Geothermal cranks up the heat

But do these systems make sense in the Pacific Northwest?

By Steve Law

Pamplin Media Group, Oct 16, 2008, Updated Oct 30, 2009

With a geothermal system, water is pumped through copper or plastic tubes buried below ground, warming it to 55 degrees. The thermal reservoir can be used to warm a house in winter or to cool it in summer.

JONATHAN HOUSE / PAMPLIN MEDIA GROUP

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Some people look to the sun to shrink their home’s carbon footprint.

Wendell Pierce is looking under the ground.

Pierce, an orthopedic surgeon relocating from Boston, plunked down $25,000 to install a geothermal heating system at the home he’s renovating in the South Tabor neighborhood. He figures it will cut his energy bills in half.

“It seems like the right thing to do,” says Pierce, who enjoyed the benefits of solar panels for years at his suburban Boston home.

Alarmed by soaring energy prices and the omnipresent specter of global warming, more homeowners are exploring geothermal systems, also known as ground-source heat pumps.

Local contractors report bustling business. “It’s time has definitely come,” says Steve Permetti, who works on geothermal systems for Specialty Heating & Cooling Inc. of Tigard.

“It’s definitely booming,” says Dave Brook, an analyst for the Oregon Department of Energy. “We’re getting lots of calls about them.”

Although the state has issued just 2,313 tax credits for geothermal systems since 1978, he says, the real number of installed systems is far higher, because many homeowners never seek the tax break.

Energy experts say that geothermal power offers genuine advantages in extreme climates. But the recent surge of interest comes despite real questions about whether geothermal systems pencil out for homeowners in the Pacific Northwest.

How it works

Traditional geothermal systems are massive commercial ventures that drill miles underground to tap heat from natural pockets of hot water, steam or rock.

Residential geothermal systems operate on a similar principle, but a different level – just a few feet below ground.

“If you dig down about five feet below the surface in Oregon, you will get a stable temperature of 55 degrees,” says Pearl District home designer Paul “Paolo” Scardina. “That five feet of crust is acting as a thermal blanket.”

Residential geothermal systems pump water through loops of copper or durable plastic buried below ground, warming it to 55 degrees. This thermal reservoir can be used to warm a house in winter or to cool it in summer.

As a result, geothermal systems use less energy and the equipment lasts longer. “If you get past the initial cost of installing it, it’s anywhere from three to six times more efficient than a standard furnace system,” Scardina says.

Permetti figures the systems should be a “no-brainer” for new homes and major remodels. Monthly energy savings will exceed the cost of paying for the system via a home loan, he says, “so you’d be in the black immediately.”

Scott Banford, who owns Northwest Geo in Boring and installed Pierce’s system, is more bullish about the systems he’s installed.

“On the average, the homes have realized a 60 percent savings in their heating costs and cooling,” Banford says. “You’ll typically have a four- to seven-year payoff in that system at today’s energy costs.”

Experts advise caution

There’s no denying the systems dramatically reduce energy bills. But experts caution that the systems are expensive and industry claims can be overstated.

“In our climate zone, geothermal heat pumps are a fairly expensive alternative to a regular electric heat pump or some sort of gas system,” says Steve Lacey, director of energy efficiency for the Energy Trust of Oregon. “It’s a very, very long payback. I would say that it’s well over 10 years.”

The nonprofit group gives rebates to consumers who invest in energy conservation, using money garnered from a 3 percent “public purpose” surcharge on ratepayers’ bills.

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