The world has an enormous untapped source of energy beneath its surface– geothermal energy. Using advanced technology, we could generate electricity by tapping into the heat stored in the Earth’s crust.
An enhanced geothermal system (EGS) produces electricity by tapping into geothermal energy even when natural heat, water, and rock permeability are not naturally present. Traditional geothermal systems rely on specific conditions, such as naturally occurring heat and water, along with permeable rock, to extract energy. However, most geothermal energy accessible with conventional methods is found in dry, impermeable rock.
EGS overcomes this limitation by using techniques like hydraulic stimulation to unlock and expand geothermal resources. For example, if you drill up to 8km deep, you could access enough heat to generate 300,000 exajoules of energy at a cost of less than US$300/MWh. That is equivalent to running nearly 600 terawatts of geothermal power for 20 years – a massive amount of energy that is 2,000 times more than what conventional geothermal methods can produce today.
Harnessing potential
According to a report published by the International Energy Agency (IEA), the United States has the world’s largest potential for enhanced geothermal energy technology, accounting for about one-eighth of the global total, with over 70 terawatts (TW) of capacity. Even at a depth of just 5km, the U.S. could harness over 7TW of geothermal energy – an amount seven times greater than the country’s current total installed power capacity.
Geothermal energy ranks second only to solar power in its potential to generate electricity. It offers almost three times the potential of onshore wind and five times that of offshore wind. To put things into perspective, geothermal energy could produce 150 times the electricity the world currently consumes each year, and that’s just from generating electricity. The leftover heat could also be used for heating buildings or powering industrial processes.
The deeper you drill, the more geothermal energy becomes available. For example, the technical potential for geothermal electricity at depths of less than 5km is an estimated 42TW of power capacity over 20 years. If we go deeper, between 5km and 8km, the potential skyrockets, offering 550TW of power capacity over the same period.
At shallow depths of around 2km, only a few countries with naturally hot underground conditions can effectively use geothermal energy for electricity. However, as we go deeper – beyond 7km – almost every part of the world has resources that could be tapped for clean, reliable energy.