There are two main types of geothermal energy: geothermal electricity and geothermal heat pumps. Geothermal electricity uses heat from deep inside the Earth to turn water into steam, which is then used to generate electricity. The hot water can also be used directly or used to heat a building. Geothermal electricity is feasible only in certain parts of the world where there is geologic activity. The U.S. produces less than 1% of its energy by this method. Countries that generate at least 15% of their electricity this way include Costa Rica, El Salvador, Iceland, Kenya, and the Philippines.
Geothermal heat pumps, also known as ground source heat pumps (GSHPs), can be used almost everywhere in the world for heating and cooling air and for heating water. A GSHP uses the heat in the top layer of the Earth’s crust. This energy comes from the sun and is absorbed by the Earth’s surface, thus the term “ground source heat pump.” GSHPs transfer heat from the ground to the building in colder weather and from the building to the ground in warmer weather. The system typically involves a closed loop of underground pipes containing a liquid that can easily transfer heat.
GSHPs were first described in the 1850s and first developed in the 1940s. In the United States today, they are being used in all 50 states. Traditional air source heat pumps are very efficient and GSHPs are even more efficient due to the underground temperature being more stable throughout the year than air temperatures.
GSHPs are relatively expensive to install, but the costs are generally made up in energy savings within 3-10 years. The various components of the system last anywhere from 25-50 years. In addition to saving money, using geothermal energy instead of fossil fuels reduces carbon dioxide, nitrogen oxide, and sulfur oxide emissions. This can lead to improvements in local air quality and alleviate global atmospheric problems, such as acid rain and climate change.
Madeira students will indeed benefit from having air conditioning in their dorm once the geothermal system is in place. In addition, the Science Department has used the implementation of the new heating and cooling mechanisms as a teaching opportunity that will benefit our girls as they make their own energy decisions in the future.
