What is the source of geothermal energy?

Geothermal energy originates from the internal heat of the Earth. This heat can be traced back to the original formation of the planet, as well as the decay of radioactive isotopes within the Earth’s crust. This energy is harnessed by utilizing steam or hot water from underground reservoirs to generate electricity or provide direct heating.

The Earth's core remains extremely hot, and this geothermal energy can be found at varying depths, making it a significant and sustainable energy resource. It is especially effective in areas where tectonic activity is present, such as near volcanic regions. Geothermal energy is considered renewable because, unlike fossil fuels, it does not deplete the Earth’s resources nor does it contribute significantly to greenhouse gas emissions.

Other energy sources listed, such as solar energy, biomass, and fossil fuels, represent different methods of energy production that rely on various natural processes or materials. However, they do not tap into the Earth's internal heat like geothermal energy does.