Annual report pursuant to Section 13 and 15(d)

Commitments and contingencies - Agreement with Digital Energy Corp. (Details)

v2.4.1.9
Commitments and contingencies - Agreement with Digital Energy Corp. (Details) (USD $)
Oct. 26, 2011
Dec. 31, 2014
Financial guarantee    
Guarantor Obligations [Line Items]    
Letter of credit outstanding $ 180,000us-gaap_LettersOfCreditOutstandingAmount
/ us-gaap_GuaranteeObligationsByNatureAxis
= us-gaap_FinancialGuaranteeMember
 
Certificate of deposit securing letter of credit 180,000us-gaap_CertificatesOfDepositAtCarryingValue
/ us-gaap_GuaranteeObligationsByNatureAxis
= us-gaap_FinancialGuaranteeMember
 
Promissory note receivable amount 180,000us-gaap_NotesAndLoansReceivableGrossNoncurrent
/ us-gaap_GuaranteeObligationsByNatureAxis
= us-gaap_FinancialGuaranteeMember
 
Promissory note receivable, stated interest rate 6.00%tcgn_LoansReceivableInterestRateStatedPercentage
/ us-gaap_GuaranteeObligationsByNatureAxis
= us-gaap_FinancialGuaranteeMember
 
Revolving credit facility    
Guarantor Obligations [Line Items]    
Letter of credit outstanding   583,702us-gaap_LettersOfCreditOutstandingAmount
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
Chief Executive Officer (John N. Hatsopoulos) | Letter of credit    
Guarantor Obligations [Line Items]    
Collateralized financings   $ 1,055,000us-gaap_CollateralizedFinancings
/ us-gaap_CreditFacilityAxis
= us-gaap_LetterOfCreditMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= us-gaap_ChiefExecutiveOfficerMember