It sounds deceptively simple — drill a well into the Earth and bring piping steam or hot water to the surface to power a turbine that generates electricity, and in some parts of the world it is readily being used in this way. The resource also ticks multiple other boxes — it is renewable, it generates a fraction of the greenhouse emissions fossil fuels do, and unlike its solar and wind counterparts, it is not tethered to temperamental weather fluctuations.
The only problem is — we don’t always know where to drill, and even if we find the right places, the conditions needed to harness this form of energy aren’t always optimal, says Inga Berre, a professor at the University of Bergen in Norway. She is working on mathematical models that will help scientists move beyond exploiting easily accessible geothermal energy and access energy from so-called unconventional resources.
What is the current state of geothermal energy technology?
At the moment, a very small proportion of the total power generated globally comes from geothermal resources. This energy is most readily available in volcanically and/or tectonically active regions such as parts of the United States and Iceland. About 30 countries are currently using deep geothermal energy for electricity. (Overall), about 90 countries utilise (shallow or deep) geothermal energy for direct use, for example district heating.