In this paper, the performance of solar energy powered transcritical cycle using supercritical carbon dioxide for a combined electricity and heat generation, is studied experimentally. The experimental set-up consists of evacuated solar collectors, pressure relief valve, heat exchangers and CO2 feed pump. The pressure relief valve is used to simulate operation of a turbine and to complete the thermodynamic cycle. A complete effort was carried out to investigate the cycle performances not only in summer, but also in winter conditions. The results show that a reasonable thermodynamic efficiency can be obtained and COP for the overall outputs from the cycle is measured at 0.548 and 0.406, respectively, on a typical summer and winter day. The study shows the potential of the application of the solar energy powered cycle as a green power/heat generation system. Copyright (c) 2006 John Wiley & Sons, Ltd.