Geothermal is the most energy efficient, environmentally clean and cost-effective space conditioning system available, according to the Environmental Protection Agency (EPA).
The EPA found that geothermal heat pumps can reduce energy consumption and corresponding emissions by over 40% compared to air source heat pumps and by over 70% compared to electric resistance heating with standard air-conditioning equipment. Combining geothermal with other energy efficient measures such as window tinting or replacement, lighting or insulation upgrades can increase these savings even further.
Geothermal heat pumps use the Earth’s energy storage capabilities to heat and cool buildings, and to provide hot water. The earth is a huge energy storage device that absorbs 47% of the sun’s energy more that 500 times more energy than mankind need every year in the form of clean, renewable energy. Geothermal heat pumps take this heat during the heating season at an efficiency approaching or exceeding 400% and return it during the cooling season.
The EPA found that, even on a source fuel basis accounting for ALL losses in the fuel cycle including electricity generation at power plants Geothermal systems are much more effective than competing fuel technologies. They are an average of 48% more efficient than the best gas furnaces. In fact, today’s best geothermal systems outperform the best gas technology, gas heat pumps, by an average of 36% in heating mode and 43% in cooling mode.
The U.S. General Accounting Office estimates that if geothermal heat pumps were installed nationwide, they would save several billion dollars annually in energy costs and substantially educe pollution.
Surveys by utilities indicate a higher level of consumer satisfaction for geothermal heat pumps than for conventional systems. Polls consistently show that mote than 95% of all geothermal heating and cooling customers would recommend geothermal to a family member or friend.
Geothermal heat pumps represent a savings to building owners of 30 to 70% in the heating mode and 20 to 50% in the cooling mode compared to conventional systems.
According to the Geothermal Heat Pump Consortium (GHPC), there goal of 400,000 annual geothermal system installations each year by 2001 will reduce U.S. greenhouse emissions by over 1 million metric tons of carbon each year relative to base case market projections. The reduction in carbon emissions is equivalent to taking over half a million cars off the road, or planting over a million acres of trees. After GHPC’s program ends at that time, a self-substantiating geothermal industry will cause U.S. carbon emissions to decrease by an additional 450,000 tons every year. That translates into a total annual carbon reduction of at least 5 million metric tons by the year 2010.
Achieving GHPC’s goal of 400,000 installations per year by 2001 will save consumers over $420 million per year in energy bills. After that, annual energy savings will increase by an additional $170 million every year.
The biggest benefit of Geothermal Heat Pumps is that they use 25-50% less electricity than conventional heating or cooling systems. This translates into a Geothermal Heat Pump using one unit of electricity to move three units of heat from the earth. According to a report by Oak Ridge National Laboratory, statistically valid findings show that the 4,003-unit Geothermal Heat Pump retrofit project at Fort Polk, Louisiana, will save 25.8 million kilowatt-hours (kWh) in a typical meteorological year, or 32.5% of the pre-retrofit whole-community electrical consumption. This translates to an average annual savings of 6,445 kWh per housing unit. In addition, 100% of the whole-community natural gas previously used for space conditioning and water heating (260,000 therms) will be saved. In housing units that were all electric in the pre-retrofit period, the Geothermal Heat Pumps were found to save about 42% of the pre-retrofit electrical consumption for heating, cooling, and water heating.
Unlike any other heating and cooling system, a geothermal heat pump can provide free hot water. A device called a "Desuperheater transfers excess heat from the heat pump's compressor to the hot water tank. In the summer, hot water is provided free; in the winter, water-heating costs are cut roughly in half.
While producing lower heating bills, geothermal heat pumps are quieter than conventional systems and improve humidity control. These features help explain why customer surveys regularly show high levels of user satisfaction, usually well over 90 percent.
Geothermal heat pump systems allow for design flexibility and can be installed in both new and retrofit situations. Because the hardware requires less space than that needed by conventional HVAC systems, the equipment rooms can be greatly scaled down in size, freeing space for productive use. And, geothermal heat pump systems usually use the existing ductwork in the building and provide simultaneous heating and cooling without the need for a four-pipe system.
Architects and building owners like the design flexibility offered by Geothermal Heat Pumps. Historic buildings like the Oklahoma State Capital and some Williamsburg structures use Geothermal Heat Pumps because they are easy to use in retrofit situations and easy to conceal, as they don't require cooling towers. Geothermal Heat Pump systems eliminate conventional rooftop equipment, allowing for more aesthetically pleasing architectural designs and rooflines. The lack of roof top penetrations also means less potential for leaks and on-going maintenance, and better roof warranties. In addition, the aboveground components of a Geothermal Heat Pumpm system are inside the building, sheltering the equipment both from weather-related damage and potential vandalism.
Because a Geothermal Heat Pump system is so efficient, it uses a lot less energy to maintain comfortable indoor temperatures. This means that less energy often created from burning fossil fuels is needed to operate a Geothermal Heat Pump. According to the EPA, geothermal heat pumps can reduce energy consumption and corresponding emissions up to 44% compared to air-source heat pumps and up to 72% compared to electric resistance heating with standard air-conditioning equipment.
According to a study completed for the Geothermal Heat Pump Consortium (GHPC), buildings with Geothermal Heat Pump systems had average total maintenance costs ranging from 6 to 11 cents per square foot, or about one-third that of conventional systems. Because the workhorse part of the system the piping is underground or underwater, there is little maintenance required. Occasional cleaning of the heat exchanger coils and regularly changing the air filters are about all the work necessary