Earth's heat: Overview
Heat from deep inside, kept warm by radioactivity
Heat from deep inside, kept warm by radioactivity What this tile covers Heat from the Earth's interior, kept up by radioactive decay deep underground. Share of use 0.2% share of world energy supply (2024)Share of world total energy supply, 2024 (latest year where noted). Denominator is the Energy Institute Statistical Review 2025 total of 592.2 EJ (physical energy content method). Flows EI omits (traditional biomass via WBA, solar and geothermal heat, food energy) are set against the same 592.2 EJ, so shares sum to slightly more than 100%. Geothermal electricity 99 TWh plus direct heat 245 TWh = 1.24 EJ of 592.2 EJ (calculated). Source: Renewables 2025 Global Status Report: Geothermal, REN21.
Key facts
| Origin | Geothermal |
| Renewable | Yes, if managed well |
Included from the reference tables
- Hydrothermal
- Direct-use geothermal
- Enhanced geothermal
- Deep / supercritical geothermal
Also in Earth, gravity and atoms
Td TidesU UraniumD Fusion fuelsnH2 Natural hydrogenExplore paths from here
More on this tile in the tabs above: how energy resides, abundance, fluctuation in time, across the earth, impact on nature.