Geothermal Energy: Basics

Short: Geothermal energy uses heat stored inside the Earth to generate energy, such as for heating or electricity. This heat is nearly unlimited and independent of weather or time of day.

In more detail: The deeper you drill, the higher the temperature rises, on average by about 3 degrees per 100 meters.

In detail

• Near-surface geothermal: Ground heat probes or area collectors just a few meters deep supply heat for heat pumps in residential buildings.
• Deep geothermal: Drilling several kilometers down taps hot water or steam that can be used directly for electricity generation.
• Volcanically active regions: Countries like Iceland use particularly high near-surface temperatures for much of their energy supply.
• Year-round availability: Unlike sun and wind, geothermal delivers constant energy regardless of weather and season.
• Low land requirement: Geothermal plants need comparatively little surface area compared to solar or wind farms.
• Risks: Deep drilling can, in rare cases, trigger minor earthquakes, especially in geologically sensitive areas.
• High upfront costs: Development, especially for deep drilling, is costly but pays off through low operating costs over decades (waermepumpe, solarzelle-funktionsweise).