A method of generating fuel for use in a combustor of a gas turbine includes generating an exhaust gas by a first combustor, generating reformate comprising hydrogen, and generating a fuel that is a gas mixture of the reformate and exhaust gas from the first combustor, and using the fuel in a combustor in a gas turbine. The reformate may be generated in dependence on at least some of the heat generated by the first combustor. The method may also include supplying air that has not been oxygen depleted and combusting the supplied air and fuel in the combustor of the gas turbine.