In this article you will find a list over the most important pros and cons of geothermal energy.
This list is based on the two main ways we harness geothermal energy today: Electricity generation with geothermal power plants and geothermal heating and cooling systems.
Advantages of Geothermal Energy
1. Environmentally Friendly
Geothermal energy is considered environmentally friendly. There are certain complications with harnessing geothermal energy (read about them in the disadvantages section), but these bear no weight compared to more conventional sources of energy such as coal and fossil fuels.
The carbon footprint of a geothermal power plant is minimal. Further developing geothermal resources are therefore considered to contribute to fight the climate crisis and global warming.
An average geothermal power plant releases the equivalent of 122 kg CO2 for every MWh of electricity it generates – One eight of a typical coal power plant.
Geothermal Power Plant in Cooper Basin, Australia.
2. Renewable
Geothermal reservoirs come from natural resources that are naturally replenished. Geothermal energy is therefore a renewable energy source.
3. Sustainable
Renewable sources of energy are also sustainable. In other words, geothermal energy is an energy resource that can sustain its consumption rate. Unlike more conventional resources such as coal and fossil fuels, the energy we harness from below the Earth’s surface will not run out any time soon.
4. Massive Potential
This is closely tide together with the fact that geothermal energy has a practically unlimited potential. Our energy consumption is not anywhere near the massive potential that is stored in the Earth.
Scientists believe our geothermal resources will outlast the Sun. In other words, we should be able to extract geothermal energy for several billion years into the future.
5. Stable
Geothermal energy is a reliable source of energy. There are little to no fluctuations in the flow of energy. Geothermal power plants have a high capacity factor, unlike wind and solar, which are unreliable in comparison.
This means that the actual power output is very close to total installed capacity. Geothermal is an excellent candidate for supplying the base load energy.
The global average power output was 73% of total installed capacity in 2005, but as much as 96% has been demonstrated.
Snow monkeys living life in a geothermal hot spring.
Disadvantages of Geothermal Energy
1. Environmental Issues
There is an abundance of greenhouse gases below the surface of the Earth, which may mitigate towards the surface and be released into the atmosphere. There can also be traces of heavy metals such as mercury, arsenic and boron. The environmental issues with geothermal energy are far less critical than those of fossil fuels and coal.
2. Surface Stability
Construction of geothermal power plants can affect the stability of the land. In fact, both in Germany and New Zealand, geothermal power plants have lead to subsidence (motion of the Earth’s surface).
Earthquakes can be triggered due to hydraulic fracturing, which is an important aspect of constructing enhanced geothermal system (EGS) power plants.
Just a couple of years ago (January 1997), the construction of a geothermal power plant in Switzerland triggered an earthquake with a magnitude of 3.4 on the Richter scale.
2. Expensive
A commercial geothermal power project is expensive. Exploration and drilling for new resources carries a steep price tag. The costs usually end up somewhere around $2-7 million for a capacity of 1 MW. This is included drilling, which is accountable for over half of the expenses.
Not all resources can be extracted in a cost-effective manner, at least not with the current technology, subsidies and energy prices.
Initial cost of residential geothermal heating and cooling systems are also expensive. These systems can save you money years down the line, and should be looked upon as long-term investments.
The bottom line is this: Geothermal energy is environmentally friendly, cost effective, sustainable and a reliable source of energy. How much of an influence geothermal energy will have on our energy system in the future is dependent on technological advancements, energy prices and political interests (subsidies).
Start with How Can We Use Geothermal Energy? if you want to learn more about geothermal energy.
You might want compare this article to the rest of the pros and cons series:
Solar Energy Pros and Cons
Hydroelectric Energy Pros and Cons
Tidal Energy Pros and Cons
About the Author
Vic
November 24, 2011 at 1:05 amGeothermal is always promoted as being very clean and green. This is not entirely true. While it is certainly clean, it is merely a heat transfer process. It brings heat from the inside the earth to the surface of the earth where is it converted to electricity. It does not contribute in any way to increasing greenhouse gasses but it does increase the warming of the surface of the planet. The heat being used would have remained under the earth’s surface but geothermal processes would bring this heat to the surface where it would remain and contribute to global warming. Of course this is inconsequential if it is implemented in small ways. But it should probably keep us from ever developing it on a large scale.
Mathias
November 28, 2011 at 10:10 pmThanks for the comment, Vic.
However, I don’t think this heat contribution is significant to global warming. Here’s why:
-If we are talking about geothermal electricity generation, most of the heat is used to generate electricity (the rest being loss due to inefficiency).
-We may be worse off by not using geothermal energy, e.g. heating houses with electricity compared to waste water from geothermal power plants.
It is true that by harnessing geothermal energy, there is a net increase in surface temperature, as well as a net decrease in temperature under the surface. I’m curious whether there are any sources stating that this contributes in any significant way to global warming?
Best regards,
EnergyInformative.org
Aaron
December 16, 2011 at 5:37 pmVic,
Please understand what you are talking about before rendering opinions. First off there are two types of “geothermal” systems, true geothermal and heat pumps. True geothermal uses the earth’s inner heat that has been generated by radiation from the core. Think volcanoes and Old Faithful. True, this can and does bring more heat to the surface, but it statistically is inconsequential when referencing global warming. The direct and local affect on purge water in large power plants using geothermal can be a problem though.
The second type uses latent energy that has been stored in the soil directly from the sun. Using this heat will NOT affect global warming at all because it naturally conduct and transfer to the atmosphere anyhow. Now, greenhouse gasses… where do you think the electricity comes from to generate the energy to run the heat pump? Fossil fuels mostly, aka greenhouse gases. True it doesn’t burn anything locally, but that doesn’t mean that geo’s have a net zero carbon footprint. You are purchasing electricity that has been made from the burning of natural gas and coal.
Paul
March 9, 2012 at 8:23 pmThank you for the interesting comment.
However, I don’t think this heat contribution is significant to global warming because global warming isn’t real. There is no science backed up to that theory and there never will be.
Matt
April 30, 2012 at 3:50 pm…Are you mentally challenged?…
Sam
January 10, 2012 at 4:49 pmwow .
Jordan
January 11, 2012 at 4:47 pmI know right Sam.
Sam
January 12, 2012 at 4:56 pmAaron , why are you yelling at Vic when he is completely right ? I’ve done research and he is smart !
(A Different) Aaron
January 15, 2012 at 10:53 pmI really hope that’s sarcasm, Sam.
Val
January 13, 2012 at 8:33 amThank you, well done, well synthesized, perfect for my homework.
James
January 17, 2012 at 3:29 amGreat article. Quick question. Can solar (PV) (and a backup battery array) be used to power the heat pump and any other powered devices that work in conjunction with a Geothermal system? Thanks, -J
Mathias
January 17, 2012 at 6:42 amYou can use the electricity that is generated by photovoltaics to power anything you want. In fact, you can become completely energy self-sufficient if you use some of these technologies together.
You can read more about this in Energy Self-Sufficient With Wind and Solar Energy (which of course also can be done with other energy sources than wind and solar).
You’ll have to ask the producers whether a specific heat pump would fit together your battery backup array.
Sam
January 17, 2012 at 4:47 pmNo , Aaron . I’m serious . : )
Sam
January 17, 2012 at 4:51 pmAnd you’re welcome Vic !
Ken
January 27, 2012 at 7:34 pmYour comments in cons for geothermal say that the intitial cost is steep and will be a long term payback while your solar cons say initial cost is somewhat or fairly steep and will take a few years to pay back.
Geothermal heat pumps are much more economical (quicker payback) than solar due to its reliability for base load and working 24/7/365. Your comments seem to have a solar bias as many people do. The geothermal uses stored solar energy from the ground to heat your home. It is just a solution for the solar/thermal storage challenge. Don’t down play a more reliable solution just because it is not as visable as solar or wind.
Mathias
February 20, 2012 at 7:44 amYou are absolutely right and I edited the cons list to include this.
Thank you for contributing!
Valdemar
February 21, 2012 at 3:58 pmI agree with all the 14 people
Glenn
February 28, 2012 at 12:56 amI am working on making a small powerpoint presentation on geothermal energy. This will certainly help me a bit. Thanks!
andy
March 20, 2012 at 3:44 pmwow geothermal energy is cool this info will really help with my project
Bonnie
March 21, 2012 at 5:41 pmI have to debate the topic and unfortunatly, I have to take the con side. This has helped a bit, but I heard something about companies trying to dig where the heat source is too deep causing the ground to heave making buildings fall and destroying towns. Is that true?
Stan
March 23, 2012 at 7:11 amThe article says the following about the issue:
“A couple of years ago (January 1997), a geothermal power plant in Switzerland triggered an earthquake with magnitude of 3.4 on the Richter scale.”
barb
April 27, 2012 at 9:49 pmCan you tell me if their are any ill health effets living close (2 to 3 miles) to a geothermal plant? Thank you, anyadvice would be greatly appreciated.Sincerely, B.C.
Mathias
April 27, 2012 at 11:16 pmI think it depends on the situation. Svartsengi Geothermal Power Station in Iceland is located right next to a big bathing Resort (Blue Lagoon) without any adverse effects.
Geothermal power plants do release carbon dioxide (CO2) and hydrogen sulfide (H2S), which both can be dangerous for people. Arsenic, mercury, lithium and boron can contaminate drinking water.
There are safety features around geothermal power plants that should minimize these issues. Contacting the company behind the geothermal power plant directly would be the best thing to do to learn more about this.
Barbara Ceder
April 28, 2012 at 1:55 amHow do I ask you a question?