Geothermal energy storage is a form of energy storage using natural underground heat to generate and store energy. It is considered one of the renewable energy alternatives that can act as a substitute for fossil fuels in the present and future.
How Does Geothermal Energy Work?
Normally, geothermal energy is stored in hot water underground. It is difficult to take advantage of this energy source unless hot water makes it through the Earth’s crust in the form of hot springs or steam. However, with geothermal technology, we can finally make use of this energy. According to the U.S. Department of Energy, there are three main types of geothermal energy plants.
3 Types of Geothermal Energy Plants
The most common type used today is a dry steam geothermal power plant. The plant directs underground steam to flow through a turbine. As the steam goes through, it drives a generator that produces electricity.
The second type is a flash steam power plant. This is a little more complicated. Instead of using steam, a pump pushes hot fluid up to a tank on the surface. Then, the fluid cools and quickly turns into vapor. Similar to steam, this vapor will drive a generator that produces power.
The last type is a binary cycle geothermal plant. This plant also uses underground hot fluid. It pumps the hot fluid to the surface, then use it to heat a cooler fluid. This process is called heat transfer. When the cooler fluid is heated up to its boiling point, it will transfer to vapor. The vapor then spins a turbine that drives a generator to produce energy.
How Does Geothermal Energy Storage Work?
Technology can transfer heat energy from underground water to electricity, then it can also store the extra energy into underground water. Unlike other widely used energy storage such as battery, thermal energy storage, and solar storage, geothermal energy storage stores energy in subsurface groundwater.
According to the Environmental Department of Canon Global, a geothermal energy storage system consists of two separate groundwater wells–one for cold water and the other for warm water. Both of them are connected to an aquifer. It operates differently in the summer and winter. When the weather is hot in the summer, cold groundwater from the cold aquifer is used to cool the building.
As heat transfers from the building to the water, the warmed-up water will be taken to the well that stores warm water. In the winter, the warm water is used to warm up the building, and as the warm water transfers the heat to the building, it cools down and is taken to the cold water well.
How Does Geothermal Energy Storage Benefit Us?
- Less emissions of CO2
- Recycle wastewater
- Preserve the minerals in the soil
- Lower utility costs for your facility
According to the U.S. Department of Energy, the U.S. Geological Survey estimates once geothermal energy storage is developed successfully, it can support “10% of today’s energy needs.”
Geothermal energy also has been catching the attention of the U.S. government. According to Think Geoenergy, “There is enormous untapped potential for geothermal energy in the United States,” said U.S. Secretary of Energy, Rick Perry. “Making geothermal more affordable can increase our energy options for a more diverse electricity generation mix and for innovative heating and cooling solutions for all Americans.”