Abstract: A power generation plant including a solar radiation receiver for heating a medium stream and a turbine assembly being arranged to receive the heated medium stream from the solar radiation receiver, said turbine assembly being coupled to an electric power generator, wherein a combustor is positioned downstream of the solar radiation receiver and upstream of the turbine assembly, an air compressor unit having a compressed air outlet is arranged to supply compressed combustion air to the combustor, and a steam generator is arranged to extract heat from an outlet flow from the turbine assembly, and to produce steam to be transmitted to a medium stream inlet of the solar radiation receiver and subsequently to combustor. The invention also related to a method.

Abstract: A method of operating a gas turbine power plant comprising of a first gas turbine group, consisting of a compressor and a turbine which are connected mechanically with one another, and a second gas turbine group, including a combustion device, which is placed in the gas flow stream between the first group's compressor and turbine, whereby the second gas turbine group consists of a compressor, a fuel injection device, a combustion chamber and a turbine, whereby the second gas turbine group's compressor and turbine are mechanically coupled to one another and at least one of the gas turbine groups having a device for the extraction of work, whereby the fact that a first flow of water and/or steam is heated with heat from the flue gas from the first group's turbine, that further amounts of water and/or steam are heated with heat from a gas stream that is compressed by the first group's compressor, and the produced water and/or steam is injected into the gas stream in such amounts that at least 60% of the oxygen c