Still searing from the formation of the solar system, the core of Earth is a nuclear reactor generating heat from the breakdown of radioactive elements like uranium, thorium, and potassium. Scientists have been harnessing that heat for decades by drilling deep wells to power turbines. But now researchers have been able to tap into even greater energy by drilling into volcanoes and exploiting the heat of molten rock. If current geothermal wells are replaced with the new technology, it could provide 30% more power than current renewable energy sources.

The idea of tapping the energy of magma came from a pair of accidents. In 1985, workers drilling for a geothermal well in Iceland ran into a sudden and uncontrollable blast of high-pressure steam. Scientists think the steam originated from a reservoir of water that’s under such pressure that as it begins to boil, the water cannot expand enough to become vapor and remains in a liquidlike state. Water in such a “supercritical state” contains enormous amounts of energy. Water reaches this state once it reaches 222 bars of pressure and 374°C or above, and flashes into steam when the pressure drops as the water rises to the surface.