Fears persist that cracking rock deep underground through hydroshearing can also lead to damaging quakes. EGS has other problems. It is hard to create a reservoir big enough to run a commercial power plant.
Progress has been slow. Two small plants are online in France and Germany. A third in downtown Basel, Switzerland, was shut down over earthquake complaints. A project in Australia has had drilling problems.
A new international protocol 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 hopes to demonstrate a new technology for creating bigger reservoirs that is based on the plastic polymers used to make biodegradable cups.
It worked in existing geothermal fields. Newberry will show if it works in a brand new EGS field, and in a different kind of geology, volcanic rock, said Colin Williams, a USGS geophysicist also in Menlo Park.
The U.S. Department of Energy has given the 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.”<< previous 1 2 3 4 next >>
Comments are closed