A power plant has a coal gasification device for gasifying coal, particularly with water injection, a gas combustion device, particularly a CES burner, for combusting synthesis gas, particularly purified synthesis gas, from the coal gasification device, a hot gas expander for generating usable output power by expansion of flue gas from the gas combustion device, a steam generator, particularly a waste heat steam generator, for heating, particularly for evaporating and/or superheating, feedwater through exhaust heat of the expanded flue gas, a steam turbine set with at least a first stage for expanding steam, particularly high-pressure steam, from the steam generator, and a reheater which is arranged after the first stage of the steam turbine set and through which expanded flue gas flows. In this power plant, the cold rail of the reheater is throttled by a throttle device for constant pressure operation on the high-pressure side, and the steam parameters for the cold reheater rail are achieved by a conditioning valve for sliding pressure operation on the high-pressure side.