Geothermal systems are a renewable and sustainable source of reliable energy. The system doesn't burn fuel therefore safeguarding clean air and uses little land therefore there is less of an impact on the environment. With more and more geothermal systems in place there is less of a need to use fossil fuels which makes these systems much more suitable for our needs and the environments needs.
The benefit of a geothermal system is that it has predictable costs with no surprise price increases. Homeowners can see savings range from 25% to 50% over the year on their heating costs.
2 Common geothermal systems
A closed loop system, which is the most common, circulates water through the pipes in the loop field and the heat is transferred across the pipe. There is no interaction with the circulating fluid and the ground. The amount of loop required for any given system can be determined by a conductivity test. This test will determine the amount of heat being absorbed and rejected by the ground over the course of the year.
A vertical closed loop field is a series of vertically drilled boreholes typically 150 to 300 feet deep with a pair of pipes connected at the bottom with a U-bend to form the geothermal loop. Each borehole is then grouted with a bentonite grout to form a thermal connection to the surrounding soil. Each loop is then connected in series to create a reverse return header which can then be piped to the mechanical room. Vertical loop fields are generally used when there is limited amount of land available.
A horizontal closed loop field is composed of pipe installed horizontally into a series of trenches to form the loop field. These trenches are typically excavated by machines and are dug to depths from 4 to 6 feet to avoid frost. These loop fields can be used when there is adequate land available.
A closed pond loop is not as common, but is just as useful. A pond loop is composed of pipe sunk into an appropriately sized water source. The pipe is attached to a frame and then sunk to the bottom of the water source. It is similar to the horizontal ground loop with the exception of being coiled much closer together than the horizontal loop field.
How the system works
The geothermal system is a heating and/or air conditioning system that uses the earth's ability to store heat in the ground and water. The temperature in the ground is stable year round and the heat pumps use this to; in the winter, extract the heat and in the summer puts the heat back into the ground. Depending on locations annual climate the ground heat can range from 50 - 85 F (10 - 30 C). The geothermal system differs from a conventional heating system by its ability to transfer heat versus the standard method of producing heat. As energy costs rise and pollution becomes more of a concern the geothermal system may become a solution to both of these concerns.
The benefits of using geothermal systems from an environmental standpoint is the fact that geothermal systems are the most energy-efficient, environmentally clean, and cost effective space conditioning systems available. Most loop fields are warranted for 25 to 50 years and are expected to last 50 to 150 years. This makes these systems longer lasting than conventional heating systems. Geothermal systems don't use fossil fuels for heating which eliminates the chances of carbon monoxide poisoning.
Geothermal technology has resulted in emissions reductions, more than 5.8 million metric tons of carbon dioxide annually. Currently for the amount of geothermal systems up and operating it is equivalent to taking 1.3 million cars off the road, planting 385 million trees, and reducing the dependency on importing crude oil.