a subscription agreement with Charles T. Maxwell, the Company's Chairman of the Board, or the Investor, selling to the Charles T. Maxwell IRA an aggregate of 300,000 shares of the Company's Common Stock, $.001 par value per share, or the Securities, at a purchase price of $1.55 per share for an aggregate purchase price of $465,000. Under this agreement, the Company was required at its own cost to file with the SEC a registration statement covering the resale of such shares. The proceeds of this private placement will be used to fund additional installations of the Company's On-Site Utility energy systems and for general corporate and working capital purposes. The Securities were offered and sold to the Investor in a private placement transaction made in reliance upon an exemption from registration pursuant to Section 4(a)(2) under the Securities Act of 1933, as amended, or the Securities Act. The Investor is an accredited investor as defined in Rule 501 of Regulation D promulgated under the Securities Act.
	On September 4, 2013, after the closing of trading on the NYSE-MKT, the Company, entered into a subscription agreement with Frost Gamma Investments Trust, or the Trust, an accredited investor, by selling to the Trust an aggregate of 333,334 shares of the Company's common stock at a per share price of $1.50 for an aggregate purchase price of $500,001. Under this agreement, the Company was required at its own cost to file with the SEC a registration statement covering the resale of such shares. The proceeds of this private placement will be used to fund additional installations of the Company's On-Site Utility energy systems and for general corporate and working capital purposes. The Securities were offered and sold to the Investor in a private placement transaction made in reliance upon an exemption from registration pursuant to Section 4(a)(2) under the Securities Act of 1933, as amended, or the Securities Act. The Investor is an accredited investor as defined in Rule 501 of Regulation D promulgated under the Securities Act.
	Warrants
	On February 22, 2012, the Company sold a warrant to purchase shares of the Company's common stock to an accredited investor, for a purchase price of $7,500. The warrant expired on February 22, 2013, and gave the investor the right but not the obligation to purchase 50,000 shares of the Company's common stock at an exercise price per share of $3.00. The expense related to this warrant was de minimis for the period ended December 31, 2013.
	At December 31, 2013, the Company had 507,500 warrants outstanding including, 500,000 warrants at an exercise price of $3.25 per share that expire on December 14, 2015 (see “Note 6 - Warrant liability” and “Note 9 - Fair value measurements”); and 7,500 warrants at an exercise price of $2.69 per share that expire on January 15, 2016.
	Warrant activity for the years ended December 31, 2013 and 2012 was as follows:
		Number of			Weighted Average
		Warrants			Grant Date
					Fair Value
	Unvested, December 31, 2011	588,000			$	3.12
	Granted	50,000			0.15
	Exercised	—			—
	Expired	(72,500	)		0.58
	Unvested, December 31, 2012	565,500			$	3.19
	Granted	—			—
	Exercised	—			—
	Expired	84,500			0.17
	Unvested, December 31, 2013	507,500			$	3.24
	Stock Based Compensation – American DG Energy
	The Company 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 the Company.
	The maximum number of shares of stock allowable for issuance under the Amended Plan is 5,000,000 shares of common stock. Stock options vest based upon the terms within the individual option grants, usually over a two- or ten-year period with an acceleration of the unvested portion of such options upon a liquidity event, as defined in the Company’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. In 2013, (5,000) options were canceled, (100,000) expired, and 430,000 options were granted. The number of securities remaining available for future issuance under the Amended Plan was 105,500 at December 31, 2013. See the Company's option table for further detail.
	During the years ended December 31, 2013 and 2012, the Company recognized employee non-cash compensation expense of $596,349 and $810,285, respectively, related to the issuance of stock options by the Company and EuroSite. At December 31, 2013, the total compensation cost related to unvested stock option awards, including EuroSite Power, not yet recognized is $740,221. This amount will be recognized over the weighted average period of 3 years.
	In 2012, the Company granted 300,000 nonqualified options to purchase shares of its common stock to two directors and 42,000 to five employees at prices ranging between $1.60 and $2.79 per share. Those options have a vesting schedule of 4 years and expire in 5 years. The fair value of all options issued in 2012 was $456,392, with a weighted average grant date fair value of $1.33 per option.
	In 2013, the Company issued 80,000 nonqualified stock options to one director and 350,000 nonqualified stock options to two employees at prices ranging between $1.54 and $1.67 per share. *150,000 of those options have a vesting schedule of 4 years and expire in 5 years. 280,000 of those options have vesting schedule of 4 years and expire in 10 years. The fair value of all options issued in 2013 was $368,044, with a weighted average grant date fair value of $0.86 per option.
	The weighted average assumptions used in the Black-Scholes option pricing model are as follows:
		2013			2012
	Stock options and restricted stock awards
	Expected life	5 years			5 years
	Risk-free interest rate	1.75	%		0.74	%
	Expected volatility	60.3	%		72.8	%
	Stock option activity for the years ended December 31, 2013 and 2012 was as follows:
	Common Stock Options	Number of Options		Weighted Average Exercise Price			Weighted Average Remaining Life	Aggregate Intrinsic Value
	Outstanding, December 31, 2011	2,008,375		$	1.15		4.87 years	$	1,055,319
	Granted	342,000		2.39
	Exercised	(277,625	)	0.72
	Canceled	(11,250	)	2.64
	Expired	—		—
	Outstanding, December 31, 2012	2,061,500		$	1.4		4.32 years	$	2,151,585
	Exercisable, December 31, 2012	1,047,250		$	1.09			$	1,366,918
	Vested and expected to vest, December 31, 2012	2,061,500		$	1.4			$	2,151,585
	Outstanding, December 31, 2012	2,061,500		$	1.4		4.32 years	$	2,151,585
	Granted	430,000		1.59
	Exercised	—		—
	Canceled	(5,000	)	1.4
	Expired	(100,000	)	0.07
	Outstanding, December 31, 2013	2,386,500		$	1.49		4.13 years	$	1,092,550
	Exercisable, December 31, 2013	1,241,750		$	1.36			$	753,550
	Vested and expected to vest, December 31, 2013	2,386,500		$	1.49			$	1,092,550
	The aggregate intrinsic value of options outstanding as of December 31, 2013 is calculated as the difference between the exercise price of the underlying options and the price of the Company’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.
	The Company did not make any restricted stock grants to employees in 2013 or 2012. The Company has no restricted stock outstanding in 2013 and 2012.
	Stock-Based Compensation – EuroSite Power
	In January 2011, EuroSite Power adopted the 2011 Stock Incentive Plan, or the Plan, under which the Board of Directors may grant up to 3,000,000 shares of incentive or non-qualified stock options and stock grants to key employees, directors, advisors and consultants of EuroSite Power. On June 13, 2011, the Board of Directors unanimously amended the Plan to increase the reserved shares of Common Stock issuable under the Plan from 3,000,000 to 4,500,000, or the Amended Plan.
	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 475,000 at December 31, 2013.
	On March 20, 2013, EuroSite Power granted to a director options to purchase 100,000 shares of Common Stock, to a consultant options to purchase 50,000 shares of Common Stock, and to six employees options to purchase 88,000 shares of common stock. Those options have a vesting schedule of 4 years and expire in 10 years.
	On October 15, 2013, EuroSite Power granted to its Chief Financial Officer 200,000 shares of common stock. Those options having a vesting schedule of 4 years and expire in 10 years.
	At December 31, 2013, EuroSite Power had 4,025,000 options outstanding and recognized employee non-cash compensation expense of $238,404 related to the issuance of those stock options. For the year ended December 31, 2013 the total compensation cost related to unvested stock option awards not yet recognized was $220,936. This amount will be recognized over the weighted average period of 2.94 years.
	Stock option activity for the years ended December 31, 2013 and 2012 was as follows:
	Common Stock Options	Number of Options		Weighted Average Exercise Price			Weighted Average Remaining Life		Aggregate Intrinsic Value
Outstanding, December 31, 2011	3,600,000		$	0.9		9.34 years		$	—
Granted	—		—
Exercised	—		—
Canceled	(10,000	)	0.9
Expired	—		—
Outstanding, December 31, 2012	3,590,000		$	0.9		8.34 years		$	359,000
Exercisable, December 31, 2012	897,500		$	0.9				$	89,750
Vested and expected to vest, December 31, 2012	3,590,000		$	0.9				$	359,000
Outstanding, December 31, 2012	3,590,000		$	0.9		8.34 years		$	359,000
Granted	438,000		0.67
Exercised	—		—
Canceled	(3,000	)	0.9
Expired	—		—			—		—
Outstanding, December 31, 2013	4,025,000		$	0.87		7.58 years		$	74,000
Exercisable, December 31, 2013	1,795,000		$	0.9				$	—
Vested and expected to vest, December 31, 2013	4,025,000		$	0.87				$	74,000
The aggregate intrinsic value of options outstanding as of December 31, 2013 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.

Warrant_liability

Warrant liability	12 Months Ended
	Dec. 31, 2013
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 expire 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 9 – Fair value measurements”).

Employee_benefit_plan

Employee benefit plan	12 Months Ended
	Dec. 31, 2013
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 $53,697 and $56,034 to the Retirement Plan for the years ended December 31, 2013 and 2012, respectively.

Related_parties

Related parties	12 Months Ended
	Dec. 31, 2013
Related Party Transactions [Abstract]	'
Related parties	'
	Related parties
	Eurosite Power, Tecogen, Ilios Inc., or Ilios, GlenRose Instruments Inc., or GlenRose Instruments, Pharos LLC, or Pharos, and Levitronix Technologies LLC, or Levitronix 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. Tecogen has a sublease agreement for the office building, which expired on March 31, 2014. The process of extending the sublease is ongoing.
	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 $6,495.
	The Company has granted Tecogen sales representation rights to its On-Site Utility energy service in California. During the year ended December 31, 2013, the Company received $0 from Tecogen as a commission from the sale of equipment.
	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. T The Amendment also increases the space provided to the Company by Tecogen from approximately 3,071 square feet to 3,282 square feet and from six offices to nine offices. Under the Amendment, the amount that the Company will pay Tecogen for the space and services that Tecogen provides under the Agreement increased to $6,495 per month. The Amendment 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.
	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 modifies the exclusivity arrangement of the Facilities, Support Services and Business Agreement between the Company and Tecogen to 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, ADG Energy will defer to the local representative for pricing and other specific details for working cooperatively.
	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. The Company has not yet sold any products under this agreement and, therefore, no amounts have been paid.
	On November 12, 2013, the Company entered into the First Amendment to the Sales Representative Agreement with Ilios Inc. 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 so long as the Company intends 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 May 23, 2011, the Company issued $12,500,000 aggregate principal amount of debentures to a European investor and to John N. Hatsopoulos, the Company’s Chief Executive Officer. The debentures mature on May 25, 2018 and accrue interest at the rate of 6.0% per annum payable 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 $2.20 per share, subject to adjustment in certain circumstances. The Company has the option to redeem at 115% of Par Value any or all of the debentures after May 25, 2016. The proceeds of the debentures will be used in connection with the development and installation of current and new energy systems, business development and for general corporate purposes. As of May 23, 2011, Mr. Hatsopoulos had a revolving line of credit agreement with the Company with an outstanding balance of $2,400,000. That balance was converted into the debentures and the revolving line of credit agreement was canceled.
	On November 30, 2011, the Company issued an additional $6,900,000 aggregate principal amount of debentures to the European investor. The debentures mature on May 25, 2018 and accrue interest at the rate of 6.0% per annum payable 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 $2.20 per share, subject to adjustment in certain circumstances. The Company has the option to redeem at 115% of Par Value any or all of the debentures after May 25, 2016.
	On March 22, 2012, the debenture holders amended the terms on the debentures with respect to the interest payment and agreed to receive their interest payment in shares of the Company's common stock instead of cash for 2012, 2013 and 2014, provided that the Company's shares are listed on a National Securities Exchange. Under the terms of the agreement, for the May semi-annual interest payment, the Company used the April average daily closing price of the common stock in order to determine the conversion price. All other terms and conditions, including interest rate and maturity date remained the same.
	On May 25, 2012, the total interest due to the debenture holders was $559,000 and in connection with the amendment the Company issued to the debenture holders 251,917 shares of common stock at $2.22 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 $153,921 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2012.
	On September 28, 2012, the debenture holders amended the terms on the debentures with respect to the interest payment and agreed to receive their interest payment in shares of the Company's common stock instead of cash for 2012, 2013 and 2014, provided that the Company's shares are listed on a National Securities Exchange. Under the terms of the agreement, the Company will use the average daily closing price of the Common Stock 10 business days before the interest payment date (May 25th and November 25th) in order to determine the conversion price. All other terms and conditions, including interest rate and maturity date remain the same.
	On November 25, 2012, the total interest due to the debenture holders was $582,000 and in connection with the amendment the Company issued to the debenture holders 249,787 shares of common stock at $2.33 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 a reduction of $57,451 of non-cash interest expense, which was the difference between the average stock price and the fair market value on November 25, 2012.
	On January 10, 2013, at the request of all holders of the Company’s Senior Unsecured Convertible Debentures, due 2018, the Company modified through a third amendment the terms of the interest payment due to the holders. Under the terms of the third amendment, the holders agreed to receive interest payments on an annual basis starting on November 25, 2013 (instead of semi-annual interest payments) and that the Company use the average daily closing price of the Common Stock 10 business days before the interest payment due date in order to determine the conversion price. All other terms and conditions of the Debentures, including interest rate and maturity date remained the same.
	On May 24, 2013, at the request of all holders of the Company’s Senior Unsecured Convertible Debentures, due 2018, the Company modified through a fourth amendment the terms of the interest payment due to the holders. Under the terms of the fourth amendment, the holders agreed to receive semi-annual interest payments on May 25th and November 25th in shares of the Company's common stock instead of cash for 2012, 2013 and 2014, provided that the Company's shares are listed on a National Securities Exchange. Under the terms of this amendment, for the May semi-annual interest payment, the Company will use the April average daily closing price of the Common Stock in order to determine the conversion price and for the November semi-annual interest payment the Company will use the October average daily closing price of the Common Stock in order to determine the conversion price. All other terms and conditions of the Debentures, including interest rate and maturity date remained the same.
	On May 25, 2013, the total interest due to the debenture holders was $582,000 and in connection with the amendment the Company issued to the debenture holders 316,462 shares of common stock at $1.84 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 a reduction of $53,511 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2013.
	On July 2, 2013, the Company declared a special dividend of one share of EuroSite Power common stock for every ten shares of American DG Energy common stock (“special dividend”). The special dividend was paid on August 15, 2013, to stockholders of record as of the close of business on July 25, 2013. In connection with this transaction, the Company issued to its stockholders an aggregate of *4,880,679 shares of EuroSite Power common stock that it owns. The EuroSite Power shares distributed pursuant to the special dividend will not be restricted securities in the hands of shareholders who are not affiliates of American DG Energy or EuroSite Power. Affiliates may sell the securities only after a 6 month holding period pursuant to the provisions of the SEC's Rule 144.
	On August 15, 2013, in connection with the special dividend, the Company modified the conversion price of the 6%, $19,400,000 debentures issued on May 23, 2011 and November 30, 2011 from $2.20 to $2.11 per share. The adjustment to the conversion price was not an automatic adjustment pursuant to the original terms of the debentures. Accordingly, the adjustment to the conversion price was accounted for as a modification under ASC 470. The modification of the convertible debt instrument resulted in an increase in the fair value of the embedded conversion option and the carrying amount of the debt instrument was reduced by approximately $649,000. This debt discount will be amortized over the remaining term of the debt. In accordance with ASC 820, the fair value of the conversion option at the date of modification was determined by utilizing a binomial lattice model with the following key assumptions:
	Company stock price	$1.64 per share
	Risk -free rate	1.43% - 1.45%
	Term	4.78 years
	Volatility	68.80%
	On November 25, 2013, the total interest due to the debenture holders was $582,000 and in connection with the amendment the Company issued to the debenture holders 377,391 shares of common stock at $1.54 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 $59,562 of non-cash interest expense, which was the difference between the average stock price and the fair market value on May 25, 2013.
	On June 14, 2013, the Company, entered into a subscription agreement with EuroSite Power Inc., or EuroSite Power, the Company's majority owned subsidiary, for $1,100,000 of EuroSite Power's 4% Senior Unsecured Convertible Notes Due 2015, or the Notes, as part of EuroSite Power's $4,000,000 aggregate principal amount private placement of the Notes. In connection with the Company's subscription for the Notes, the Company exchanged a promissory note in the principal amount of $1,100,000, originally issued on February 26, 2013, or the Notes, for a like principal amount of the Notes and received cash for any accrued but unpaid interest on the Note.
	Included among the investors subscribing for the Notes are: Bruno Meier, a director of EuroSite Power, in the amount of $250,000; Joan Giacinti, a director of EuroSite Power, 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 the Company and EuroSite Power, 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.
	The holders of the Notes, or the Holders, 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 will mature on June 14, 2015 and will accrue interest at the rate of 4% per annum payable in cash on a semi-annual basis. At a Holder's option, the Holder's Note may be converted into shares of the 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 Holders will have the following options: request payment of their principal amount and accrued interest in cash; extend the term of the Note for an additional 3 years with an automatic decrease in interest rate to 3% per annum; or exchange the Note 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. The Notes are guaranteed on a subordinated basis by the Company. 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 Company is a party to the Noteholders Agreement as both a Holder and as the guarantor of the Notes.
	The Holders are entitled to the benefits of a registration rights agreement dated June 14, 2013 by and among EuroSite Power and the Holders, 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.
	The Company guarantees, or the Guarantees, the 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 Noteholders Agreement, may proceed directly against the Company, as guarantor, to enforce the Guarantee without first proceeding against EuroSite Power. The Company, as guarantor, shall be subrogated to all rights of the Holders of the Notes against EuroSite Power in respect of any amounts paid to a Holder by the Company on account of such Note pursuant to the provisions of the Guarantee and the Noteholders Agreement; provided, however, that the Company is not entitled to enforce, or to receive any payments based upon, such right of subrogation until the principal and interest on all of the Notes is paid in full. The Guarantees are subordinate and subject in right of payment to the prior payment in full of all Senior Guarantor Indebtedness, as such term is defined in the Noteholders Agreement, of the Company. In February 2014, the Notes were exchanged for new Notes with different terms. Please see "Note 12 - Subsequent events" for further detail.
	On September 27, 2013, Anthony S. Loumidis resigned, effective September 30, 2013, from his positions as Chief Financial Officer, Secretary and Treasurer of American DG Energy Inc., or the Company, and any other positions he may have had with the Company and the Company’s majority owned subsidiary EuroSite Power Inc. Mr. Loumidis resigned in order to pursue other professional opportunities. Mr. Loumidis’s resignation was not a result of any disagreement with the Company or the Company’s Board of Directors. On September 27, 2013, Mr. Loumidis entered into a consulting agreement with the Company pursuant to which Mr. Loumidis will act as a consultant and financial advisor to the Company.
	In March 2013 the Company provided Tecogen, a related party, funds as prepayment for equipment purchases and services to be delivered or performed in 2013. The Company received a 6.0% per annum discount on deposit balances towards future purchases.
	The Company's Chief Executive Officer is the Chairman of the Board and a significant investor in GlenRose Instruments and does not receive a salary, bonus or any other compensation from GlenRose Instruments.

Fair_value_measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2013
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, 2013, the Company has classified the warrants with put and call rights as Level 3 (see “Note 6 – 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. The Company estimated that the fair value of the warrants at December 31, 2013 using this same model with the following average assumptions assigned to the varying outcomes: expected volatility of 62.1%, risk free interest rates of 1.17%, expected lives of 1.96 and no dividends. As of December 31, 2013, the financial liabilities held by the Company and measured at fair value on a recurring basis (which consist solely of the warrant liability) were $132,265. The following table summarizes the activity for the period:
		Warrant Liabilities
	Fair value at December 31, 2012	$	389,454
	Fair value adjustment at December 31, 2013	(257,189		)
	Fair value at December 31, 2013	$	132,265

Income_taxes

Income taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income taxes	'
	Income taxes:
	A reconciliation of federal statutory income tax provision to the Company’s actual provision for the years ended December 31, 2013 and 2012, respectively, are as follows:
		2013			2012
	Benefit at federal statutory tax rate	$	(1,647,000	)	$	(2,118,000	)
	Foreign rate differential	141,330			122,076
	Unbenefited operating losses	1,505,670			1,995,924
	Provision for income taxes	13,450			24,550
	Income tax provision	$	13,450		$	24,550
	The components of net deferred tax assets recognized in the accompanying balance sheets at December 31, 2013 and 2012, respectively, are as follows:
		2013			2012
	Net operating loss carryforwards	$	9,902,000		$	8,863,000
	Accrued expenses and other	200,000			142,000
	Stock compensation	1,014,000			745,000
	Depreciation	(516,000		)	(661,000		)
		10,600,000			9,089,000
	Valuation allowance	(10,600,000		)	(9,089,000		)
	Net deferred tax asset	$	—		$	—
	As of December 31, 2013, the Company has federal and state loss carryforwards of approximately $25,191,000 and $20,514,000, respectively, which may be used to offset future federal and state taxable income, expiring at various dates through 2033. 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, 2013, the Company also has foreign loss carryforwards of approximately $2,635,000 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 Company adopted accounting for uncertain tax positions effective January 1, 2007. The adoption of this statement had no effect on the Company’s financial position. The Company has no uncertain tax positions as of either the date of the adoption, or as of December 31, 2013.
	In 2013, the Company received $285,718 in grants and awards, of which $96,818 were grant awards from the US Treasury Department, or Treasury, under the 1603 Treasury program of the 2009 American Recovery and Reinvestment Act, or the Act. The Act authorizes the Treasury to make payments to eligible persons who place in service qualifying renewable energy property. The grants are paid in lieu of investment tax credits. All of the proceeds from the grants were used and recorded as a reduction in the cost basis of the applicable project assets. If the Company disposes of the property, or the property ceases to qualify as specified energy property within five years from the date the property was placed in service, then the prorated portion of the 1603 Treasury program payments must be repaid. For tax purposes, the 1603 payments are not included in federal and certain state taxable income and the basis of the property is reduced by 50% of the payment received.
	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, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and contingencies	'
	Commitments and contingencies:
	In July 2012, the Company entered into 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. The Company also shares personnel support services with Tecogen. The Company is allocated its share of the cost of the personnel support services based upon the amount of time spent by such support personnel while working on the Company’s behalf. To the extent Tecogen is able to do so under its current plans and policies, Tecogen includes the Company and its employees in several of its insurance and benefit programs. The costs of these programs are charged to the Company on an actual cost basis. Under this agreement, the Company receives pricing based on a volume discount if it purchases cogeneration and chiller products from Tecogen. For certain sites, the Company hires Tecogen to service its Tecogen chiller and cogeneration products.
	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 increases the space provided to the Company by Tecogen from approximately 3,071 square feet to 3,282 square feet and from six offices to nine offices. Under the Amendment, the amount that the Company will pay Tecogen for the space and services that Tecogen provides under the Agreement increased to $6,495 per month. The Amendment 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.
	In May 2012, the Company and an energy customer settled contractual claims without admission of liability by either party. As a result of this settlement, the equipment was removed from the site at a cost of $100,500 and the movement of the equipment resulted in an additional charge of $237,968 (included in the depreciation expense) in the second quarter of 2012. In addition, the Company, in the ordinary course of business is involved in various legal matters, the outcomes of which are not expected to have a material impact on the financial statements.

Subsequent_events

Subsequent events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent events	'
	Subsequent events:
	Note Exchange
	On February 20, 2014, a note exchange agreement, or the Note Exchange Agreement, to which the Company, is a party was accepted by EuroSite Power Inc., or EuroSite Power, the Company’s majority owned subsidiary, pursuant to which the Company exchanged its 4% Senior Convertible Note Due 2015 in an aggregate principal amount of $1,100,000, originally issued on June 14, 2013, for a 4% Senior Convertible Note Due 2017 of like principal amount, or the New Notes. The exchange took place as part of EuroSite Power’s exchange of an aggregate principal amount of $4,000,000 of its 4% Senior Convertible Notes Due 2015, or the Notes, for a like principal amount of 4% Senior Convertible Notes Due 2017, or the New Notes. Accrued but unpaid interest on the Notes will be treated as accrued interest under the New Notes.
	Included among the investors exchanging their Notes for New Notes are: Bruno Meier, a director of EuroSite Power, in the amount of $250,000; Prime World Inc., a company controlled by Joan Giacinti, a director of EuroSite Power, 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 the Company and EuroSite Power, 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.
	Noteholders Agreement
	The holders of the Notes were subject to and entitled to the benefits of the Noteholders Agreement, and such agreement was amended by the Note Exchange Agreements. The Noteholders Agreement remains in effect as to the New Notes (including with respect to Registration Rights and Guarantees), except it has been amended to reflect the maturity of the New Notes as June 14, 2017; provide that the initial conversion rate of the New Notes is 1,667 shares of common stock per $1,000 principal amount of the New Notes, subject to adjustment; and eliminate the noteholders’ options to extend the Notes.
	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_account1

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Principles of Consolidation and Basis of Presentation	'
	Principles of Consolidation and Basis of Presentation:
	The accompanying consolidated financial statements include the accounts of the Company, its wholly-owned subsidiary American DG Energy, its 51.0% joint venture, American DG New York, LLC, or ADGNY, and its 70.7% owned subsidiary EuroSite Power Inc., or EuroSite Power. The Company’s owns 51.0% of ADGNY, after elimination of all material intercompany accounts, transactions and profits. The interest in underlying energy system projects in the joint venture varies 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 and profitability of the joint venture and underlying energy projects. 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, Peter Westerhoff, each quarter. On the Company’s balance sheet, noncontrolling interest represents the partner’s investment in the entity, plus its share of after tax profits less any cash distributions. The Company owned a controlling 51.0% legal interest and a 62.5% economic interest in ADGNY as of December 31, 2013.
	In July 2010, the Company invested $45,000 in exchange for 45 million shares of EuroSite Power, a newly established corporation. The investment gave the Company a controlling financial interest in EuroSite Power, whose business focus is to introduce the On-Site Utility solution into the European market. Also in July 2010, Nettlestone Enterprises Limited, invested $5,000 in exchange for 5 million shares in EuroSite Power. In 2011, EuroSite Power raised approximately $1,250,000 in private placements by selling 1,250,000 shares of its common stock to accredited investors at $1.00 per share. In March 2012, EuroSite Power issued 851,100 shares to its existing stockholders in connection with a 10.0% stock dividend and in November 2012, EuroSite Power raised approximately $2,385,000 in a public offering and private placement by selling 2,385,000 shares of its common stock and 2,507,525 warrants, including placement agent warrants, to accredited investors at $1.00 per share.
	On July 2, 2013, the Company declared a special dividend of one share of EuroSite Power common stock for every ten shares of American DG Energy common stock (“special dividend”). The special dividend was paid on August 15, 2013, to stockholders of record as of the close of business on July 25, 2013. In connection with this transaction, the Company issued to its stockholders an aggregate of 4,880,679 shares of EuroSite Power common stock that it owns.
	As of December 31, 2013, the Company owns a 70.7% interest in EuroSite Power and has consolidated EuroSite Power into its financial statements in accordance with generally accepted accounting principles, or GAAP.
	On February 10, 2012, EuroSite Power announced that its Board of Directors declared a stock dividend of 10.0% per share on the outstanding shares of EuroSite Power common stock. The dividend was payable on March 12, 2012 to common stockholders of record at the close of business on February 24, 2012. The Company rejected the receipt of the dividend on the EuroSite Power shares it held at that time. Prior to that transaction, EuroSite Power had paid no cash or stock dividends on its common stock.
	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 revenue is generated in the United States of America and in the United Kingdom. During the years ended December 31, 2013 and 2012 revenue generated in the United States amounted to $6,623,001 and $5,564,084 respectively and revenue generated in the United Kingdom amounted to $838,879 and $81,110 respectively.  At December 31, 2013, $17,900,959 of the Company’s long lived assets were located in the United States of America and $4,030,330 were located in the United Kingdom.  At December 31, 2012, $15,726,700 of the Company’s long lived assets were located in the United States of America and $1,526,948 were located in the United Kingdom.
	The Company has experienced total net losses since inception of approximately $29.3 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 March 31, 2015, 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.
	In 2012, the Company raised $3,535,038, net of issuance costs, from common stock and convertible debt. If the Company is unable to raise additional capital in 2015 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.
	As of December 31, 2013, the Company owns a 70.7% interest in EuroSite Power and has consolidated EuroSite Power into its financial statements in accordance with generally accepted accounting principles, or GAAP.
Use of Estimates	'
	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 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 by-product of the energy business, in some cases, the customer may choose to have the Company construct the system for them 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. The Company had no such arrangements in the years ended December 31, 2013 and 2012, respectively.
	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 had no such arrangements in the years ended December 31, 2013 and 2012, respectively.
	Occasionally, the Company will enter into a sales arrangement with a customer to construct and sell an energy system and provide energy and maintenance services over the term of the contract. Based on the fact that the Company sells each deliverable to other customers on a stand-alone basis, the Company has determined that each deliverable has a stand-alone value. Additionally, there are no rights of return relative to the delivered items; therefore, each deliverable is considered a separate unit of accounting. Revenue is allocated to each element based upon its relative selling price which is determined based on the estimated price of the deliverables when sold on a standalone basis. Revenue related to the construction of the energy system is recognized using the percentage-of-completion method as the unit is being constructed. Revenue from the sale of energy is recognized when electricity, heat, and chilled water is produced by the energy system, and revenue from maintenance services is recognized over the term of the maintenance agreement. The Company had no such arrangements at December 31, 2013 and 2012, respectively.
	The Company is able to participate in the demand response market and receive payments due to the availability of its energy systems. Demand response programs provide 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 year ended December 31, 2013 and 2012, the revenue recognized from demand response activity was $112,405 and $106,340, respectively. The Company treats demand response payments as an operating activity in the statements of cash flows.
	Other revenue represents various types of ancillary activities for which the Company engages from time to time such as the sale of equipment, and feasibility studies.
Cash and Cash Equivalents	'
	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	'
	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, 2013, the Company had a balance of $8,554,191 in cash and cash equivalents that exceeded the Federal Deposit Insurance Corporation limit.
Accounts Receivable	'
	Accounts Receivable
	The Company maintains receivable balances primarily with customers located throughout New York and New Jersey. 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 when identified.
	At December 31, 2013 and 2012, the allowance for doubtful accounts was $183,201 and $54,000, respectively. Included in accounts receivable are amounts from four major customers accounting for approximately 35.0% and 29.0% of total accounts receivable for the years ended December 31, 2013 and 2012, respectively. There were sales to four major customers accounting for approximately 25.0% and 32.0% of total sales for the years ended December 31, 2013 and 2012, respectively.
Inventory	'
	Inventory
	Inventories 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, 2013 and 2012, there were no reserves or write-downs recorded against inventory.
Supply Concentrations	'
	Supply Concentrations
	All of the Company’s cogeneration unit purchases for the years ended December 31, 2013 and 2012 were from one vendor (see “Note 8 - 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. 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 and Depreciation and Amortization	'
	Property and Equipment and Depreciation and Amortization
	Property 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 the useful life of its energy systems on a quarterly basis or 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 impairment is indicated by comparing the 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 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.
	The Company receives rebates and incentives from various utility companies 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 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
	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 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 5 – 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, 2013 and 2012, respectively.
Loss per Common Share	'
	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, 2013, the Company excluded 12,088,313 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, 2012, the Company excluded 11,445,182 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.
	Other Comprehensive Net Loss
	The comprehensive net loss for the years ended December 31, 2013 and 2012 does not differ
Other Comprehensive Net Loss	'
	Other Comprehensive Net Loss
	The comprehensive net loss for the years ended December 31, 2013 and 2012 does not differ from the reported loss.
Income Taxes	'
	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. In addition, the Company is required to provide a tabular reconciliation of the change in the aggregate unrecognized tax benefits claimed, or expected to be claimed, in tax returns and disclosure relating to the accrued interest and penalties for unrecognized tax benefits. Discussion is also required for those uncertain tax positions where it is reasonably possible that the estimate of the tax benefit will change significantly in the next twelve months.
	The tax years 2003 through 2005 and 2010 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	'
	Fair Value of Financial Instruments
	The Company’s financial instruments are cash and cash equivalents, short-term investments, accounts receivable, 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 warrant liability is recorded at fair value. The carrying value of the convertible debentures on the balance sheet at December 31, 2013 approximates fair value as the terms approximate those currently available for similar instruments. See “Note 9 - Fair value measurements.”
Impact of New Accounting Pronouncements	'
	Impact of New Accounting Pronouncements
	The Company does not expect the impact of recently issued accounting pronouncements to have a material impact on the Company's results of operation, financial position, or cash flows.

Property_plant_and_equipment_T

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Property, Plant and Equipment	'
	Property, plant and equipment consist of the following as of December 31, 2013 and 2012, respectively:
		2013			2012
	Energy Systems	$	25,567,808		$	19,052,933
	Computer equipment and software	122,853			109,910
	Furniture and fixtures	85,079			81,435
	Vehicles	243,139			166,193
		26,018,879			19,410,471
	Less — accumulated depreciation	(7,621,242		)	(6,149,328		)
		18,397,637			13,261,143
	Construction in progress	3,533,652			3,992,505
		$	21,931,289		$	17,253,648

Convertible_debentures_Tables

Convertible debentures (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Fair Value Measurements Assumptions	'
	This debt discount will be amortized over the remaining term of the debt. In accordance with ASC 820, the fair value of the conversion option at the date of modification was determined by utilizing a binomial lattice model with the following key assumptions:
	Company stock price	$1.64 per share
	Risk -free rate	1.43% - 1.45%
	Term	4.78 years
	Volatility	68.80%
	This debt discount will be amortized over the remaining term of the debt. In accordance with ASC 820, the fair value of the conversion option at the date of modification was determined by utilizing a binomial lattice model with the following key assumptions:
	Company stock price	$1.64 per share
	Risk -free rate	1.43% - 1.45%
	Term	4.78 years
	Volatility	68.80%

Stockholders_equity_Tables

Stockholders' equity (Tables)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Schedule Of Warrants Activity	'
	Warrant activity for the years ended December 31, 2013 and 2012 was as follows:
		Number of			Weighted Average
		Warrants			Grant Date
					Fair Value
	Unvested, December 31, 2011	588,000			$	3.12
	Granted	50,000			0.15
	Exercised	—			—
	Expired	(72,500	)		0.58
	Unvested, December 31, 2012	565,500			$	3.19
	Granted	—			—
	Exercised	—			—
	Expired	84,500			0.17
	Unvested, December 31, 2013	507,500			$	3.24
Summary of Fair Value Stock Option Assumptions	'
	The weighted average assumptions used in the Black-Scholes option pricing model are as follows:
		2013			2012
	Stock options and restricted stock awards
	Expected life	5 years			5 years
	Risk-free interest rate	1.75	%		0.74	%
	Expected volatility	60.3	%		72.8	%
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 years ended December 31, 2013 and 2012 was as follows:
	Common Stock Options	Number of Options		Weighted Average Exercise Price			Weighted Average Remaining Life	Aggregate Intrinsic Value
	Outstanding, December 31, 2011	2,008,375		$	1.15		4.87 years	$	1,055,319
	Granted	342,000		2.39
	Exercised	(277,625	)	0.72
	Canceled	(11,250	)	2.64
	Expired	—		—
	Outstanding, December 31, 2012	2,061,500		$	1.4		4.32 years	$	2,151,585
	Exercisable, December 31, 2012	1,047,250		$	1.09			$	1,366,918
	Vested and expected to vest, December 31, 2012	2,061,500		$	1.4			$	2,151,585
	Outstanding, December 31, 2012	2,061,500		$	1.4		4.32 years	$	2,151,585
	Granted	430,000		1.59
	Exercised	—		—
	Canceled	(5,000	)	1.4
	Expired	(100,000	)	0.07
	Outstanding, December 31, 2013	2,386,500		$	1.49		4.13 years	$	1,092,550
	Exercisable, December 31, 2013	1,241,750		$	1.36			$	753,550
	Vested and expected to vest, December 31, 2013	2,386,500		$	1.49			$	1,092,550
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 years ended December 31, 2013 and 2012 was as follows:
	Common Stock Options	Number of Options		Weighted Average Exercise Price			Weighted Average Remaining Life		Aggregate Intrinsic Value
	Outstanding, December 31, 2011	3,600,000		$	0.9		9.34 years		$	—
	Granted	—		—
	Exercised	—		—
	Canceled	(10,000	)	0.9
	Expired	—		—
	Outstanding, December 31, 2012	3,590,000		$	0.9		8.34 years		$	359,000
	Exercisable, December 31, 2012	897,500		$	0.9				$	89,750
	Vested and expected to vest, December 31, 2012	3,590,000		$	0.9				$	359,000
	Outstanding, December 31, 2012	3,590,000		$	0.9		8.34 years		$	359,000
	Granted	438,000		0.67
	Exercised	—		—
	Canceled	(3,000	)	0.9
	Expired	—		—			—		—
	Outstanding, December 31, 2013	4,025,000		$	0.87		7.58 years		$	74,000
	Exercisable, December 31, 2013	1,795,000		$	0.9				$	—
	Vested and expected to vest, December 31, 2013	4,025,000		$	0.87				$	74,000

Related_parties_Tables

Related parties (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Fair Value Measurements Assumptions	'
	This debt discount will be amortized over the remaining term of the debt. In accordance with ASC 820, the fair value of the conversion option at the date of modification was determined by utilizing a binomial lattice model with the following key assumptions:
	Company stock price	$1.64 per share
	Risk -free rate	1.43% - 1.45%
	Term	4.78 years
	Volatility	68.80%
	This debt discount will be amortized over the remaining term of the debt. In accordance with ASC 820, the fair value of the conversion option at the date of modification was determined by utilizing a binomial lattice model with the following key assumptions:
	Company stock price	$1.64 per share
	Risk -free rate	1.43% - 1.45%
	Term	4.78 years
	Volatility	68.80%

Fair_value_measurements_Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Schedule Of Warrant Liabilities [Abstract]	'
Schedule Of Warrant Liabilities	'
	The following table summarizes the activity for the period:
		Warrant Liabilities
	Fair value at December 31, 2012	$	389,454
	Fair value adjustment at December 31, 2013	(257,189		)
	Fair value at December 31, 2013	$	132,265

Income_taxes_Tables

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Reconciliation of Federal Statutory Income Tax Provision to Company's Actual Provision	'
	A reconciliation of federal statutory income tax provision to the Company’s actual provision for the years ended December 31, 2013 and 2012, respectively, are as follows:
		2013			2012
	Benefit at federal statutory tax rate	$	(1,647,000	)	$	(2,118,000	)
	Foreign rate differential	141,330			122,076
	Unbenefited operating losses	1,505,670			1,995,924
	Provision for income taxes	13,450			24,550
	Income tax provision	$	13,450		$	24,550
Schedule of Deferred Tax Assets	'
	The components of net deferred tax assets recognized in the accompanying balance sheets at December 31, 2013 and 2012, respectively, are as follows:
		2013			2012
	Net operating loss carryforwards	$	9,902,000		$	8,863,000
	Accrued expenses and other	200,000			142,000
	Stock compensation	1,014,000			745,000
	Depreciation	(516,000		)	(661,000		)
		10,600,000			9,089,000
	Valuation allowance	(10,600,000		)	(9,089,000		)
	Net deferred tax asset	$	—		$	—

The_Company_Details

The Company (Details)	12 Months Ended
	Dec. 31, 2013
Schedule of Energy Operations [Line Items]	'
Number Of Energy Systems Installed	109
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

Summary_of_significant_account2

Summary of significant accounting policies (Details) (USD $)

0 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

Jul. 02, 2013

Dec. 09, 2010

Dec. 31, 2013

Dec. 31, 2012

Jul. 31, 2010

Nov. 30, 2012

Mar. 31, 2012

Jul. 31, 2010

Dec. 31, 2012

Dec. 31, 2013

Feb. 10, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

segment

Nettlestone Enterprises Limited

Eurosite Power Inc

Eurosite Power Inc

Eurosite Power Inc

Eurosite Power Inc

Eurosite Power Inc

Eurosite Power Inc

American DG New York, LLC

UNITED STATES

UNITED STATES

UNITED KINGDOM

UNITED KINGDOM

Subsidary or Equity Method Investee [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage Of Ownership In Joint Venture

'

'

'

'

'

'

'

'

'

'

'

51.00%

'

'

'

'

Percentage Of Ownership In Subsidiary

'

'

'

'

'

'

'

'

'

70.70%

'

'

'

'

'

'

Percentage Of Economic Interest

'

'

62.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash paid in exhange for shares of EuroSite Power

'

'

'

'

$5,000

'

'

$45,000

'

'

'

'

'

'

'

'

Shares of EuroSite Power received in the exchange (shares)

'

'

'

'

5,000,000

'

'

45,000,000

'

'

'

'

'

'

'

'

Proceeds received from sale of stock in private placement

'

'

'

'

'

'

'

'

1,250,000

'

'

'

'

'

'

'

Number of shares sold in private placement (shares)

'

'

'

'

'

2,385,000

'

'

1,250,000

'

'

'

'

'

'

'

Common stock, price per share (usd per share)

'

'

'

'

'

$1

'

'

$1

'

'

'

'

'

'

'

Stock Issued During Period, Shares, New Issues

'

'

'

'

'

'

851,100

'

'

'

'

'

'

'

'

'

Warrants Issued During Period

'

500,000

'

'

'

2,507,525

'

'

'

'

'

'

'

'

'

'

Stock dividend per share, declared (usd per share)

'

'

'

'

'

'

10.00%

'

'

'

10.00%

'

'

'

'

'

Proceeds from issuance or sale of equity

'

'

'

'

'

2,385,000

'

'

'

'

'

'

'

'

'

'

Stock Issued During Period, Shares, Other

4,881,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Operating Segments

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue, Net

'

'

7,461,880

5,645,194

'

'

'

'

'

'

'

'

6,623,001

5,564,084

838,879

81,110

Long-Lived Assets

'

'

'

'

'

'

'

'

'

'

'

'

$17,900,959

$15,726,700

$4,030,330

$1,526,948

Summary_of_significant_account3

Summary of significant accounting policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]	'	'
Net losses since inception	($29,343,517)	($24,456,845)
Revenue recognized from demand response activity	112,405	106,340
Maximum maturity period for highly liquid investments	'3 months	'
Proceeds from Issuance of Private Placement	'	3,535,038
Cash and Cash Equivalents concentration risk	$8,554,191	'
Antidilutive shares excluded from computation of loss per share (shares)	12,088,313	11,445,182
Sales Revenue, Net [Member]	'	'
Concentration Risk [Line Items]	'	'
Percentage of concentration	12.00%	15.00%

Summary_of_significant_account4

Summary of significant accounting policies (Accounts Receivable and Payble) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
	customer	customer
Concentration Risk [Line Items]	'	'
Allowance for Doubtful Accounts Receivable	183,201	54,000
Customer Concentration Risk | Accounts Receivable	'	'
Concentration Risk [Line Items]	'	'
Number Of Major Customers	4	4
Percentage of concentration	35.00%	29.00%
Customer Concentration Risk | Sales	'	'
Concentration Risk [Line Items]	'	'
Number Of Major Customers	4	4
Percentage of concentration	25.00%	32.00%

Summary_of_significant_account5

Summary of significant accounting policies (Accounts Payable and Supply Concentrations) (Details) (Supplier Concentration Risk)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
	vendor	vendor
Concentration Risk [Line Items]	'	'
Number of Major Vendors	1	1
Accounts Payable	'	'
Concentration Risk [Line Items]	'	'
Number of Major Vendors	4	4
Percentage of concentration	30.00%	34.00%
Purchases	'	'
Concentration Risk [Line Items]	'	'
Number of Major Vendors	4	4
Percentage of concentration	35.00%	47.00%

Summary_of_significant_account6

Summary of significant accounting policies (Property and Equipment) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]	'	'
Amount of grant awards received under The American Recovery And Reinvestment Act	$285,718	'
Rebates applied to cost of construction	'	$583,800
Minimum	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Useful Life	'12 years	'
Maximum	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, Plant and Equipment, Useful Life	'15 years	'

Property_plant_and_equipment_S

Property, plant and equipment (Summary of Property, Plant and Equipment) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	$26,018,879	$19,410,471
Less ----- accumulated depreciation	-7,621,242	-6,149,328
Property, plant and equipment, before contruction in progress	18,397,637	13,261,143
Construction in progress	3,533,652	3,992,505
Property, plant and equipment, net	21,931,289	17,253,648
Energy Systems	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	25,567,808	19,052,933
Computer equipment and software	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	122,853	109,910
Furniture and fixtures	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	85,079	81,435
Vehicles	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	$243,139	$166,193

Property_plant_and_equipment_D

Property, plant and equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]	'	'
Depreciation expense	$1,471,914	$1,754,279

Convertible_debentures_Details

Convertible debentures (Details) (USD $)

0 Months Ended

1 Months Ended

9 Months Ended

Nov. 25, 2013

Aug. 15, 2013

Jul. 02, 2013

25-May-13

Jan. 10, 2013

Nov. 25, 2012

Sep. 28, 2012

25-May-12

Nov. 30, 2011

Aug. 15, 2011

23-May-11

Nov. 30, 2011

23-May-11

Sep. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Debt Disclosure [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Repurchased Face Amount

'

$649,000

'

'

'

'

'

'

'

'

'

'

'

$649,000

'

'

Long-term Debt

'

'

'

'

'

'

'

'

'

'

12,500,000

'

12,500,000

'

'

'

Debt Instrument, Maturity Date

'

'

'

'

'

'

'

'

25-May-18

'

25-May-18

25-May-18

25-May-18

'

'

'

Due to related party

'

'

'

'

'

'

'

'

6,900,000

'

'

6,900,000

'

'

178,216

41,812

Debt Instrument, Convertible, Effective Interest Rate

'

'

'

'

'

'

'

'

6.00%

'

6.00%

'

6.00%

'

'

'

Long-term Debt, Gross

'

19,400,000

'

'

'

'

'

'

'

19,400,000

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Price, Prior (in dollars per share)

'

$2.20

'

'

'

'

'

'

'

$2.20

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Price (in dollars per share)

'

$2.11

'

'

'

'

'

'

$2.20

$2.11

$2.20

$2.20

$2.20

'

'

'

Percentage Of Option To Redeem Par Value

'

'

'

'

'

'

'

'

115.00%

'

115.00%

'

115.00%

'

'

'

Line of Credit Facility, Amount Outstanding

'

'

'

'

'

'

'

'

'

'

2,400,000

'

2,400,000

'

'

'

Debt Instrument, Periodic Payment, Interest

582,000

'

'

582,000

'

582,000

'

559,000

'

'

'

'

'

20,000

'

'

Common stock, shares issued

377,391

'

'

316,462

'

249,787

'

251,917

'

'

'

'

'

'

49,817,920

48,490,733

Common stock, par value (usd per share)

$1.54

'

'

$1.84

'

$2.33

'

$2.22

'

'

'

'

'

'

$0.00

$0.00

Non-cash interest (interest) expense, adjusted for the difference between the average stock price and the fair market value

'

'

'

53,511

'

'

'

153,921

'

'

'

'

'

'

'

'

Number of business days used to determine the average daily closing price of the Company's common stock

'

'

'

'

'10 days

'

'10 days

'

'

'

'

'

'

'

'

'

Reduction in non-cash interest expense adjusted for the difference between the average stock price and the fair market value

$59,562

'

'

'

'

($57,451)

'

'

'

'

'

'

'

'

'

'

Stock Issued During Period, Shares, Other

'

'

4,881,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockholders' Equity Note, Stock Split, Holding Period

'

'

'6 months

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Ratio

'

0.06

'

'

'

'

'

'

'

0.06

'

'

'

'

'

'

Convertible_debentures_Fair_va

Convertible debentures (Fair value assumptions) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Sep. 04, 2013	Aug. 28, 2013	Aug. 07, 2012	Mar. 27, 2012
Debt Instrument [Line Items]	'	'	'	'	'
Company stock price	$1.64	$1.50	$1.55	$1.60	$1.60
Term	'4 years 9 months 10 days	'	'	'	'
Volatility	68.80%	'	'	'	'
Minimum	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Risk -free rate	1.43%	'	'	'	'
Maximum	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Risk -free rate	1.45%	'	'	'	'

Convertible_debentures_Eurosit

Convertible debentures (Eurosite Power Convertible Debenture) (Details) (USD $)

Jun. 14, 2013

Dec. 31, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Sep. 30, 2013

Dec. 31, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Unsecured Debt

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

Prepayment from Related Party for Future Purchases [Member]

Prepayment from Related Party for Future Purchases [Member]

Bruno Meier

Joan Giacinti

Charles T. Maxwell

Nettlestone Enterprises Limited

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Unsecured Debt

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

Convertible Debt

EuroSite Power

EuroSite Power

Bruno Meier

Bruno Meier

Joan Giacinti

Joan Giacinti

Charles T. Maxwell

Charles T. Maxwell

Nettlestone Enterprises Limited

Nettlestone Enterprises Limited

Perastra Management Management S.A

Yves Micheli

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Convertible Debt

Senior Convertible Notes Due 2017

EuroSite Power

Senior Convertible Notes Due 2017

EuroSite Power

Senior Convertible Notes Due 2017

EuroSite Power

Senior Convertible Notes Due 2017

EuroSite Power

EuroSite Power

EuroSite Power

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Maximum Borrowing Capacity

'

$1,100,000

'

$1,100,000

'

'

'

$250,000

$300,000

$250,000

$300,000

'

$1,100,000

'

$250,000

$250,000

$300,000

$300,000

$250,000

$250,000

$300,000

$300,000

$1,500,000

$300,000

Related Party Transaction, Discount Rate

'

'

'

'

'

6.00%

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Face Amount

'

'

'

'

4,000,000

'

'

'

'

'

'

4,000,000

'

4,000,000

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

4.00%

'

'

6.00%

4.00%

'

'

'

'

'

'

4.00%

'

4.00%

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Shares

'

'

'

'

1,000

'

'

'

'

'

'

1,667

'

1,667

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Extension Period

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Increase (Decrease)

'

'

'

'

-3.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Term

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Registration Rights Percentage

'

'

30.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Registration Rights, Offering Price, Net

'

'

$250,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockholders_equity_Details

Stockholders' equity (Details) (USD $)

0 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Sep. 04, 2013

Aug. 28, 2013

Aug. 07, 2012

Mar. 27, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 09, 2010

Dec. 31, 2013

Dec. 31, 2013

Feb. 22, 2012

Dec. 31, 2013

Dec. 31, 2013

Jan. 15, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jun. 13, 2011

Jun. 11, 2011

Oct. 15, 2013

Mar. 20, 2013

Oct. 15, 2013

Mar. 20, 2013

Dec. 31, 2013

Dec. 31, 2012

Aug. 28, 2013

Mar. 20, 2013

Mar. 20, 2013

Mar. 20, 2013

Oct. 15, 2013

Dec. 31, 2013

Dec. 31, 2013

Minimum

Maximum

22-Feb-13

14-Dec-15

15-Jan-16

15-Jan-16

American DG Energy

American DG Energy

American DG Energy

American DG Energy

American DG Energy

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

Director

Director

Charles T. Maxwell

Employee [Member]

Director

Consultant [Member]

Executive Officer [Member]

Expire in Five Years [Member]

Expire in Ten Years [Member]

employee

employee

Stock Options

Minimum

Stock Compensation Plan

Stock Compensation Plan

Minimum

Minimum

Maximum

Maximum

American DG Energy

American DG Energy

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

American DG Energy

American DG Energy

Stock Options

employee

Stock Options

Stock Options

Class of Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds From Sale Of Restricted Common Stock

$500,001

$465,000

$2,000,000

$1,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued During Period Shares Restricted Stock

333,334

'

1,250,000

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

300,000

'

'

'

'

'

'

Company stock price

$1.50

$1.55

$1.60

$1.60

$1.64

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.00

'

'

'

'

'

'

Common stock, shares outstanding

'

'

'

'

49,817,920

48,490,733

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments for Repurchase of Common Stock

'

'

'

'

0

750,000

'

'

'

'

7,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants Exercised Expire Date

'

'

'

'

'

'

'

'

'

'

22-Feb-13

14-Dec-15

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Warrants Granted (in shares)

'

'

'

'

0

50,000

'

'

'

'

50,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants, Exercise Price Per Share

'

'

'

'

'

'

'

$3.25

'

'

$3

$3.25

'

$2.69

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Warrants Outstanding (in shares)

'

'

'

'

507,500

565,500

588,000

'

'

'

'

500,000

7,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Shares Authorized

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

'

'

'

'

'

4,500,000

3,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital Shares Reserved for Future Issuance

'

'

'

'

'

'

'

'

'

'

'

'

'

'

105,500

'

'

'

'

475,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation

'

'

'

'

596,349

810,285

'

'

'

'

'

'

'

'

596,349

810,285

'

'

'

238,404

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Compensation Cost Not yet Recognized

'

'

'

'

740,221

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years 11 months 9 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Non-qualified Options Issued in Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

350,000

42,000

'

'

'

'

'

'

'

'

'

'

'

'

80,000

300,000

'

'

'

'

'

150,000

280,000

Number Of Individuals

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

5

'

'

'

'

'

'

'

'

'

'

'

'

1

2

'

'

'

'

'

'

'

Exercise price per share Granted Lower Range (usd per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.54

$1.60

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price per share Granted Upper Range (usd per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.67

$2.79

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vesting Period

'

'

'

'

'

'

'

'

'2 years

'10 years

'

'

'

'

'

'

'

'

'4 years

'4 years

'

'

'

'

'4 years

'4 years

'10 years

'10 years

'

'

'

'

'

'

'

'

'

Share Based Compensation Arrangement By Share Based Payment Award Options Canceled In Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-5,000

-11,250

'

'

'

-3,000

-10,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Options Expired (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-100,000

0

'

'

'

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expiration Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'10 years

Options Issued, Fair Value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

368,044

456,392

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Granted in Period, Weighted Average Grant Date Fair Value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.86

$1.33

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Options Granted (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

430,000

342,000

'

'

'

438,000

0

'

'

'

'

'

'

'

'

'

'

88,000

100,000

50,000

200,000

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Options, Number of Employees Granted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6

'

'

'

'

'

Weighted Average Exercise Price Granted (usd per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1.59

$2.39

'

'

'

$0.67

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Remaining Life Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years 1 month 17 days

'4 years 3 months 26 days

'4 years 10 months 13 days

'

'

'7 years 6 months 29 days

'8 years 3 months 34 days

'9 years 4 months 2 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value Assumptions Risk Free Interest Rate

'

'

'

'

1.75%

0.74%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected volatility

'

'

'

'

60.30%

72.80%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Options Outstanding (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,386,500

2,061,500

2,008,375

'

'

4,025,000

3,590,000

3,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Compensation Cost Not yet Recognized, Stock Options

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$220,936

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockholders_equity_Class_of_R

Stockholders' equity Class of Rights and Warrants (Details) (USD $)	12 Months Ended				0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 09, 2010	Feb. 22, 2012	Dec. 31, 2013	Dec. 31, 2013	Jan. 15, 2011
					22-Feb-13	14-Dec-15	15-Jan-16	15-Jan-16
Class of Warrant or Right [Line Items]	'	'	'	'	'	'	'	'
Number of Warrants Granted (in shares)	0	50,000	'	'	50,000	'	'	'
Warrants, Exercise Price Per Share	'	'	'	$3.25	$3	$3.25	'	$2.69
Number of Warrants Outstanding (in shares)	507,500	565,500	588,000	'	'	500,000	7,500	'
Warrants Exercised Expire Date	'	'	'	'	22-Feb-13	14-Dec-15	'	'
Payments for Repurchase of Common Stock	$0	$750,000	'	'	$7,500	'	'	'

Stockholders_equity_Summary_of

Stockholders' equity (Summary of Warranty Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Number of Warrants Outstanding [Roll Forward]	'	'
Number of Warrants Outstanding, Beginning (in shares)	565,500	588,000
Number of Warrants Granted (in shares)	0	50,000
Number of Warrants Exercised (in shares)	0	0
Number of Warrants Expired (in shares)	-84,500	-72,500
Number of Warrants Outstanding, Ending (in shares)	507,500	565,500
Weighted Average Grant Date Fair Value [Roll Forward]	'	'
Weighted Average Grant Date Fair Value Outstanding, Beginning (usd per share)	$3.19	$3.12
Weighted Average Grant Date Fair Value Granted (usd per share)	$0	$0.15
Weighted Average Grant Date Fair Value Exercised (usd per share)	$0	$0
Weighted Average Grant Date Fair Value Expired (usd per share)	$0.17	$0.58
Weighted Average Grant Date Fair Value Outstanding, Ending (usd per share)	$3.24	$3.19

Stockholders_equity_Summary_of1

Stockholders' equity (Summary of Weighted Average Assumptions Used In Black Scholes Option Pricing Model) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]	'	'
Expected life	'5 years	'5 years
Risk-free interest rate	1.75%	0.74%
Expected volatility	60.30%	72.80%

Stockholders_equity_Summary_of2

Stockholders' equity (Summary of Stock Option Activity) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
American DG Energy	'	'	'
Stock Options, Outstanding [Roll Forward]	'	'	'
Number of Options Outstanding Beginning (in shares)	2,061,500	2,008,375	'
Number of Options Granted (in shares)	430,000	342,000	'
Number of Options Exercised (in shares)	0	-277,625	'
Number of Options Canceled (in shares)	-5,000	-11,250	'
Number of Options Expired (in shares)	100,000	0	'
Number of Options Outstanding, Ending (in shares)	2,386,500	2,061,500	2,008,375
Number of Option Exercisable, December 31, 2013 (in shares)	1,241,750	1,047,250	'
Number of Option Vested and expected to vest, December 31, 2013 (in shares)	2,386,500	2,061,500	'
Weighted Average Exercise Price [Roll Forward]	'	'	'
Weighted Average Exercise Price Outstanding, Beginning (usd per share)	$1.40	$1.15	'
Weighted Average Exercise Price Granted (usd per share)	$1.59	$2.39	'
Weighted Average Exercise Price Exercised (usd per share)	$0	$0.72	'
Weighted Average Exercise Price Cancelled (usd per share)	$1.40	$2.64	'
Weighted Average Exercise Price Expired (usd per share)	$0.07	$0	'
Weighted Average Exercise Price Outstanding, Ending (usd per share)	$1.49	$1.40	$1.15
Weighted Average Exercise Price Exercisable, December 31, 2013 (usd per share)	$1.36	$1.09	'
Weighted Average Exercise Price Vested and expected to vest, December 31, 2013 (usd per share)	$1.49	$1.40	'
Options, Additional Disclosures [Abstract]	'	'	'
Weighted Average Remaining Life Outstanding, Beginning	'4 years 1 month 17 days	'4 years 3 months 26 days	'4 years 10 months 13 days
Weighted Average Remaining Life Outstanding, Ending	'4 years 1 month 17 days	'4 years 3 months 26 days	'4 years 10 months 13 days
Aggregate Intrinsic Value Outstanding, Beginning	$2,151,585	$1,055,319	'
Aggregate Intrinsic Value Outstanding, Ending	1,092,550	2,151,585	1,055,319
Aggregate intrinsic value Exercisable	753,550	1,366,918	'
Aggregate Intrinsic value Vested and expected to vest	1,092,550	2,151,585	'
EuroSite Power	'	'	'
Stock Options, Outstanding [Roll Forward]	'	'	'
Number of Options Outstanding Beginning (in shares)	3,590,000	3,600,000	'
Number of Options Granted (in shares)	438,000	0	'
Number of Options Exercised (in shares)	0	0	'
Number of Options Canceled (in shares)	-3,000	-10,000	'
Number of Options Expired (in shares)	0	0	'
Number of Options Outstanding, Ending (in shares)	4,025,000	3,590,000	3,600,000
Number of Option Exercisable, December 31, 2013 (in shares)	1,795,000	897,500	'
Number of Option Vested and expected to vest, December 31, 2013 (in shares)	4,025,000	3,590,000	'
Weighted Average Exercise Price [Roll Forward]	'	'	'
Weighted Average Exercise Price Outstanding, Beginning (usd per share)	$0.90	$0.90	'
Weighted Average Exercise Price Granted (usd per share)	$0.67	$0	'
Weighted Average Exercise Price Exercised (usd per share)	$0	$0	'
Weighted Average Exercise Price Cancelled (usd per share)	$0.90	$0.90	'
Weighted Average Exercise Price Expired (usd per share)	$0	$0	'
Weighted Average Exercise Price Outstanding, Ending (usd per share)	$0.87	$0.90	$0.90
Weighted Average Exercise Price Exercisable, December 31, 2013 (usd per share)	$0.90	$0.90	'
Weighted Average Exercise Price Vested and expected to vest, December 31, 2013 (usd per share)	$0.87	$0.90	'
Options, Additional Disclosures [Abstract]	'	'	'
Weighted Average Remaining Life Outstanding, Beginning	'7 years 6 months 29 days	'8 years 3 months 34 days	'9 years 4 months 2 days
Weighted Average Remaining Life Outstanding, Ending	'7 years 6 months 29 days	'8 years 3 months 34 days	'9 years 4 months 2 days
Aggregate Intrinsic Value Outstanding, Beginning	359,000	0	'
Aggregate Intrinsic Value Outstanding, Ending	74,000	359,000	0
Aggregate intrinsic value Exercisable	0	89,750	'
Aggregate Intrinsic value Vested and expected to vest	$74,000	$359,000	'

Warrant_liability_Details

Warrant liability (Details) (USD $)	0 Months Ended	12 Months Ended
	Dec. 09, 2010	Dec. 31, 2013
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	14-Dec-15	'
Expected Volitility, Maximum Rate	'	70.00%

Employee_benefit_plan_Details

Employee benefit plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]	'	'
Maximum employer annual contribution per employee, percent	4.50%	'
Company contributions to the plan during the year, dollars	$53,697	$56,034

Related_parties_Details

Related parties (Details) (USD $)

0 Months Ended

1 Months Ended

9 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

9 Months Ended

12 Months Ended

Nov. 25, 2013

Aug. 15, 2013

Jul. 02, 2013

25-May-13

Jan. 10, 2013

Nov. 25, 2012

Sep. 28, 2012

25-May-12

Nov. 30, 2011

Aug. 15, 2011

23-May-11

Jul. 31, 2012

Nov. 30, 2011

23-May-11

Sep. 30, 2013

Dec. 31, 2013

Jun. 30, 2013

Dec. 31, 2012

Jan. 31, 2006

Dec. 31, 2013

Oct. 23, 2009

Dec. 31, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Sep. 30, 2013

Dec. 31, 2013

office

Tecogen

Tecogen

Ilois

EuroSite Power

EuroSite Power

EuroSite Power

Unsecured Debt

Unsecured Debt

Nettlestone Enterprises Limited

Charles T. Maxwell

Joan Giacinti

Bruno Meier

Prepayment from Related Party for Future Purchases [Member]

Prepayment from Related Party for Future Purchases [Member]

sqft

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sublease Agreement Expires Date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

31-Mar-14

'

'

'

'

'

'

'

'

'

'

'

'

Related Party Transactions Agreement Term

'

'

'

'

'

'

'

'

'

'

'

'1 year

'

'

'

'

'

'

'1 year

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

Rental Income Related Party

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$6,495

'

'

'

$6,495

'

'

'

'

'

'

'

'

'

'

'

'

Commissions from related party, sale of equipmentr

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

Related Party Agreement, Original Square Feet

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,071

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Related Party Agreement, Square Feet

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,282

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Related Party Agreement, Original Number of Offices

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Related Party Agreement, Number of Offices

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Related Party Agreement, Period for Notice Termination

'

'

'

'

'

'

'

'

'

'

'

'60 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Amount Outstanding

'

'

'

'

'

'

'

'

'

'

2,400,000

'

'

2,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt

'

'

'

'

'

'

'

'

'

'

12,500,000

'

'

12,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Maturity Date

'

'

'

'

'

'

'

'

25-May-18

'

25-May-18

'

25-May-18

25-May-18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Effective Interest Rate

'

'

'

'

'

'

'

'

6.00%

'

6.00%

'

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Price

'

$2.11

'

'

'

'

'

'

$2.20

$2.11

$2.20

'

$2.20

$2.20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage Of Option To Redeem Par Value

'

'

'

'

'

'

'

'

115.00%

'

115.00%

'

'

115.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Due to related party

'

'

'

'

'

'

'

'

6,900,000

'

'

'

6,900,000

'

'

178,216

'

41,812

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Periodic Payment, Interest

582,000

'

'

582,000

'

582,000

'

559,000

'

'

'

'

'

'

20,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Repurchased Face Amount

'

649,000

'

'

'

'

'

'

'

'

'

'

'

'

649,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, shares issued

377,391

'

'

316,462

'

249,787

'

251,917

'

'

'

'

'

'

'

49,817,920

'

48,490,733

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, par value (usd per share)

$1.54

'

'

$1.84

'

$2.33

'

$2.22

'

'

'

'

'

'

'

$0.00

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Non-cash interest expense, adjusted for the difference between the average stock price and the fair market value

'

'

'

53,511

'

'

'

153,921

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of business days used to determine the average daily closing price of the Company's common stock

'

'

'

'

'10 days

'

'10 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reduction in non-cash interest expense adjusted for the difference between the average stock price and the fair market value

59,562

'

'

'

'

-57,451

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock Issued During Period, Shares, Other

'

'

4,881,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockholders' Equity Note, Stock Split, Holding Period

'

'

'6 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Ratio

'

0.06

'

'

'

'

'

'

'

0.06

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Gross

'

19,400,000

'

'

'

'

'

'

'

19,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Price, Prior (in dollars per share)

'

$2.20

'

'

'

'

'

'

'

$2.20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Maximum Borrowing Capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000

'

1,100,000

'

'

300,000

250,000

300,000

250,000

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

4.00%

4.00%

'

'

'

'

'

'

Debt Instrument, Face Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,000,000

'

'

'

'

'

'

Debt Instrument, Convertible, Shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000

'

'

'

'

'

'

Debt Instrument, Extension Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

Debt Instrument, Interest Rate, Increase (Decrease)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-3.00%

'

'

'

'

'

'

Debt Instrument, Term

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

Registration Rights Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30.00%

'

'

'

'

'

'

'

'

'

Registration Rights, Offering Price, Net

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$250,000

'

'

'

'

'

'

'

'

'

Related Party Transaction, Discount Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6.00%

6.00%

Related_parties_Fair_value_ass

Related parties (Fair value assumptions) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Sep. 04, 2013	Aug. 28, 2013	Aug. 07, 2012	Mar. 27, 2012
Debt Instrument [Line Items]	'	'	'	'	'
Company stock price	$1.64	$1.50	$1.55	$1.60	$1.60
Term	'4 years 9 months 10 days	'	'	'	'
Volatility	68.80%	'	'	'	'
Minimum	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Risk -free rate	1.43%	'	'	'	'
Maximum	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Risk -free rate	1.45%	'	'	'	'

Fair_value_measurements_Detail

Fair value measurements (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Derivative Liabilities, Noncurrent	$132,265	$389,454
Fair Value Assumptions Expected Volatility Rate	60.30%	72.80%
Fair Value Assumptions Risk Free Interest Rate	1.75%	0.74%
Fair Value Assumptions Expected Term (in Years)	'5 years	'5 years
Fair Value, Inputs, Level 3	'	'
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	'
Fair Value, Inputs, Level 3 | Warrant	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Fair Value Assumptions Expected Volatility Rate	62.10%	'
Fair Value Assumptions Risk Free Interest Rate	1.17%	'
Fair Value Assumptions Expected Term (in Years)	'1 year 11 months 16 days	'

Fair_value_measurements_Summar

Fair value measurements (Summary of Activity for the Period) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'
Fair value at December 31, 2012	$389,454
Fair value adjustment at December 31, 2013	-257,189
Fair value at December 31, 2013	$132,265

Reconciliation_of_Federal_Stat

(Reconciliation of Federal Statutory Income Tax Provision To Company's Actual Provision) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'
Benefit at federal statutory tax rate	($1,647,000)	($2,118,000)
Foreign rate differential	141,330	122,076
Unbenefited operating losses	1,505,670	1,995,924
Provision for income taxes	13,450	24,550
Income tax provision	$13,450	$24,550

Income_taxes_Schedule_of_Defer

Income taxes (Schedule of Deferred Tax Assets) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'
Net operating loss carryforwards	$9,902,000	$8,863,000
Accrued expenses and other	200,000	142,000
Stock compensation	1,014,000	745,000
Depreciation	-516,000	-661,000
Deferred tax assets and liabilties, net, before valuation allowance	10,600,000	9,089,000
Valuation allowance	-10,600,000	-9,089,000
Net deferred tax asset	$0	$0

Income_taxes_Details

Income taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
		Federal	Federal	State	Foreign
Operating Loss Carryforwards [Line Items]	'	'	'	'	'
Operating Loss Carryforwards	'	'	$25,191,000	$20,514,000	$2,635,000
Excess stock compensation deductions related to the amount of tax deductions on restricted stock in excess of book compensation expense	1,353,000	'	'	'	'
Amount of grant awards received under The American Recovery And Reinvestment Act	$285,718	$96,818	'	'	'

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Jul. 31, 2012	Dec. 31, 2013	Jun. 30, 2013	Jan. 31, 2006	Dec. 31, 2013
			sqft	Tecogen	Tecogen
			office
Commitment And Contingencies [Line Items]	'	'	'	'	'
Support Services Agreement, Service Period	'1 year	'	'	'1 year	'
Rental Income Related Party	'	$6,495	'	'	$6,495
Related Party Agreement, Period for Notice Termination	'60 days	'	'	'	'
Site Contingency Equipment Removal Cost	'	100,500	'	'	'
Depreciation Expense On Equipment Removal	'	$237,968	'	'	'
Related Party Agreement, Original Square Feet	'	'	3,071	'	'
Related Party Agreement, Square Feet	'	'	3,282	'	'
Related Party Agreement, Original Number of Offices	'	'	6	'	'
Related Party Agreement, Number of Offices	'	'	9	'	'

Subsequent_events_Details

Subsequent events (Details) (USD $)

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Jun. 14, 2013

Feb. 20, 2014

Dec. 31, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Jun. 14, 2013

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Feb. 20, 2014

Jun. 14, 2013

Feb. 20, 2014

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Unsecured Debt

Convertible Debt

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

EuroSite Power

Bruno Meier

Joan Giacinti

Charles T. Maxwell

Nettlestone Enterprises Limited

Senior Unsecured Convertible Notes Due 2015

Senior Convertible Notes Due 2017

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Unsecured Convertible Notes Due 2015

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Senior Convertible Notes Due 2017

Unsecured Debt

Convertible Debt

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Bruno Meier

Joan Giacinti

Charles T. Maxwell

Nettlestone Enterprises Limited

Subsequent Event

Bruno Meier

Joan Giacinti

Charles T. Maxwell

Nettlestone Enterprises Limited

Perastra Management Management S.A

Yves Micheli

Senior Unsecured Convertible Notes Due 2015

Senior Convertible Notes Due 2017

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

4.00%

4.00%

'

6.00%

'

'

'

'

'

'

'

'

'

'

'

4.00%

4.00%

Line of Credit Facility, Maximum Borrowing Capacity

$250,000

$300,000

$250,000

$300,000

'

'

$1,100,000

$1,100,000

$250,000

$300,000

$250,000

$300,000

$1,100,000

$250,000

$300,000

$250,000

$300,000

$1,500,000

$300,000

'

'

Debt Instrument, Face Amount

'

'

'

'

'

$4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

$4,000,000

$4,000,000

Debt Instrument, Convertible, Shares

'

'

'

'

'

1,667

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000

1,667