GEOTHERMAL EMERGING

The Importance of Geothermal Power
John Malone, August 27, 2009 (The Moderate Voice)

"…Geothermal power just hasn’t gotten the same respect [as wind and solar energies]. That could be changing, as both the Obama Administration and Silicon Valley are considering the heat under the ground as a potentially huge source of clean, domestic U.S. energy, but recent setbacks are calling into question how much geothermal can contribute. Given the potential benefits, we should be doubling our efforts…

"Some background: All thermal power plants use the same basic process. A heat source (burning coal or gas, uranium, concentrated solar energy)…[turns] water into steam, and the energy released turns a turbine that produces electricity…[But] geothermal steam comes directly from the ground. Water percolates down through cracks in the ground and is heated to the boiling point by hot rocks underground…[sometimes] as a geyser…and the resulting steam is drawn up via a well to a turbine."

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"This makes for, in principle, the ideal alternative energy source. Geothermal power releases virtually no CO2 or pollutants. Crucially, geothermal provides baseload power — wind and solar power are better suited as peaking technologies, as they are dependent on energy sources that wax and wane…Geothermal power is on 24 hours a day, 365 days a year…[and] can have utilization rates up to 98%…[In national security terms]…[t]here is no more domestic source of energy than the actual ground underneath us.

"…There are only a few places in the U.S. where you can find shallow groundwater hot enough to get steam directly from the ground…[but] Enhanced Geothermal Systems (EGS) make use of the fact that, if you drill deep enough, any bedrock in the world gets hot enough to boil water. Basically, EGS involves drilling a well into deep, hot, dry rock; drilling a second well nearby to the same depth; fracturing the rock between those two wells enough to allow water to pass between them; and then pumping water down the first well and allowing it to percolate through the hot fractured area to the second well, where it will come back to the surface as superheated steam. The potential for EGS in the U.S. is enormous. A 2006 MIT report concluded it could provide 100,000 MW of power by 2050."

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"…Cost is the main [EGS] hurdle. Oil and gas companies now measure well depths in miles, but these are wells drilled through relatively soft rock, not the hard granites that are best suited for EGS. If not managed properly, rocks could lose their heat — eventually, pumping water through a hot rock system could bring the heat gradient down to the point that new wells need to be drilled. There has also been some concern about earthquakes. In 2006, an EGS pilot project in Switzerland set off a 3.4 magnitude quake.

"…[T]hese hurdles are all surmountable, and given the huge benefits it could bring, there is already a surge in investment — both public and private…Google laid down an $11 million investment for early-stage research…[Thanks to Nobel Laureate Secretary of Energy, Steven Chu…Obama’s stimulus plan set aside $400 million for pure geothermal R&D. And…[a] recent NYU study found that as little as $3 billion in R&D development could make EGS cost-competitive with fossil fuel plants…[W]idespread application… is still a ways off. But…traditional [and] EGS…[can] be used alongside…wind and solar to diversify…There is no silver bullet…It’s better to think in terms of silver buckshot…[One solution is] right under our feet."