Stimulus Money – Geothermal Energy
Geothermal energy is usually associated with the western states and Yellowstone National Park or “The Geysers” field in Northern California. However, geothermal energy can be utilized just about anywhere in the US and is economical when employed in residential applications in the Northeast. Homeowners who install a qualified geothermal heat pump system in 2009 and later years are eligible for a provision in the Stimulus Bill allocating a 30% tax credit applied to the purchase price of a new system. A credit of 10% of the total investment is also available (no maximum) for a commercial system installation.
The system’s basic concept takes advantage of the earth’s constant temperature, approximately 55 degrees, to heat and cool a building. By tapping this steady flow of heat from the earth in the winter, and displacing heat in the earth in the summer, a geothermal heat pump can save homeowners 40 to 70 percent in heating costs and 30 to 50 percent in cooling costs compared to conventional systems.
Ground source heat pumps (GSHPs) work in a similar manner as air source heat pumps, minus the higher operating cost. A typical household can save on average $1,500 a year resulting in a payback period of three to five years. GSHP’s are more than three times as efficient as the most efficient fuel furnace. By moving heat that already exists in the earth, instead of burning a combustible fuel, GSHP’s deliver three units of energy for every one unit used to power the heat-pump system.
Ground source heat pumps work by circulating water or an antifreeze solution through a closed loop of polyethylene pipe that is buried in the ground or set in a body of water. A closed loop system, the most popular, can be laid out either vertically in 50-250 foot deep holes drilled like a well, or horizontally in 3-6 foot deep trenches. The less common open loop system circulates a constant source of ground water and dispels the water back to its origin, such as a stream, well, or pond.
The principle action of a heat pump moves heat from lower temperature location to a higher temperature location. A ground source heat pump works in a similar manner, except that its heat source is the warmth of the earth. The process of elevating low-temperature heat to over 100 degrees F and transferring it indoors involves a cycle of evaporation, compression, condensation and expansion. A refrigerant is used as a heat-transfer medium which circulates within the heat pump.
The ductwork is no different than that of a conventional forced-air system. The difference is found in the temperature of the air flowing from the registers in the winter. With a conventional air source heat pump, the air flow is seldom warmer than 80 degrees. But because water transfers a greater volume of heat than air, the GSHP is able to deliver warmer air, typically about 110 degrees F.
Another benefit of a ground source heat pump is utilizing a desuperheater. This component transfers residual heat from the compressor to water. In the summer, when the system is working to get rid of heat, the desuperheater can provide practically free hot water. And since most systems are oversized, there is usually enough warmth left over for low cost hot water in the winter too.
While GSHPs require a small amount of electricity to concentrate the energy and circulate it through the system, most systems derive approximately 70 percent of their energy from a renewable source — the earth. GSHPs do not require a flue, and since there is no on-site combustion, there’s less chance of fire, and no chance of carbon monoxide infiltrating the home. GSHPs also carry the Environmental Protection Agency’s Energy Star Label, which is used to designate energy-efficient equipment. Often homeowners may find tax benefits, lower mortgages, or utility rebates.
For more information on Venture Engineering’s geothermal systems, please contact Travis Buggey at (412) 231 — 5890 x 325.