What type of energy generation uses the Earth's internal heat?

Geothermal energy is derived from the Earth's internal heat, which originates from the natural decay of radioactive materials and from the residual heat of the planet’s formation. This energy can be harnessed by extracting steam or hot water from beneath the Earth's surface to generate electricity or to provide direct heating for various applications.

In contrast, wind energy relies on the kinetic energy of air movement caused by solar heating of the atmosphere. Solar energy harnesses sunlight using photovoltaic cells or solar thermal systems. Tidal energy is generated from the gravitational pull of the moon and sun on Earth’s oceans, and is not associated with the Earth's internal heat. Therefore, geothermal energy is unique among these choices as it directly utilizes the heat stored within the Earth.