Kaiser Permanente Purchases Two TECOCHILL Systems For Southern California Site TECOCHILL Systems for Anchore New Hybrid Cooling Plant for Hospital WALTHAM, Mass., July 12, 2004 - Tecogen Inc., a subsidiary of American Distributed Generation Inc., announced that Kaiser Permanente has purchased two high-efficiency water-cooled TECOCHILL® systems to replace an aging chiller plant at its Woodland Hills Medical Center in southern California. The TECOCHILL systems were chosen as the centerpiece of an innovative hybrid plant that will allow the hospital to alternate between different energy sources - electricity and natural gas - using whichever source is the most cost-effective at a given time. The hybrid chiller plant combines two large-scale chillers from Tecogen (400-ton cooling capacity each) with a conventional electric chiller. Powered by natural gas instead of electricity, the two TECOCHILL CH-400x units can provide cooling at a significantly lower cost than conventional electric chillers. The hospital will realize additional cost savings by using the waste heat generated by the units to produce all the hot water that the 218-bed hospital requires. The new plant replaces an aging chiller plant whose intermittent failures were disrupting the hospital’s operations. "Lead time and responsiveness were critical factors in the customer’s decision-making process," said Steve Lewis, director of Vertical Systems, Tecogen’s sales representative for the region. "At the same time, the cost of the new cooling system was still a key consideration." Mr. Lewis believes that the fast delivery time and the systems’ smaller footprint were both key factors in Tecogen being awarded the contract. 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 warmer 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. They use R-134A refrigerant, which is one of the most environmentally friendly refrigerants available. 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. based in Waltham, Massachusetts. For more information, go to www.tecogen.com. About American Distributed Generation, Inc. A privately held company based in Waltham, Massachusetts, American Distributed Generation provides a range of innovative products and services in support of the emerging market for on-site generation of electricity, heating, and cooling at commercial, institutional, and light-industrial facilities. In addition to TECOGEN® and TECOCHILL® equipment and field service, the company also offers customers an "on-site utility" option for the purchase of electricity and other energy services at prices below conventional utility rates. For more information, go to www.americandginc.com.