Science
Geothermal Energy Quiz
Iceland, El Salvador, the Earth's heat — geothermal power and the green grid
Iceland, El Salvador, the Earth's heat — geothermal power and the green grid
Iceland gets 30% of its electricity and 90% of its home heat from geothermal — and the country has built greenhouses heated by Earth's interior to grow tomatoes near the Arctic Circle. Geothermal energy taps the heat generated by radioactive decay in Earth's mantle and residual primordial warmth, powering grids from California's Geysers to Kenya's Olkaria field, and heating district networks from Reykjavík to Boise.
Each round presents 10 randomized questions from a pool of 50, with four multiple-choice options and instant feedback after every answer. Your final score comes with a performance tier and shareable results.
You'll learn the differences between dry steam, flash steam, and binary cycle plants, explore Iceland and El Salvador as geothermal leaders, dig into Enhanced Geothermal Systems (EGS) and Fervo Energy's breakthrough Project Red, see how Microsoft's data-center deals are reshaping geothermal, and understand why ground-source heat pumps deliver about 400% efficiency.
The Geysers complex in northern California is the world's largest geothermal field, with around 1.5 GW of installed capacity across 18 dry-steam plants. The single largest individual plant in Europe is Iceland's Hellisheiði station at 303 MW.
Enhanced Geothermal Systems (EGS) drill deep into hot dry rock, fracture it hydraulically, and circulate water to harvest heat — letting geothermal work almost anywhere, not just near volcanic hotspots. Fervo Energy's Project Red in Nevada/Texas brought the first commercial EGS power online in 2023.
Two main ways: district heating systems pipe hot water from geothermal wells directly to buildings (as in Reykjavík), and ground-source heat pumps exchange heat with the ~10°C subsurface to warm or cool individual homes — delivering roughly 4 units of heat per 1 unit of electricity.
Last updated: May 2026