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 content of the air in the stream is consumed through
combustion in the combustion device, and in that the combustion gas that is fed into the turbine of the second gas turbine group has a pressure in the range 50-300 bar.