In 2009, engineers in Iceland were drilling an exploratory well near the Krafla volcano on the island’s northern coast when something entirely unexpected happened. The temperature in the borehole suddenly spiked to over 1000°C – hot enough to melt rock.
In fact, that’s exactly what they struck; a magma chamber. This was the first time that a drill hole in Iceland had ever run into an active, liquid magma chamber.
The hole was part of a project to explore for new geothermal energy resources, and obviously the engineers had hit something hot, so they decided to try something new. They lined the bottom of the borehole with steel and concrete to keep the magma from intruding into it and began pumping water down.
Earlier this year, it was reported they had successfully pulled it off. By pumping water into that borehole, they produced steam at a temperature of 450°C which could be contained and used as a geothermal energy source.
Much of Iceland’s power is supplied from geothermal sources, but this one is unique as it is the first ever recorded use of actual magma for geothermal recovery. In addition, most geothermal systems take energy from rocks that aren’t as hot as magma, but the hotter the steam, the more energy it can generate, so energy directly from magma is going to be much more efficient. The 450°C steam broke a record for the hottest steam ever used in electricity generation.
Engineers in Iceland have effectively produced the world’s first magma-driven geothermal system. It might not be a technique that can be replicated everywhere since most places don’t have active magma chambers beneath them, but it is a remarkable new engineering result.