Storing excess energy is one of the energy transition’s big challenges. Geothermal energy storage can be one solution. It works by heating water and channeling the warm water back underground, where surrounding rock can retain the heat for up to months. Excess heat from solar power could also be used, stored underground, and retrieved when needed—even to generate electricity.
“Geothermal energy storage promises the almost universal availability of cheap and practically inexhaustible storage capacity.” – Peter Ruschhaupt, Cleantech Analyst
The costs for drilling to open underground caverns for storage make the initial investment high. However, estimates say the investment would pay off within two to ten years. Advances in drilling technology could further reduce costs, making geothermal storage a viable large-scale solution.
Learn more about the potential and challenges of geothermal heat storage in Germany in this article from Handelsblatt (in German, paywall) or read an abstract in Clean Energy Wire.
