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Geothermal
pumps use earth's energy to heat, cool buildings
by
Katharine Webster (AP)
LACONIA,
N.H. -- The guests at Maurice and Helene Gouin's bed and
breakfast, Rest Assured, come to swim and fish in Lake Winnisquam, cruise in
Gouin's solar-powered launch, or simply gaze across the water
as they eat blueberry pancakes with homemade maple syrup.
But
Lake Winnisquam is more than just a beautiful view and a
refreshing dip for the guests at Rest Assured. It also
provides the energy that heats and cools the three-story,
4,800-square-foot house on the lake's edge.
From
the second-story porch off the kitchen, Gouin points out the
white-painted logs that hold down a 1,500-foot loop of plastic
pipe on the lake bottom. Water mixed with antifreeze runs
through the loop and back into a geothermal heat pump in Gouin's basement. The heat pump exploits the temperature
difference between the lake water and a refrigerant gas to
heat Rest Assured to 70 degrees in winter, cool it to 72
degrees in summer and supply two-thirds of its hot water. The
cost is about $700 a year in electricity, a bargain by any
measure. "It's nothing but a refrigerator,
basically," Gouin explains. "When you put food in
the refrigerator, you take heat out of the food and dump it in
a coil in the back of the refrigerator. This is just a bigger
unit."
Geothermal systems -- a heat pump connected to
piping buried in the ground, laid on a pond bottom or run down
a well -- are taking off, thanks to a push by the government
and electric utilities. A 1993 study by the U.S. Environmental
Protection Agency found that geothermal systems are the most
energy-efficient, least- polluting space conditioning
technology available today in most of the country. Heat pumps
cost up to two-thirds less to operate than electric baseboard
heat or conventional fossil fuel furnaces and hot water
heaters. The savings are smaller but significant on air
conditioning. An electric-powered heat pump uses only
one-third as much power as electric baseboard heating and
conventional air conditioning, meaning it is responsible for
only one-third the carbon dioxide, sulfur dioxide and nitrogen
oxide emissions. The coolant in the pipes meets new EPA
standards banning chlorofluorocarbons that can destroy the
ozone layer. Heat pumps also generally are safer, steadier,
quieter and less obtrusive than conventional systems, their
advocates say.
So why aren't they more popular? Mostly it's a
matter of getting the word out, said Paul Liepe, executive
director of the Geothermal Heat Pump Consortium, a public-
private group formed in 1994. "It's an extremely
well-kept secret that we don't want to keep," Liepe said.
The consortium is hoping to increase the annual number of
geothermal installations from 40,000 to 400,000 by 2000, by
teaching builders how to install them and educating mortgage
lenders about their advantages. Although the basic technology
has been around since the 1940s, it is only in the last 10 or
15 years that it has become extremely reliable and adaptable
to almost any climate or site, Liepe said. Because the earth
maintains a constant, year-round temperature only 7 feet below
the surface, it acts as a heat source in winter and a heat
sink in summer. The free energy is extracted and transferred
by the heat pump, which can be powered by electricity or
natural gas.
The biggest barrier for many homeowners is a lack
of understanding about geothermal systems and a shortage of
builders who know how to install them, said Carl Orio,
president of Water and Energy Systems in Atkinson, a
distributor and designer of geothermal systems. Also,
geothermal systems can cost about $4,000 to $5,000 more to
install than conventional systems because the homeowner must
drill wells or dig a trench to bury the pipe loop, Orio said.
The cost goes down if the homeowner can use one well for
drinking water and a geothermal system, Orio said. Some
utilities subsidize geothermal installations. Even without
subsidies, geothermal systems typically pay for themselves in
about three years, Orio said. Over 10 years -- even with a
higher monthly mortgage payment for the installation --
someone in an energy- efficient, 2,000-square-foot home in
southern New Hampshire would save nearly $13,000 compared to a
homeowner with a propane furnace and hot water heater, he
said. The savings are lower and may not offset the higher
installation cost in areas where the climate is mild or energy
costs are low, said Kevin Rafferty, associate director of the
Geo-Heat Center at the Oregon Institute of Technology in
Klamath Falls.
For commercial buildings, however, the
installation costs for geo- thermal heating systems often are
the same or lower than for conventional heating and cooling,
Liepe said. When the Manheim Township School District in
Lancaster County, Pa., renovated and expanded the Neff
Elementary School, the geothermal system cost $13.69 per
square foot to install -- less than conventional systems at
the Reidenbough Elementary School built four years earlier.
Annual heating and cooling costs at Neff run about 75 cents
per square foot, compared to about $1.16 at Reidenbough, Liepe
said.
The U.S. Army found similar savings when it used
geothermal cooling and heating for 4,003 new family housing
units at Fort Polk, La. This spring, two 1,500-foot-deep wells
were drilled into the bedrock under New York City for
Foundation House, a new building being put up in Manhattan by
labor lawyer and philanthropist Theodore Kheel. The wells will
be the heart of a geothermal system designed by Orio.
Electric
utilities like geothermal systems because they operate more
steadily than furnaces and air conditioners. That reduces the
peaks and valleys of demand for electricity and allows power
plants to run more efficiently, said Mike McQueenie of Public
Service Co. of New Hampshire. Electric-powered systems also
mean new customers in areas where people traditionally heat
with oil, natural gas, or propane, so many electric utilities
offer incentives to cover installation costs and lower
electric rates, McQueenie said.
When Gouin, a plumbing and
building contractor, built Rest Assured in 1986, he spent an
extra $10,000 to install a heat pump. His plumbing friends
said he was nuts. When he tried to peddle geothermal systems
locally, he had few takers. Now he looks like a visionary. Two
heat pump manufacturers are courting him as a potential
distributor and installer, Gouin said, and local interest is
picking up. "I have friends that are smarter than me. I'm
just the crazy one who will try it. I'm just a tinkerer -- I
have to have answers," he said. And the answer is?
"Get all of your heat from under your feet."
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