The Earth's interior is a reservoir of thermal energy, primarily generated from radioactive decay processes. This energy manifests as heat, and in certain areas of the world, it's closer to the surface, making it more accessible.

Geothermal systems harness this underground heat by circulating a fluid through a series of pipes buried deep in the ground. In the winter, the fluid absorbs the Earth's warmth, which is then extracted and used to heat buildings. In the summer, the process can be reversed, with the system extracting heat from buildings and dissipating it into the ground.

The beauty of geothermal energy is its consistency. Unlike solar and wind, it doesn’t rely on weather conditions. It offers a stable and reliable energy source that can significantly reduce our reliance on fossil fuels, cut down energy bills, and reduce greenhouse gas emissions.