🌋Volcanic areasIceland gets about a quarter of its electricity and most of its heating from geothermal.

♨️Hot springs & geysersSigns of heat close to the surface.

🏠Heat pumpsEven ordinary ground 2 m down stays about 10°C all year; home systems use it for heating and cooling.

✅ProsRenewable, works day and night, very low emissions.

⚠️ConsOnly practical in some places; drilling is expensive.

🌡️SourceHeat left from Earth’s formation plus radioactive decay inside.