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 Citizen News
April 2009 Geothermal Home Heating
The reality that we can dig down in the earth and draw on its underground warmth to heat our homes so captivates my imagination that one night I dreamt about this. I was looking down from outer space and saw that the earth was peppered with holes because millions of households had gone geothermal, and I awoke with the awful thought that with so many deep holes, the earth might lose its inner warmth. I even phoned a scientist friend, who reassured me it wouldn’t happen, at least not any time soon, and we chuckled over my dream.
Let’s come down to earth and to the facts. Today’s geothermal systems most often involve digging either horizontal trenches about 4 ft. deep or one or more vertical holes of 225-450 ft., into or down which highly durable plastic piping is placed that connects to a geothermal unit (heat pump) in your home. The pipes contain water with a non-toxic anti-freeze that absorbs heat from the surrounding earth and rock, and circulates the heated water into the unit, which converts it to warm air that heats the house and, if you so choose, also heats water for household use.
Because of Connecticut’s geological characteristics, it is usually easier h ere to go vertical than horizontal – ledge rock is actually an advantage in that it prevents deep holes from collapsing. Going horizontal uses more land that cannot be planted over with trees and bushes, lest their roots damage the underground pipes.
The geothermal unit runs on electricity, but if your electricity provider draws partly or wholly from renewable sources of solar, wind or water power, there is very little or no carbon footprint. Properly installed, the system needs hardly any maintenance, only changing the furnace filters every few months.
Brian and Heather Williamson of Sherman built a new Energy Star Certified house with geothermal heating including the option for domestic household hot water and radiant heat, complemented by an indoor air quality system. Now in their sixth year, Brian says they are “incredibly satisfied, in retrospect we would not have done it any differently.”
The Williamsons first became interest ed in geothermal technology during a visit to Northeast Utilities Smart Living Center. Brian explains the factors for selecting geothermal: “our system is projected to have a much longer life than any combustion furnace. Northeast Utilities said our high efficiency geothermal system would reduce our annual heating/cooling costs by at least 50% compared to a traditional combustion furnace with separate air conditioning units. Their engineers estimated that our reduced greenhouse gas emission was the equivalent of taking 3.5 cars off the road.”
In building their house in 2003, the Williamsons qualified for grants from the Connecticut Energy Efficiency Fund, which completely covered the cost of digging the wells and included a rebate on the WaterFurnace pumps. Northeast Utilities estimated their payback and the return on their geothermal investment at 7 years for Sherman, where the heating season is substantial and the Northeast energy and heating costs are much higher.
Their spacious home required 5 vertical wells for 4 geothermal pumps. The house is very well insulated, the temperature is set at 66 for t he night and 70 for daytime. Their house features an open floor plan with minimal interior walls, high ceilings, walls of glass and numerous skylights. Their monthly electric bill now averages about $425 year-round (825 in winter months and 225 in spring, summer and autumn). In 2003 the all-year monthly average was $225, when the inflation adjusted price for a barrel of crude oil on NYMEX was generally under $25/barrel and the cost per kWh of electricity from CL&P was approximately $0.10
Yes, costs are going up and the up-front expense of installing a geothermal system is considerable. A smallish 2000 sq. ft. house being retrofitted for geothermal would probably need only one vertical well, costing between $6000-7000 to drill. The piping, the heat pump and the duct work – if your existing ducts are 20 years or more, you probably need new ones – would bring the total installation cost to somewhere between $23,000-27,000.
The funding for the grants and rebates has dried20up for the time being, but Bill Sequin of Seguin Heating and Air Conditioning in New Milford tells me there is now a 30% tax credit on the total cost of geothermal installation and it is available to everyone, with no income limitation. Moreover, and this is important, the installation cost is not counted as a taxable improvement on your house, so it will not raise your local property tax. As to ongoing costs, Bill estimates that if your fuel oil at $3.50 a gallon runs to $800 monthly in the depths of winter, a geothermal system would save you 50% and it would be 75% when heating oil gets to $4.50 a gallon. Over the years, that becomes a substantial saving.
Geothermal doesn’t suit every house. Some plots are too small – bear in mind the ground installation must be at least 50 ft. from the septic system and the fresh water well. If your present heating system is hot water baseboard, it cannot be adapted to geothermal. Antique houses preserved for their historical value are also not candidates, since geothermal needs good insulation.
Where it does suit, the benefits are multiple. Geothermal energy is renewable, clean, and environmentally friendly, and over time, it saves money. To say, as one industry newsletter does that it “delivers peace of mind,” well that just might be asking too much.
Here area few websites within information about geothermal energy:
www1.eere.energy.gov
apps1.eere.energy.gov
Wikipedia.org
Geothermal.marin.org
Waterfurnace.com
Seguinhvac.com
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