Officials with the company trying to create a geothermal resource south of Bend say they’re moving closer to power production but first need more testing and more funding. Any power coming from Newberry Volcano is still years away.
Seattle-based AltaRock Energy started cracking hot rock deep within Newberry Volcano two years ago by pouring water down a 10,000-foot well. It stopped in late 2012 because of weather and didn’t do any work in 2013 so scientists could examine data and crews could reinforce a steel and concrete casing extended 5,300 feet into the well, said Dave Stowe, an AltaRock Energy spokesman.
“It took some time,” he said.
AltaRock restarted the work Sept. 23 and it could continue until early November if weather allows, said Trenton Cladouhos, senior vice president in charge of research and development for the company.
The project site is about 10 miles northeast of La Pine, between U.S. Highway 97 and Paulina Lake.
A traditional geothermal site relies on steam emitting from the earth, with a power plant using the steam to turn a turbine. Exploratory drilling into Newberry Volcano in recent years found plenty of hot rock but no steam. By cracking the rock, which has temperatures around 600 degrees, more surface area becomes available to heat water.
AltaRock plans to build a geothermal resource based on the system of cracks. After completing the crack system the company will pour water down an injection well, let it heat in an underground reservoir and then pull it up a separate well as steam.
“We are filling up the reservoir and we’ll drill into it next year if everything goes right,” Cladouhos said.
So far AltaRock has created a network of cracks fanning out 1,000 feet from the injection well.
Once a well at the site produces steam, a power plant could be added, Stowe said. Covering the cost of building a power plant will take finding investors and acquiring the proper federal permits and approval.
The system nearing completion could support a 7- to 15-megawatt power plant, Stowe said. One megawatt of power is enough to provide electricity for about 1,000 homes. Cost will be in the millions of dollars, with a 10-megawatt plant costing $22 million to build and even more to connect to the nearest transmission line.
AltaRock has more room to put in wells at a collection of three pads, forest clearings made to house drilling and pumping equipment, on Newberry Volcano, giving it the potential to someday produce as much as 100 to 150 megawatts.
Critics of the company’s plans have said the project could cause problems with groundwater and trigger earthquakes.
Cladouhos and Stowe said neither issue has occurred. Stowe said thousands of feet of rock separate the aquifer, or natural underground reservoir, and the reservoir being created.
In tracking the spread of the cracks, scientists use sensitive seismology gear to map vibrations in the ground. Cladouhos said the strongest of this was near magnitude 2. Earthquakes typically aren’t felt until magnitude 3.5.
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