Summary of significant accounting policies - Revenue by Product Line and Services (Details)

v3.6.0.2

Summary of significant accounting policies - Revenue by Product Line and Services (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Revenue by Producks and Services [Line Items]
Products	$ 10,722,285	$ 10,055,237
Services	13,768,101	11,387,420
Total revenues	24,490,386	21,442,657
Cogeneration
Revenue by Producks and Services [Line Items]
Products	7,794,575	7,882,838
Chiller & Heat Pump
Revenue by Producks and Services [Line Items]
Products	2,927,710	2,172,399
Service contracts
Revenue by Producks and Services [Line Items]
Services	8,541,047	7,832,181
installations
Revenue by Producks and Services [Line Items]
Services	$ 5,227,054	$ 3,555,239

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	duration

- Definition

Aggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=tgen_ServiceContractsMember
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- Details

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Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies - Revenue by Product Line and Services (Details)