With the attention to environmental problems growing in recent years, demand has grown to reduce the emission of CO₂ gas, which contributes largely to global warming. For thermal power plants, CO₂ emission is reduced by making power generation more efficient. Mitsubishi Heavy Industries, Ltd., (MHI) has improved power generation efficiency in conventional coal-fired thermal power plants by improving steam conditions and adopting advanced technologies. MHI is also improving the efficiency by using gas turbines and gas engines. This paper summarizes on sophisticated use of coal energy with green technologies for thermal power plants, I.e. advanced coal-fired ultra supercritical (USC) thermal power generation, integrated gasification combined cycle (IGCC), the blast furnace gas-fired gas turbine combined cycle, and gas engine power generation using coalmine methane.