A power plant system including a fossil fuel fired power plant (6) for the generation of electricity, a carbon dioxide capture and compression system (5, 13), and an external heat cycle system has at least one heat exchanger (1,2,3) for the heating of the flow medium of the external heat cycle system. The heat exchanger (1,2,3) is connected to a heat flow from the CO2 capture plant (5) or a CO2 compression unit (13). A return flow from the heat exchanger (1,2,3) is led to the CO2 capture and compression system (5,13) or to the power plant (6). The power plant system allows an increase in overall efficiency of the system.