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PrintTapping Earth's Energy
As fuel costs skyrocket, consumers drill for savings
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A decade ago, when Stephen and Nancy Shibuya were heating their house with a wood-pellet stove, Nancy attended a Jackson home-and-building show. There she found out about an alternative means of heating that sounded not only like less work, but also more friendly to the environment.
Despite having just learned of the technology, called geothermal or ground-source heating, the couple decided to install a system when they remodeled their modest home near Game Creek, south of Jackson. The Shibuyas were attracted to the idea of not having to haul wood pellets, to the potential comfort of a more evenly dispersed heat, and to the promise of cheaper utility bills.
“It seemed like it was a reasonable thing to do,” Stephen said.
But the retrofit didn’t come cheap. Their heat-pump system, which utilizes thermal energy from the earth, required the Shibuyas to drill four 180-foot deep holes to install tubing to capture that energy.
Such drilling can cost thousands of dollars, according to Wid Ritchie of Lower Valley Energy (LVE), which provides power to Jackson Hole and, to the south, Star Valley. Ritchie, who said he hasn’t seen a geothermal heat pump installed for less than $20,000, oversees the energy cooperative’s rebate program, which rewards homeowners for purchasing and installing energy-saving devices like ground-source heat pumps. Depending on how a system was constructed, Ritchie said, LVE has paid homeowners rebates of up to $3,500 for installing geothermal heat pumps.
Compared to conventional systems, however, according to the U.S. Environmental Protection Agency (EPA), such a setup can cut heating costs up to 70 percent and, come summer, cooling costs by as much as 50 percent.
Ironically, thinking about future savings has homeowners turning to what is actually an old technology. According to the International Ground Source Heat Pump Association, headquartered at Oklahoma State University, Lord Kelvin developed the concept of the heat pump in the middle of the nineteenth century. Heat pumps use water, an antifreeze solution, or a refrigerant to absorb and radiate heat, transferring it from outside to inside in winter and from inside to outside in summer. Heat pumps have been used for years to heat and/or cool many commercial buildings, from grocery stores to schools. And, counter-intuitive though it may sound, common cooling appliances like refrigerators and air conditioners are applications of the heat-pump principle.
Ground-source heat pumps differ from conventional heat pumps in that they take advantage of the ultimate solar collector: the earth. These systems perform the work that typically requires a pair of separate appliances, a furnace and an air conditioner. And sometimes even a third: Many manufacturers today are offering triple-duty setups, which provide heat, air conditioning, and hot water.
These systems utilize a series of pipes, called a loop, installed either vertically or horizontally beneath the ground surface, where temperatures are more stable—in our region, averaging around fifty degrees Fahrenheit. A water or antifreeze solution is then circulated through the loop to absorb the earth’s natural warmth. The heat pump concentrates the captured thermal energy, brings it up to the desired temperature, and then pushes heated air through the interior ductwork of a home or building.
In summer, the opposite occurs, with the system extracting hot air from inside a house and transferring the heat to the earth. Some hot air may also be diverted to heat water. This can reduce water-heating bills by as much as 30 percent, according to the Geothermal Heat Pump Consortium, a non-profit created in cooperation with the EPA in 1994 to tout the technology.
Despite promises of savings and rebates, ground-source heat pumps have just begun to catch on in the Tetons. LVE records in 2006 showed that only five installations had generated rebates since 2004. Ritchie attributed the limited interest to the costly up-front investment.
Stephen Shibuya, who installed his system prior to the rebate program’s launch, agrees the initial costs can be a deterrent. “It was a lot more than putting in baseboard heat,” he said.
But that could be changing, according to Toby Schmidt, an owner of Creative Energies, a renewable-energy company based in Lander, Wyoming, and with an office in Teton Valley, Idaho. He said geothermal heat pumps are beginning to spawn more interest in the region as homeowners hunt for ways to combat soaring energy bills.
“I think our business has almost doubled this year,” Schmidt said. He credits the growing interest in renewable-energy sources like geothermal to the rising cost of fossil fuels.
Some local customers desire first and foremost to lessen their impact on the environment. Others are more focused on the bottom line, Schmidt said. People constructing new homes, in particular, are wary of building a house they might not be able to afford to heat.
“People are worried about what the prices are going to be,” he said. “They’re thinking about the future.”
Homeowners with a stream or pond on their property can run surface water through an “open loop,” achieving the desired heating or cooling before returning the water to its source, Schmidt says. Other systems rely on well water, and some closed loops utilize an antifreeze solution. The antifreeze is needed in some instances because the system extracts so much heat from the liquid that pure water could freeze in the winter.
A growing number of school districts are turning to the systems, too. Nationally, schools are reaping $25 million yearly in energy savings, according to the geothermal consortium. In Wyoming, a geothermal heat pump warms and cools the Wilson school where Nancy Shibuya teaches, and the Bighorn School District hired Creative Energies to install a system in the new Greybull Elementary School. It’s one step in a comprehensive effort to make school buildings in the state more energy efficient.
Also dubbed geoexchange, the systems can not only lower heating bills, but also decrease greenhouse gas emissions and reduce the nation’s dependence on fossil fuels. According to statistics provided by the geothermal consortium, for every 100,000 homes using the pumps, the nation cuts consumption of foreign oil by 2.15 million barrels per year and trims annual electricity consumption by 799 million kilowatt hours.
Still, not everyone is a fan.
“As far as heating goes, no place in Wyoming that I know of is really an optimum place for ground-source heat pumps,” said Chuck Hunt, owner of Pinedale-based Bridger Mechanical. Hunt’s former business partner, who has since retired, installed the Shibuyas’ system, but Hunt has no plans to
continue offering the geoexchange technology. He believes Wyoming’s ground and groundwater temperatures are too cool for the systems to run efficiently. Moreover, improved efficiencies in more traditional heating solutions, such as boilers and furnaces, just don’t make the increased investment in geoexchange worth it, he said.
