Geo-Thermal Energy Systems
by Carol Lee
Fall is approaching. Soon, the leaves will flash colors like sunflowers, marigolds and roses, then turn brown, and fall into huge bunches and loud crunches under our feet. Before the air even begins to chill, the oil companies will send out new contracts for a winter's worth of oil, prepaid, at a reduced price. Hopefully.
As our government has a greater investment in oil than in alternative energy, what can we as homeowners do to cut our costs of heating and cooling? In a time of war and surging oil prices, limited water and other natural resources, how can we preserve the environment and maintain our precious resources?
One way may be to build new homes incorporating energy and water efficient systems, to enhance quality of life in the home and on the planet. One such technology is geothermal heating and cooling. Geothermal exchange systems use water circulating through underground pipes to transfer the heat from the ground into buildings in winter and out of buildings in summer. All geothermal systems are hot air systems, as opposed to liquid or solid systems.
The average daily temperature in the mid-Hudson in January and February is 26 degrees; in July and August it is 72 degrees. Yet just six feet below the ground surface the temperature of our planet is approximately 55 degrees. By tapping this steady flow of heat from the earth, a geothermal heat pump can save homeowners a good percentage in heating and cooling costs compared to conventional systems. It also heats water at minimum cost in the summer, and lowers the cost during the winter by about half.
Most people don't know about it today, but ten thousand years ago, Indians in America used geothermal energy--hot springs--for bathing and cooking. The Romans used it two thousand years ago, in Pompeii, piping hot water under their homes for heating. Today we have the technology to harness this energy, yet there are only about 150,000 units installed in homes in the United States.
Also known as "ground source heat pumps," geothermal heating and cooling has been deemed "the most energy-efficient and environmentally sensitive of all space conditioning systems," by the Environmental Protection Agency. It uses no combustible fuel or on-site fuel storage tanks.
Right in our own backyard, at Bard College, are prime examples of this technology. Perhaps as spectacular as its undulating roofs, incomparable sound system and seats of varying widths, the new Richard B. Fisher Performing Arts Center designed by Frank Gehry, is also a marvel of energy efficiency, thanks primarily to Dick Griffiths, Bard's now-retired director of buildings.
Griffiths, worked at Bard for over 42 years, retrofitted his first electrically-heated and cooled dormitory with geothermal energy fourteen years ago. Since then he has since retrofitted six more. So committed is he to this new technology that he has not installed a heat tank on campus in over six years! The engineers who actually built the Fisher Center needed to be educated about the process, so Griffiths brought in the Geothermal Consortium from Washington, DC to sit in on job meetings.
Engineers drilled 180 dry wells for the Fisher Center, each 400 feet deep and six to seven inches in diameter. An equivalently long double length of very rigid 1-1/4 inch pipe with a U-turn at one end was inserted down into the well. Water circulates down to the bottom, where it picks up the earth's steady 55 degrees, then makes a U-turn back up and into the building. (The wells are dried by pumping all the water out and then filling them not only with the pipe but with solid grout to grout in the pipe.) The pipe comes into the building five feet below the surface of the ground, to prevent freezing. During cold weather, water is pumped down through the pipe, where it picks up the warm temperature of the earth and returns back up the pipe at 55 degrees. Then it is run through a coil and a compressor which compresses the heat up to 120 degrees.
This compressor is similar to one in a refrigerator, increasing or lowering the temperature as needed. It runs on electricity. The heat (or cold) is blown into the building through the air handler (radiator register). Thermostats throughout the building let you regulate the temperature. As the system is sealed, the same water is circulated through the pipes, saving on this natural resource, as well. It is important to remember, however, that the system does require electricity to run the compressor and the blowers.
To cool the building, the process is reversed, by pumping the warm water down the well, where it comes back up at 55 degrees. The compressor takes it down to 30-35 degrees, then that air is blown through the building and cools it to about 72 degrees.
Griffiths recently designed and built his own house, digging only two wells for geothermal heat: "Just last January and February--the two coldest months--it cost me only $200 each month for my utilities!" And, he adds, "there's no fumes, it's clean heat with very little service required. I do have to change air filters in the air ducts in the building. And the heat pumps can be scattered through the building, where they do the most good."
He can almost prove now that drilling the wells, and installing the system doesn't cost much more than conventional systems. "You don't need a chimney, furnace, gas or oil tank, or large utility room, and the ductwork inside the building is the same, but the drilling and compressors are extra." He estimates that it takes three to four years to recoup the extra cost, "if any. . ." and that amount of time descends as oil prices go up." Griffiths, who is currently overseeing the construction of the new science building at Bard College, offers geothermal seminars locally.
Barbara Schutzman is another advocate of geothermal systems. In 1989, she bought an electrically-heated home in Rhinebeck. She wanted to change the system and add air conditioning as well. At the time, the electric companies offered rebates to homeowners who installed more energy efficient systems. This incentive propelled her to adopt geothermal energy: "No noisy, unsightly AC unit sitting outside; no fossil fuel use, and a very even distribution of heat." And, since there is no onsite combustion (furnace), there's less chance of fire, and no chance of carbon monoxide infiltrating the home. The systems are quiet and compact, with all the equipment usually fitting neatly into one metal cabinet.
"I felt from the beginning the cost was moderate when compared to other heating and cooling systems, and I've never looked back." The cost for drilling the wells, installing the ducts and compressors was $14,000. For oil heat, the cost for a furnace and the ductwork would have been $11,000. The electric company rebate came to $1,800. It was a no-brainer. "Now my bills for all heating and cooling come to $2,100 per year!" Schutzman can't understand why you don't hear more about geothermal energy --its merits and incentives--today. Maybe it's because there are no great rebates being offered to residential customers. Unfortunately, this year, Central Hudson no longer offers rebates to residential customers seeking more cost-efficient energy. (Last year they offered $200.) They will revisit that program next year, but unless they make a sizeable rebate offer, much like the one Ms. Schutzman received, the payback on the installation of a geothermal system might take closer to ten years to recoup than three to five.
According to Jessica Barry, Outreach Coordinator for Mid-Hudson Energy $mart Community, this year NYSERDA offers rebates to commercial customers. But NYSERDA will buy down the interest rate on a loan by 4 percentage points (4%) for both residential and commercial customers installing geothermal systems. They make loans up to $20,000. through participating banks
The Geothermal Heat Pump Consortium (which includes the EPA, the Department of Energy, 240 electric utilities and 20 heat pump manufacturers) offers incentives that include low-cost loans to homeowners and utility rebates and low cost loans to commercial customers. (Builders, please take note!)
According to a principal of Freedman Fisher, which provides mechanical electrical plumbing, but for commercial properties only, geothermal energy cut its teeth in the residential market, but it is a costly investment, and lends itself best to commercial buildings with multiple thermostats, access to sizeable utility rebates and loan incentives, and residential new construction with air-conditioning, where you'd already have a drill rig for a well on site.
John Maserjian, marketing director at Central Hudson, says the cost of installing geothermal sytems, "is comparable to high-end conventional systems with air-conditioning. . . . very efficient." For oil heat, it costs 89 cents per square foot to heat a 1,200 sq ft home (based on this year's prepaid contract, which is 30 cents higher per gallon than last year's) and 58 cents per square foot to heat and cool a 1,200 sq ft home with geothermal energy
So, am I ready for a geothermal heat pump? Well, as oil becomes more expensive, or if I build a new home with air conditioning and incentives become attractive--I'll look into it. Is it right for you? You can probably learn all you could want to know by writing, phoning, or going to the websites of one of the following organizations.
Resources
• For local information, Mid-Hudson Energy $mart Community: 845 331-2238.
• For the Geothermal Heat Pump Consortium call or write: 701 Pennsylvania Ave. NW, Washington, DC 20004. Phone (202) 508-5500 or (888) 333-4472. Website: www.geoexchange.org
• For the US Environmental Protection Agency, Residential Efficiency Programs. Mail or call 401 M Street SW, Washington, DC 20460. Phone (202) 233-9127. Website: www.energystar.gov/.
• For a low-interest loan for cost-saving, energy-efficiency improvements write or call: NY State Energy Research and Development Authority (NYSERDA), 17 Columbia Circle, Albany, New York 12203-6399. Phone (518) 862-1090 or toll-free at 1-866-NYSERDA. For a low-interest loan or for cost-saving, energy-efficiency improvements visit: www.nyserda.org/602pon.html
• Other websites: www.awesomesonsolar.com/geotfaq.htm
www.reddawn.com/featart11-98.html
www.eere.energy.gov/consumerinfo/heatcool.html
