A turbine system and method for power generation has an electric generator, a reformer, a cooler, a fuel compressor, an air compressor, a combustor, a turbine, an evaporator. The reformer reforms fuel containing a mixture of hydrocarbon gas and steam to produce hydrogen and carbon dioxide. To enhance reformation, the reformation is carried out under pressure at 7 ata or less. To aid compression, the cooler cools the reformed fuel before the compressor compresses the reformed fuel. The combustor burns air compressed by the air compressor, which is driven by the turbine, and the reformed fuel received from the fuel compressor to generate hot gas. The turbine receives the hot gas from the combustor and drives the generator to generate electricity. The reformer receives the hot gas discharged from the turbine as a heat source to heat the fuel and chemically reform the fuel.