Renewable energy such as geothermal energy has long been held back by energy kings such as cheap natural gas, weak demand for power and declining political concern over global warming and it’s effects. Efforts to use the earth’s heat to generate power, known as geothermal energy, have been further hindered by technological issues and concerns that some of the techniques used to tap into it can create earthquakes.
Keeping that in mind, the federal government, Google and other investors are still interested enough in the technology to wager $43 million on the Newberry Volcano Oregon project. They are helping the company, AltaRock Energy, Inc. of Seattle and Davenport Newberry Holdings LLC of Stamford, Conn., who runs Newberry Geothermal, demonstrate whether the next level in geothermal power development can work on the flanks of Newberry Volcano, located about 20 miles south of Bend, Ore.
Susan Petty, president of AltaRock Energy stated: “We know the heat is there. The big issue is can we circulate enough water through the system to make it economic.”
Geothermal EnergyFor hundreds of years geothermal energy in the form of heat from the earth’s crust has been used to generate power. Engineers collect the hot water or steam that bubbles up to or near the surface and use it to spin turbines that creates electricity. Most of those areas however have already been exploited. The new frontier for geothermal energy is in places with hot rocks, but without cracks in the rocks or the water to deliver the steam.
To tap into that heat source, and potentially grow geothermal energy from a tiny niche into an important source of green energy, engineers are now working on a new technology called Enhanced Geothermal Systems (EGS).
Research geophysicist Steve Hickman who is with the U.S. Geological Survey in Menlo Park, CA stated: “To build geothermal in a big way beyond where it is now requires new technology, and that is where EGS comes in.”
Wells are drilled deep into the rock and the 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.
For those of you wondering, doesn’t this technology sound like hydraulic fracturing which is used to obtain natural gas embedded in shale rock formations? I know I am! In fact, hydroshearing is very similar to the process known as hydraulic fracturing, however fracking uses water laced with chemicals, and in the process creates huge fractures, and the pumping of fracking wastewater deep underground for disposal more than likely led to a recent rash of fracking earthquakes in Arkansas and Ohio.
With that being said, of course there are fears still persistent that cracking the rock deep underground through the process of hydroshearing also can lead to damaging quakes. EGS also has to face other problems, as it is extremely hard to create a reservoir big enough to run a commercial power plant.
Progress for EGS has been slow in the making, with only two small plants operating online in France and Germany. A third EGS plant in downtown Basel, Switzerland, was shut down permanently due to earthquake threats in December 2009. A project in Australia has had drilling problems, however, Geoscience Australia estimates that by exploiting just 1% of the geothermal heat resource within the top 5 kms of the Earth’s crust they could provide 26,000 times their annual energy consumption.
According to the AP, a new international protocol developed for the IEA is coming out at the end of this month that urges EGS developers to keep projects out of urban areas, the so-called “sanity test,” said Ernie Majer, a seismologist with the Lawrence Berkeley National Laboratory. It also urges developers to be upfront with local residents so they know exactly what is going on.
AltaRock Energy hopes to demonstrate a new technology for creating bigger reservoirs that is based on the plastic polymers used to make biodegradable cups. It has worked in existing geothermal fields and Newberry will be able to show if it works in a brand new EGS field, and in a different kind of geologic formation such as volcanic rock, said Colin Williams, a USGS geophysicist also in Menlo Park.
The U.S. Department of Energy has given the geothermal energy project $21.5 million in stimulus funds. That has been matched by private investors, among them Google with $6.3 million.
Majer said the danger of a major quake at Newbery is very low. The area is a kind of seismic dead zone, with no significant faults. It is far enough from population centers to make property damage unlikely. And the layers of volcanic ash built up over millennia dampen any shaking.
But the Department of Energy will be keeping a close eye on the project, and any significant quakes would shut it down at least temporarily, he said. The agency is also monitoring EGS projects at existing geothermal fields in California, Nevada and Idaho.
“That’s the $64,000 question,” Majer said. “What’s the biggest earthquake we can have from induced seismicity that the public can worry about.”
Geologists believe Newberry Volcano was once one of the tallest peaks in the Cascades, reaching an elevation of 10,000 feet and a diameter of 20 miles. It blew its top before the last Ice Age, leaving a caldera studded with towering lava flows, two lakes, and 400 cinder cones, some 400 feet tall.
Although the volcano has not erupted in 1,300 years, hot rocks close to the surface drew exploratory wells in the 1980s.
Over 21 days, AltaRock will pour 800 gallons of water per minute into the 10,600-foot test well, already drilled, for a total of 24 million gallons. According to plan, the cold water cracks the rock. The tiny plastic particles pumped down the well seal off the cracks. Then more cold water goes in, bypassing the first tier, and cracking the rock deeper in the well. That tier is sealed off, and cold water cracks a third section. Later, the plastic melts away.
Seismic sensors produce detailed maps of the fracturing, expected to produce a reservoir of cracks starting about 6,000 feet below the surface, and extending to 11,000 feet. It would be about 3,300 feet in diameter.
The U.S. Bureau of Land Management released an environmental assessment of the Newberry project last month that does not foresee any problems that would stop it. The agency is taking public comments before making a final decision in coming months.
No power plant is proposed, but one could be operating in about 10 years, said Doug Perry, president and CEO of Davenport Newberry.
EGS is attractive because it vastly expands the potential for geothermal power, which, unlike wind and solar, produces power around the clock in any weather.
Natural geothermal resources account for about 0.3 percent of U.S. electricity production, but a 2007 Massachusetts Institute of Technology report projected EGS could bump that to 10 percent within 50 years, at prices competitive with fossil-fuels.
Few people expect that kind of timetable now. Electricity prices have fallen sharply because of low natural gas prices and weak demand brought about by the Great Recession and state efficiency programs.
But the resource is vast. A 2008 USGS assessment found EGS throughout the West, where hot rocks are closer to the surface than in the East, has the potential to produce half the country’s electricity.
“The important question we need to answer now,” said Williams, the USGS geophysicist who compiled the assessment, “is how geothermal fits into the renewable energy picture, and how EGS fits. How much it is going to cost, and how much is available.”
As for now, geothermal energy and enhanced geothermal systems are still in there infancy when it comes to research and operations, so we have a ways to go, but the future does look bright on the horizon with the development and testing of these newer technologies!