Magma could become source of high-grade energy

Geologists discovered magma could become an attractive source of high-grade energy in the future. When drilling an exploratory geothermal well in 2009 in the Krafla volcano in Iceland, geologists were met with a big surprise when underground lava flowed into the well at 2.1 kilometers depth. It forced the scientists to stop drilling, they intended to go 4.5 kilometers deep to search for geothermal resources in the volcano but the accidental discovery gave them a unique opportunity to test a very hot geothermal system as an energy source:

"When the well was tested high pressure dry steam flowed to the surface with a temperature of 400 degrees Celsius or 750 degrees Fahrenheit, coming from a depth shallower than the magma," Elders said.

He and colleagues estimated that this steam could generate 25 megawatts of electricity if passed through a suitable turbine--enough electricity to power 25,000 to 30,000 homes.

"What makes this well an attractive source of energy," said Elders, "is that typical high-temperature geothermal wells produce only 5 to 8 megawatts of electricity from 300 degrees Celsius or 570 degrees Fahrenheit wet steam."

He believes it should be possible to find reasonably shallow bodies of magma, elsewhere in Iceland and the world, wherever young volcanic rocks occur.

"In the future these could become attractive sources of high-grade energy," said Elders.

More details at PhysOrg.