Advantages and Disadvantages of Enhanced Geothermal Power Plants
Using enhanced geothermal energy systems could be the answer to achieving net zero emissions. The technology provides a very low carbon energy and if used the amount of electricity to be produced is abundant. However, for all its advantages, experts warn that using such systems might increase the chance and risk of earthquakes.
An example of such an enhanced geothermal energy plant are the Geysers which are situated in the Mayacamas Mountains in California. The Geysers are the largest geothermal plant in the world, they produce enough electricity to power three quarter of a million households and produce no greenhouse gases. This impressive geothermal plant generates 20 per cent of all renewable energy in California.
The Geysers show why some people argue that geothermal plants are the straightforward answer to climate change. They produce cheap, predictable, reliable and renewable energy.
However, very few locations around the world have such ideal conditions to setup a geothermal power plant. The Geysers were built over steam and reservoir which both occurred through nature. Therefore, this has led to some experts in the field believing that these conditions can be recreated in other locations to provide similar results by pumping water into the ground to make use of the natural heat sources. This idea however has come under criticism by other experts which believe that the techniques that would be used to create these conditions may increase the risk of earthquakes.
Inevitably faults with eventually slip, however enhanced geothermal energy systems could speed up the time in which they will slip and therefore cause earthquakes to happen more often. The enhanced geothermal energy systems pumps water in a similar manner to how it is done for hydraulic fracking which is used to drill for oil and natural gas however it is just done at lower pressures.
The water then creates an underground reservoir which is heated, and then pumped back up to the surface to produce electricity. If this technology is used then it will make many more sites around the world able to generate electricity from geothermal power plants. Effectively, you would be able to create a plant anywhere as long as you drill deep enough you will find the heat required to heat the water.
The technology could also improve already very efficient sites. The Geysers for example would benefit from it as there are certain places which have natural hot rock but no reservoir to make use of it.
Originally, researchers believed that the geothermal plant technology would only cause small tremors through the ground however recent research shows differently. A recent earthquake in Pohang, South Korea is believed to be caused by the enhanced geothermal plant technology. The earthquake had a magnitude of 5.5 and led to £57.5 million worth of damage being done. Previously, it was thought an earthquake of this scale could not be caused by such technology.
However, other experts believe that there are a range of other factors which could have led to this earthquake and pushed back the idea that it was the enhanced geothermal power plant that caused it.
Experts have conflicting views on the matter and how much the risk of an earthquake will increase due to a geothermal plant. However, many agree that the closer the plant is to a fault, the higher the risk of an earthquake being caused. Therefore if the technology is to be used, the geothermal plants should be located in places far from faults to minimise the risks or an earthquake being caused.