Snohomish County PUD to probe for sources of geothermal energy

  • Sun Aug 15th, 2010 9:53pm
  • News

By Bill Sheets Herald Writer

EVERETT — This fall, the Snohomish County PUD will be one step closer to knowing if geothermal energy could be tapped here.

The utility is planning to drill five test wells in the Cascade Range as soon as the end of this month. It’s believed the wells will indicate whether there’s enough hot water below the surface to warrant more drilling.

Geothermal power is created when steam, heat or hot water from underground reservoirs is used to spin turbine generators. The hope is that geothermal electricity could potentially provide power for up to 35,000 homes in Snohomish County by 2020.

The utility won’t know for sure if enough hot water exists below the surface of the Cascades to produce geothermal power, but officials say it’s worth finding out.

“We think it’s important to look,” said Craig Collar, senior manager for energy resource development for the PUD.

The test wells, located near Skykomish and Sultan, will be drilled to measure the rise in temperature from the surface to the bottom of each well.

The test-well sites likely would not be candidates for a geothermal plant in the future. They were selected because they’re near roads and are easy to reach, Collar said.

“They’re only going to point us in the right direction in terms of where to do additional drilling,” he said.

Officials already have some geological information about the area, and the wells will provide more.

“It’s just one piece of the whole picture,” he said.

The data from the wells should tell PUD officials what they want to know by this fall, Collar said.

Two of the sites are on private property, two on U.S. Forest Service land and one on land owned by the state, he said.

The PUD will spend $250,000 to dig the wells, spokesman Neil Neroutsos said. Up to half of that cost could be covered by funds from the U.S. Department of Energy, he said.

Ultimately, a 50-megawatt plant — the size needed to generate power for 35,000 homes — would cost between $150 million and $200 million, Collar said. An unknown portion of that total potentially could be covered by federal funds, Neroutsos said.

While officials estimate geothermal power could provide only about 6 percent of the PUD’s output, it’s part of a larger plan by the utility to increase its percentage of renewable, environmentally friendly energy. The PUD also is working on a pilot project for tidal power, is buying wind power from private developers in the Columbia Gorge and has a solar-panel incentive program.

The utility is shooting for producing or obtaining 16 percent of its power from geothermal, wind, tidal and biomass sources by 2020. Most of the PUD’s power comes from dams.

In 2006, voters approved Initiative 937, which requires the state’s major utilities to produce 15 percent of their electricity from renewable resources such as wind and geothermal by 2020. Power from dams doesn’t count.

Bill Sheets: 425-339-3439; sheets@heraldnet.com.