Energy from the ground up

Along 15th Street near Cherry, the din of the drilling has stopped for a while. Beyond the trucks and equipment is a wellhead. Fifteen feet along, another. Six in all.

The Friends Center is drilling 1,500 feet below the sidewalk - half again as deep as the Comcast tower is high - in search of energy savings.

The center will use the ambient temperature of the ground, about 50 degrees, to heat and cool the Quaker-run office complex.

The wells are costing $1.3 million, but the system will help eliminate the center's emissions of greenhouse gases and cut its energy costs by an estimated 46 percent. The payback period: six to eight years.

The technology, a geothermal heat-pump system, or geoexchange, has long been available. But with energy cheap, it hadn't been widely used.

Now, geoexchange has been quietly booming. Although estimates of total use vary, the annual delivery of geothermal heat-pump systems nearly doubled between 2004 and 2007, according to an industry analysis.

After growing more than 25 percent in 2005 and again in 2006, the pace slowed to about 9 percent in 2007, said Daniel Ellis, president of ClimateMaster Inc., an Oklahoma City-based manufacturer. He attributed the slackening to reductions in new housing construction and a lack of installation capacity.

With geoexchange no longer viewed as such an odd duck, and with soaring energy costs for heating and cooling, the systems' up-front cost isn't such a shock.

"Many institutions are going to be brought totally to their knees by the price of energy," said Patricia McBee, director of the Friends Center capital campaign.

Advocates call geothermal the reliable renewable - the sun doesn't have to shine, the wind doesn't have to blow.

"It's the energy we already own," said Jack DiEnna, executive director of the Geothermal National and International Initiative.

The term geothermal - literally, "earth heat" - applies to many processes. For example, steam or superheated water from underground can be used to drive turbines to produce electricity.

Geothermal heat-pump systems heat and cool but don't produce electricity. All are variations on a theme: Liquid circulated through the ground is warmed in the winter and cooled in the summer.

Above ground, a heat pump - which works similarly to a refrigerator - removes and intensifies the heat to warm a building. In summer, the pump transfers the building's heat underground.

Most wells for heat-exchange systems are about 300 feet deep; drillers install a field of them to get the right amount of exchange.

But this doesn't work in most urban settings; the Friends Center didn't have enough space. So they're drilling more than a quarter-mile down, through solid Wissahickon schist.

Each hole will be six inches in diameter with a four-inch inner pipe - a "straw" - stuck into it. A pump near the top will suck water up and into the building; then it will flow back into the ground in the space outside the straw.

Although still not complete, the Friends Center project - the first of its kind in the region - has piqued the curiosity of architects and environmentalists.

"If it can be done, it can be replicated," said Dennis Maloskey, a sustainability expert with the Governor's Green Government Council.

Patrick Starr, regional vice president of the Pennsylvania Environmental Council, said: "We need those innovators who are prepared to pay the extra costs for the longer-term benefits."

The federal energy and environmental protection agencies began pushing geothermal heat exchange in the 1990s, saying it was the most energy-efficient and cost-effective heating and cooling technology available.

Lew Pratsch, who ran the Department of Energy's geothermal heat-pump program at the time and now manages the department's Zero Energy Homes project, is still a geothermal-energy proponent.

Around the Philadelphia region, some earlier geothermal installations have been at educational institutions - with land for multiple wells and long-term ownership of their buildings, they could justify the initial outlay.

In 1994, Richard Stockton College of New Jersey, in Atlantic County, began operating its system of 400 wells, each about 425 feet deep. It heats and cools the entire complex.

It also became a showcase for educational and institutional use, says Stockton physics professor Lynn Stiles.

Dozens of school districts in the region now rely on geothermal heat pumps.

Radnor has geothermal systems in three of its schools - despite operations director Leo Bernabei's reluctance seven years ago to ditch the boiler systems he knew so well.

"I've got to tell you, I'm a convert," he says now. And he's proud that savings have mounted: "We are stewards of the taxpayers' dollars."

For similar reasons, other institutions began to adopt geothermal, or even retrofit for it.

Just months ago, Camp Hill Village Kimberton Hills in Chester County finished a system of four wells, each 250 feet deep, to heat and cool the cafe of the community, which serves adults with developmental disabilities.

For the 4,000-square-foot space, it cost $55,000, about $20,000 more than a propane heating system. But a projected annual energy savings of $2,498 and a payback of eight years is expected.

"After that, the system is free," said executive director Deidre Heitzman.

Residential geothermal heat-pump systems actually account for two-thirds of the current U.S. total. In 2007, one in 83 new single-family homes were built with geothermal, said ClimateMaster's Ellis.

Thomas J. Tuffey's townhouse at Hershey's Mill, Chester County, has had it for 10 years.

"Amongst the choir, we're past the tipping point," said Tuffey, an energy expert with Citizens for Pennsylvania's Future. "People that are in the know, if they're building, they're using geothermal."

In Center City, the Friends Center's geothermal system is part of a green makeover that includes solar panels, a vegetated roof, and rainwater holding tanks to flush the toilets.

A tungsten carbide bit will keep drilling wells through early May. It takes about a week per well. The system is to begin operating in late summer.

As McBee surveyed the site recently, she turned philosophical. She thinks nonprofits - especially a Quaker group such as hers - have a responsibility to take the risks of new technologies.

"It's a moral obligation," she said, "as well as a fiscal advantage."