CRAVEN REGIONAL MEDICAL CENTER CHOOSES ENVIRONMENTALLY FRIENDLY TECOGEN CHILLERS FOR ENERGY SAVINGS Tecogen's Natural-Gas Powered Systems Save Money and Reduce "Greenhouse Gas" Emissions WALTHAM, Mass., July 23, 2002 - Tecogen Inc. announced today that the Craven Regional Medical Center in New Bern, North Carolina, has chosen two 400-ton TECOCHILL® systems to support several older chillers that were no longer operating efficiently. The first natural gas-driven system was successfully installed in June, and just completed its first month of operation. "Our electric rate in New Bern is quite high, compared with other parts of the state," explained Fred Cohoon, vice president of operations at Craven Regional Medical Center. "Based on the long-range cost projections that our engineering firm prepared, we realized that we could significantly reduce our annual energy costs with a gas engine-driven chiller." A natural gas-driven chiller can offer very attractive energy efficiencies; a TECOCHILL system typically operates with greater than 90 percent efficiency. Since the engine is water-cooled, it can turn its "waste heat" into useful hot water, taking over the work of boilers and hot-water heaters. This, in turn, can lead to substantial cost savings, particularly in those parts of the country where high electric rates are prevalent. "Once the hospital decided to go with a gas chiller, they chose a manufacturer based on a matrix of key criteria," said Greg Carnathan, EI, a designer with RMF Engineering, Inc., in Durham, North Carolina. "The TECOCHILL systems clearly had an edge over the competition in terms of the cost savings they would provide for Craven." Based on a simple evaluation of the energy savings generated by both systems, it's estimated that the technology will pay for itself in less than three years. Tecogen's chillers allow commercial and industrial customers to significantly reduce their energy costs by running on natural gas, which is readily available during the summer months when demand for heating is low, but demand for air conditioning is high. The TECOCHILL systems are clean and non-polluting, and have successfully met the most stringent air-quality standards in the United States. And they use R-134a refrigerant, which is widely accepted throughout the industry and is one of the most environmentally friendly refrigerants available. About Tecogen Tecogen is the industry leader in natural gas-powered chillers, with more units installed and serviced than all other brands combined. These chillers are suitable for a variety of applications, including schools, universities, hospitals, office and apartment buildings, ice rinks, nursing homes, hotels, retailers, industrial facilities, and many others. Formerly a public subsidiary of Thermo Electron Corporation, the company is now privately held. Tecogen is based in Waltham, Massachusetts, with annual revenues of approximately $13 million.