Geothermal Energy: Using the Earth's Heat

There are so many cool things about our planet. For example, geothermal energy. Geothermal energy has been used by all sorts of ancient societies and groups, like the Ancient Romans and the Native Americans.

Geothermal energy is a type of renewable resource, meaning that there is enough of it that humans will never run out of it. Now, most people use nonrenewable resources like coal, oil, and natural gas because they are marketed as cheaper and are what most industries use. However, these resources are limited, which means that we will run out of them soon. We will also need to use other resources, which is where renewable resources come in.

The deeper you go into the ground, towards the center of the Earth, the hotter the temperature. This is because the center of the Earth is much hotter than the surface. The heat stored in the ground is geothermal energy. There are two types of ways people can harvest geothermal energy: power plants and heat pumps.

Geothermal power plants pump hot water to Earth’s surface. First, hot water is pumped from deep in the Earth through a well that is under high pressure. When the water reaches the surface, the pressure is suddenly decreased. This causes the water to turn into water vapor. Then, the water vapor spins a turbine, which is connected to a generator that creates electricity. After spinning the turbine, the steam goes to a cooling tower, where it cools off and turns back into water. This cooled water is pumped back into the Earth, and the process begins all over again. Engineers create a system that contains pumps, turbines, generators, and a cooling tower. A geothermal power plant looks something like the picture below.

Geothermal heat pumps work a little differently. They work on a smaller scale; instead of creating energy for hundreds or thousands of people, geothermal heat pumps do things like heating/cooling homes and warming pools. These pumps work by pumping water or special liquids through pipes just below Earth’s surface. During the winter, the pipes absorb heat from the Earth to heat up houses or pools. During the summer, the pipes do the opposite and absorb heat from the houses to cool them off. This extra heat is then absorbed by the ground.