Molten rocks powering your electronics?Geothermal energy constantly gets overshadowed by other sources of clean energy, like wind and solar, because it's still more expensive. But with every passing year, as more resources are invested in developing the technology, geothermal gets closer to its day in the spotlight. It's not hard to imagine a green future where it plays a big role, providing part of the "always on" baseload power to run our civilization.
One recent breakthrough in the field took place in Iceland. A borehold drilled in Krafla, in northeast Iceland, surprised engineers by penetrating magma (molten rock), something that had only happened once before, in Hawaii. Depth was 2100 meters and temperature was around 900-1000 Celsius. This provided a great opportunity to test the first ever magma-enhanced geothermal system!
“In the future, the success of this drilling and research project could lead to a revolution in the energy efficiency of high-temperature geothermal areas worldwide,” said Wilfred Elders, a professor emeritus of geology at the University of California. “Essentially, the IDDP-1 created the world’s first magma-enhanced geothermal system. This unique engineered geothermal system is the world’s first to supply heat directly from a molten magma.”
Several important things were learned with this project:
important milestones were achieved in this project: despite some difficulties, the project was able to drill down into the molten magma and control it; it was possible to set steel casing in the bottom of the hole; allowing the hole to blow superheated, high-pressure steam for months at temperatures exceeding 450 C, created a world record for geothermal heat (this well was the hottest in the world and one of the most powerful); steam from the IDDP-1 well could be fed directly into the existing power plant at Krafla; and the IDDP-1 demonstrated that a high-enthalpy geothermal system could be successfully utilized. (source)
While most geothermal energy resources don't have magma anywhere near the surface, they still offer potentially vast quantities of clean energy. The National Renewable Energy Lab (NREL) has created the following maps to show geothermal potential in the U.S.:
More details on those maps and bigger pictures can be found here.