Geothermal energy is renewable heat energy from the depths of the earth, which comes from the decay of molten magma and radioactive materials on the earth. After the deep circulation of groundwater and the intrusion of magma into the earth's crust from a very deep place, the heat is brought from the deep underground to the near surface. Its reserves are much more than the total energy used by people at present, and most of them are concentrated on the edge of tectonic plates, which is also a volcano and earthquake-prone area. It is not only pollution-free and clean energy, but also renewable under the condition that the heat extraction speed does not exceed the replenishment speed.
How to use this huge potential energy? Italian Prince Piero Ginoni Kong Di first used natural geothermal steam to generate electricity in Ladrero in 1940. Geothermal power generation is to inject water into the rock stratum by water pressure or blasting to generate high-temperature steam, and then take it out of the ground to push the turbine to rotate to make the generator generate electricity. In this process, a part of unused or waste gas is reduced to water by condenser treatment and sent back to the ground, and so on. 1990 installed power generation capacity reached 6000MW, and the total direct utilization of geothermal resources was equivalent to 4. 1Mt oil equivalent.