In this study, an advanced cogeneration system (ACGS) composed of three turbine systems and an ammonia absorption refrigerator is presented. The overall system configurations and some experimental results of the steady state are shown. The effectiveness of the bottoming stage that employs an ammonia-water mixture (AWM) as the working fluid is confirmed by experimental investigation. The experimental investigation shows that the AWM bottoming power-refrigeration cycles contributes to a higher bottoming efficiency, which is about 7.0% in electric power. Otherwise. the efficiency at the middle stage in conventional combined gas and steam turbine power plants is 4.6%. The cogeneration efficiency at the bottoming reached about 26.5% which is the heat and power ratio to the heat input from the heat recovery steam generator. (C) 2004 Elsevier Ltd. All rights reserved.