The Earth produces a certain amount of heat. We call this geothermal energy. In the ground for the first 3 meters, the temperature of Earth keeps a constant temperature of between 10 to 16 degrees Celsius. With the use of modern technology such as geothermal heat pumps we now have the ability to use this energy to both cool and heat buildings. At a depth of about 6 ½ km beneath the surface of the Earth, there are hot dry rock resources. Using a process that allows water to go over the hot rocks allows the heated water to then be extracted elsewhere.
A power plant can use steam to generate electricity. The steam causes a turbine to rotate and that, in turn, activates the generator that then produces the electricity. To produce the steam a significant amount of power plants use fossil fuels. Steam can be produced, however, with geothermal energy. There are reservoirs of already heated water found a few kilometers below the Earth’s surface.
A power plant that uses dry steam can get this from steam found underground. It can be piped into wells and from there to the power plant where it will power a generator. There are reservoirs where the temperature is at 182 C. This water actually gets to the surface by itself. As it comes up some of the pressure is released and this causes some of the water to turn to steam. This steam can then be used to power the generator. This is considered to be a sustainable form of energy.
There’s also another type of power plant that uses water that stays between 107 to 182 C. The plant uses the hot water in combination with a fluid that can boil at lower temperatures. This fluid then vaporizes which creates the energy needed to turn a turbine. The remaining water is injected back into the Earth and is naturally reheated. During the whole process that fluid and water are always separate. This means it doesn’t create any type of emissions.
Geothermal use has been something used throughout history. Natural hot springs were used for bathing, for removing skin and feathers from wild game, and even for cooking food. In the modern era, they are used as spas. As technology has improved, these resources of geothermal energy are being used in new ways to produce energy.
Direct use systems pull from reservoirs of hot water to produce energy. The water is mechanically piped to a heat exchanger that uses the heat for whatever use it’s intended for. There are many uses that the naturally occurring hot water can be used for. Currently, it is commonly used to heat buildings of different sizes. It’s also used for fish farms and for pasteurising milk. Research and advancements in technology are increasing the ability to use this as a way to produce electricity.
Geothermal Heat Pumps
As technology grows the ability to use the Earth’s sustainable energy sources is increasing. One of the important ways in which geothermal energy is being utilised is with the use of special heat pumps. These types of geothermal heat pumps have three different parts. There is the air delivery system, the unit itself, and a heat exchanger. A series of pipes are buried at depths that are relatively shallow in the ground and located fairly near the building that it will produce energy for. A mix of antifreeze and water will pass through the pipes and will consequently be heated up from the ground. In the summertime, the pumps take heat from inside the building and remove it using the heat exchanger. In winter it pumps the heat into the building. When the heat is being removed during the summer time it can be used to make hot water which means there’s no added cost for heating the water in the building.
These special heat pumps use considerably less energy than other typical systems for heating a building. They are also more efficient when it comes to cooling a building. This helps to reduce air pollution which is better for the Earth and it saves money and energy.
The Future of Geothermal Technology
As scientists are trying to fully understand what is happening with global warming and the other issues surrounding the use of fossil fuels they are looking for renewable sources of energy that do not damage the Earth’s atmosphere. Geothermal energy is one of the renewable sources of energy that accomplishes that goal. They are still struggling to find more commercial ways of using this energy but there’s no question that in time they will find how to maximise the use of this reusable source.
As the technology advances it also means that as well as giving us all a source of energy for electricity as well as heating and cooling, it will also mean that it will give a boost to the economy as the technology will open doors for more jobs related to the industry. Renewable energy is already employing tens of thousands of people and it will continue to grow. Part of what is driving all of this is climate change.