Currently known energy sources include: ① Solar radiation energy and the energy it converts into, including fossil fuels, wind power, hydraulic power, plant fuels, ocean waves, sea water temperature differences, etc.; ② The energy contained in the earth itself, Including atomic energy and geothermal energy; ③The energy generated by the interaction between the earth and other celestial bodies, such as tidal energy. The burning of fossil and plant fuels is the main cause of air pollution. Therefore, the use of non-polluting energy is an important measure to prevent air pollution. Non-polluting energy sources mainly include solar radiation, wind power, hydraulic power, geothermal energy, hydrogen fuel, bioenergy, and ocean waves, currents, seawater temperature differences, tides and other energy sources.