Tecogen Cogeneration Systems Purchased by American DG Energy

         Tecogen Cogeneration Systems Purchased by American DG Energy

PR Newswire

WALTHAM, Mass., May 24, 2012

WALTHAM, Mass., May 24, 2012 /PRNewswire/ --Tecogen Inc. today announced that
American DG Energy Inc. has purchased 13 Tecogen combined heat and power (CHP)
units for use in a variety of new energy production projects announced earlier
this month by ADGE. The Tecogen systems comprise eight CM-75 (75 kW) and five
InVerde (100 kW) units.

"Tecogen was the natural choice for our clients," said Barry Sanders,
president and chief operating officer of American DG Energy. "Tecogen is the
pre-eminent bridge to a sustainable energy future, whose products are proven,
cost-effective and environmentally responsible."

Six of the CM-75 units will comprise a cogeneration plant to be placed at
Tracy Towers residential apartment complex in New York. One CM-75 unit will
be providing electricity, domestic hot water, space heating and pool heating
to the Greenwich YMCA in Connecticut. Another CM-75 unit will be sited at the
West Village Apartments in Connecticut. The five InVerde units will be
installed in the United Kingdom by EuroSite Power, a European subsidiary of
American DG Energy.

About Tecogen Inc.
Tecogen manufactures highly efficient, ultra-clean Combined Heat and Power
products including natural gas engine-driven cogeneration, air conditioning
systems, and high-efficiency water heaters for industrial and commercial use.
Tecogen has an installed base of more than 2,100 units, supported by an
established network of engineering, sales, and service personnel across the
United States. For more information, please visit www.tecogen.com.

FORWARD-LOOKING STATEMENTS
This press release contains forward-looking statements under the Private
Securities Litigation Reform Act of 1995 that involve a number of risks and
uncertainties. Important factors could cause actual results to differ
materially from those indicated by such forward-looking statements, as
disclosed on the Company's website and in Securities and Exchange Commission
filings. The statements in this press release are made as of the date of this
press release, even if subsequently made available by the Company on its
website or otherwise. The Company does not assume any obligation to update the
forward-looking statements provided to reflect events that occur or
circumstances that exist after the date on which they were made.

Tecogen Media Contact
Information:
Melinda M. Furse
Tecogen Inc.
P: 781-466-6444
E: melinda.furse@tecogen.com 

Tecogen Investor Contact Information:
John N. Hatsopoulos
P: 781-622-1120
E: jhatsopoulos@tecogen.com

SOURCE Tecogen Inc.