Posted at 12:18 p.m. on July 18, 2014
From Energy Department – EERE video
The Energy Department is spending $31 million to move forward with hydraulic fracturing to produce electricity from rocks.
Geothermal electric generation has traditionally tapped deep underground reservoirs of water that are heated by the earth. Hot pressurized water is brought to the surface where it turns to steam that can generate electricity. But there are a limited number of locations with such reservoirs.
Using similar processes that petroleum producers use to release oil and gas from tight formations, the department is researching methods of creating fracture networks to make underground reservoirs where there were none, drastically increasing the areas where geothermal power could be profitable.
The money will establish a laboratory that will be “a first-of-its-kind effort to accelerate development of this innovative geothermal technology that could help power our low carbon future,” Dave Danielson, assistant secretary for energy efficiency and renewable energy, said in a statement.
“This field observatory will facilitate the development of rigorous and reproducible approaches that could drive down the cost of geothermal energy and further diversify our nation’s energy portfolio,” he said. The department estimates the eventual potential of enhanced geothermal to be 100 gigawatts, in the same ballpark as the currently capacity of existing nuclear or hydroelectric plants.
A description of the reservoir creation process from the department:
Drill an injection well into hot rock with limited fluid content and/or permeability.
Inject water at sufficient pressure to create a fracture network.
Continue operation until there is enough fractured volume to create a reservoir.
Drill a production well into the fracture network, intersecting the created flow paths.
The resulting circulation loop allows water to flow through the enhanced reservoir, picking up in situ heat. The hot water is then pumped to the surface through the production well.
More Money for Geothermal Fracking