Tecogen Files Lawsuit Against Aegis Energy Services WALTHAM, Mass., September 12, 2005 - Tecogen Inc., the leading manufacturer of small natural gas-driven cogeneration modules, announced today it has filed suit in the U.S. District Court of Massachusetts against Aegis Energy Services Inc. (also known as Aegenco and Aegis Generation), for unfair competition and unfair and deceptive acts, patent infringement, common law copyright, and copyright infringement of software and manuals. The suit alleges that Aegis has taken advantage of its position as a Tecogen distributor to copy Tecogen’s software, product designs and intellectual property, and has illegally used this propriety information to create and sell "knock-off" modules in place of Tecogen’s modules. "Tecogen will aggressively enforce its patent and intellectual property to protect the interests of our company, customers, and investors," said Robert Panora, president of Tecogen. "Companies must compete on the basis of innovation and according to the laws of the land. Tecogen spent years and invested heavily in developing its natural gas-driven products. Our intention was to serve our customers and investors, not be the R&D department for our dealers, distributors, and competitors. Aegis, a former Tecogen distributor, must play by rules and stop infringing on our intellectual property." Mr. Panora continued, "We are taking this action to protect our interests and our reputation as an innovative and dependable supplier of cogeneration technology, earned for the hundreds of machines and millions of operating hours for which Tecogen products are well known." Tecogen initially designed its CM-60 TECOGEN® unit in 1977. By 1987, one million total run hours were logged on Tecogen units at actual customer sites. A year later, the company introduced the CM-75 High Output unit. In 1990, the company sold its first low-emissions module in Southern California, followed by the introduction of the TecoNet(TM) state-of the-art microprocessor control system in 1998. In 2002, the company’s cogeneration modules were certified by ITS/ETL Semko, an OSHA-approved NRTL (Nationally Recognized Testing Laboratory for product safety certification), to be in compliance with national IEEE P1547/DO7standards, "type-tested and approved" under NY State Interconnection Requirement, and successfully completed testing for compliance with California’s Rule 21. About Tecogen Tecogen operates in the distributed generation market and is a leading manufacturer of natural gas-fueled commercial and industrial cooling and cogeneration systems. Tecogen has a nationwide installed base of more than 1,800 units, which it supports through an established network of engineering, sales, and service support. Tecogen is a subsidiary of American Distributed Generation Inc. (www.americandginc.com) based in Waltham, Massachusetts. For more information, go to www.tecogen.com.