01 How It Works
In high-temperature geothermal fields, steam from underground reservoirs (>150ยฐC) drives turbines directly. Lower-temperature resources use binary cycle plants - the geothermal fluid heats a secondary fluid with a lower boiling point, which vaporizes and spins the turbine. Enhanced Geothermal Systems (EGS) inject water into hot dry rock, fracturing it to create a reservoir - potentially opening geothermal to any location on Earth.
02 Pros & Cons
โ Advantages
- 24/7 baseload power
- Tiny surface footprint
- Long plant lifespan
- Low emissions
โ ๏ธ Disadvantages
- Geographically limited
- High drilling costs
- HโS gas risk
- Water use in some systems
03 Future Outlook
EGS is the game-changer. If successful, it could provide virtually unlimited clean baseload power anywhere. Companies like Fervo Energy and Quaise Energy are pioneering deep geothermal drilling using oil industry techniques and millimetre-wave energy. Iceland already gets ~70% of its primary energy from geothermal.
04 Fun Fact
Iceland heats 90% of its homes with geothermal energy, keeping heating costs among the lowest in Europe.