Tuesday, January 24, 2012

Fracking For Geothermal Energy?

Newberry Crater, showing Paulina and East Lakes
Geothermal energy developers plan to pump 24 million gallons of water into the side of a dormant volcano in central Oregon this summer to demonstrate technology they hope will give a boost to a green energy sector that has yet to live up to its promise. They hope the water comes back to the surface fast enough and hot enough to create cheap, clean electricity that isn't dependent on sunny skies or stiff breezes — without shaking the earth and rattling the nerves of nearby residents.

Renewable energy has been held back by cheap natural gas, weak demand for power and lack of political concern over global warming. Efforts to use the earth's heat to generate power, known as geothermal energy, have been further hampered by technical problems and worries that tapping it can cause earthquakes. Even so, the federal government, Google and other investors are interested enough to bet $43 million on the Oregon project.

They are helping AltaRock Energy of Seattle and Davenport Newberry Holdings of Stamford, Conn., demonstrate whether the next level in geothermal power development can work on the flanks of Newberry Volcano, about 20 miles south of Bend, Ore.
Newberry Crater Obsidian Flow
Georgia and I spent a while out at Newberry Crater back a bazillion years ago when I was in Grad School in Oregon.  It's a very interesting place. On the eastern, dry side of the Cascade mountains, it's a caldera formed by the collapse of a huge volcano, much like the nearby Crater Lake.  It is much bigger in diameter than Crater Lake, and flatter, so that the outline of the base of the mountain can barely be detected. Coming down into the crater from the rim area are huge flows of obsidian, seen in the photo above. It glitters in the sun like the broken glass that it is.

Inside the crater are two lakes, Paulina and East, with reputedly excellent trout fishing.  We rowed around East Lake most a day without any luck, however.

To tap that heat — and grow geothermal energy from a tiny niche into an important source of green energy — engineers are working on a new technology called Enhanced Geothermal Systems.

"To build geothermal in a big way beyond where it is now requires new technology, and that is where EGS comes in," says Steve Hickman, a research geophysicist with the U.S. Geological Survey in Menlo Park, Calif.

Wells are drilled deep into the rock and water is pumped in, creating tiny fractures in the rock, a process known as hydroshearing. Cold water is pumped down production wells into the reservoir, and the steam is drawn out.

Hydroshearing is similar to the process known as hydraulic fracturing, used to free natural gas from shale formations. But fracking uses chemical-laden fluids, and creates huge fractures. Pumping fracking wastewater deep underground for disposal is suspected of leading to recent earthquakes in Arkansas and Ohio.
So, is fracking for renewable energy a good or bad thing?

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