Thermal power refers to the energy that is generated by converting heat into electricity. It is the process of producing electricity from a primary source of heat by using a steam turbine. Thermal power stations are a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle, heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a steam turbine. The design of thermal power stations depends on the intended energy source, which can be fossil fuel, nuclear and geothermal power, solar energy, biofuels, and waste incineration. Natural gas is frequently burned in gas turbines as well as boilers. The majority of electricity in Japan is provided by thermal power generation, which uses a wide variety of fuels such as liquefied natural gas (LNG), liquefied petroleum gas (LPG), heavy oil, crude oil, and natural gas liquid (NGL), as well as coal.

Thermal power stations can be quite inefficient, meaning the electrical energy at the end of the process is less than the amount of electrical energy that could be produced from the original fuel; energy is lost along each stage of the process. This energy is usually lost as heat energy. Because of this, scientists and researchers are looking into new ways of not wasting this heat energy. Recycling water and heat is one way to reduce the inefficiency of thermal power stations.

Overall, thermal power is a widely used method of generating electricity due to the abundance and accessibility of fossil fuels. However, it is also a significant contributor to greenhouse gas emissions and environmental pollution. Efforts are being made to reduce the environmental impact of thermal power by developing more efficient and cleaner energy technologies such as solar, wind, and geothermal power.