Why Geothermal, Why Now?

Humans have been using geothermal energy since Paleolithic times, and harnessing this energy for electricity has existed since the 1900s. Still, even though the technology is old, it is only recently that we are turning again to geothermal. Currently, geothermal energy supplies 0.3% of global electricity demand with output growing 3% annually. An extra 28 GW of geothermal heating is used for space heating, spa heating, desalination and more.  [Source: Wikipedia].

One of the major benefits of geothermal is its reliability. Unlike solar and wind, geothermal energy does not rely on variable sources of energy as the energy comes from the formation of the earth, radioactive decay of minerals and solar energy absorbed from the surface. Geothermal has an average capacity factor (how often the power plant runs) of about 73% [Source: IEA Geothermal Energy] though some have been recorded as high as 98%. Compare that to 20-40% for wind farms, around 19% for solar [Source: Treehugger] and coal running at 65-75% [Source: REPP], and it becomes clear to see why more countries are investing in geothermal.

It’s not just the capacity factor that makes geothermal very attractive, but the fact that this energy source alone could potentially power the entire world. The heat from the core to surface flows via conduction at a rate of 44.2 terrawatts (TW) [Source: AGU], though not all of the energy is recoverable. Technological advances have allowed countries to utilize areas that might not have been possible. Generally, geothermal plants require sites to have a reservoir of water/steam and porous rocks. With the creation of the enhanced geothermal system (EGS), however, many of these issues have been resolved. The EGS pumps high pressure cold water through fissures in non-porous bedrock (generally granite). The injection increases the fluid pressure in these fractures which then creates a shearing event to increase fractures in the rocks. The cold water travels through the fissures and absorbs the heat from the rocks. Eventually they exit as hot water and produces electricity [Source: US Department of Energy]. An MIT report stated that with the EGS, currently 200 zettajoules (ZJ) were extractable, though with technological advances 2,000 ZJ could be possible, enough to power the world for several millenia. Unfortunately, the EGS has been reported in 2008 as causing earthquakes. Markus Haring was injecting high pressure water into rock fissures and caused some 30 earthquakes in Basel, Switzerland. While the EGS is bound to cause some seismic activity, the key is to find the proper balance between the amount and speed at which the fluid is pumped [Source: Popular Science].

Many countries have begun to recognize the power of geothermal and are incorporating it into their power grid. Iceland is the most famous example, but Indonesia has recently hosted the largest geothermal forum in the world (Australia will host the next one in 2015) and also set some ambitious plans on harnessing the power of volcanoes in the pacific “Ring of Fire”. Unfortunately, startup costs for these power plants are very expensive and can take much longer to build than coal plants. Luckily, countries like Iceland and Japan are investing heavily in overseas building. Japan has invested $100 million USD in Indonesia [Source: Think Geo Energy] and $320 million USD to Kenya [Source: Venture Beats].  Corporations like Mitsubishi and Reykjavik Energy are packaging geothermal products to underdeveloped countries. The package includes: “funding, digging, construction and provision of operational know-how” [Source: Google AFP].

Other countries are implementing geothermal powers locally. The US has seen a growth of 26% new geothermal projects around the country thanks to the $787 billion federal stimulus. California and Nevada make up for 2,927 megawatts online of geothermal [Source: New York Times]. No surpise since the largest factory is located in California. Japan is also investing locally and has built their first geothermal plant in nearly twenty years though it won’t be in operation until 2016. The new project will aim to generate up to 60,000 kW of power [Source: Telegraph]. While many countries are taking strides in incorporating geothermal, there are only five countries that generate more than 15% of their electricity from geothermal sources: Iceland, Kenya, Costa Rica, El Salvador and the Philippines [Source: IEA Geothermal Energy].  Many countries, even Japan, are hesistant to incorporate geothermal for fear of depleting the resource. While geothermal is practically inexhaustible there have been reports of local depletion, though it will recover after a century. The modern practice of reinjecting spent geothermal fluids back into the earth and monitoring extraction, can be sustainably long-term as evidenced at Lardello fields in Italy and Wairaiki Fields in New Zealand [Source: Wikipedia].

As technology advances, the process of creating geothermal energy will become safer and more efficient. While the initial cost may be higher, the rate for electricity itself will decrease as will the environmental damage. Geothermal energy has been in practice for over a century and while we have yet to reach its full potential, we’ve finally begun to see the pressing issue of obtaining renewable and reliable sources of energy.

Treehugger
Jasmine Greene

57 comments

Grace Adams
Grace Adams5 years ago

I agree with Amitav--we need to diversify and use many different sources of power. Fossil fuel power is not going to go away over night. We need an assortment of bio-fuels (preferably from either waste or algae), wind, solar, and geothermal to replace fossil fuel gradually over the next ten to twenty years as the fossil fuel plants reach the ends of their design life.

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Tim O'Hara
Tim O'Hara6 years ago

Makes logical sense to harness Geothermal. Here in Canada I participate in the planning stages of incorporating the feasibility in a community.

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Renee M.
Renee M6 years ago

pretty cool information.

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Jewels S.
Jewels S6 years ago

I agree with Amitav, we need balance.

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charmaine c.
Charmaine C6 years ago

Sounds complicated and interesting. My fear is that we'll do the same with geothermal as we did with everything else on our planet. Overused and abused. There are already too many people and most of them will procreate and keep procreating. Energy and food demands are growing at unsustainable rates and when people get desperate they cannot be relied upon to make safe and sensible choices. We have nearly depleted millions of years worth of fossil fuel deposits in a few hundred years, regardless of the damage we knew we were causing, and we'll probably end up doing the same with geothermal causing massive earthquakes and damage in the poorer zones of the world where people matter less..if you see what I mean by that? Same as the developed countries are doing today with fossil fuel extraction. Those that have the most money will call the shots and control the resources.

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Amber K.
AB K6 years ago

Thanks for your post.

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Helen Snyder
Helen Snyder6 years ago

I'm all for alternative sources of power .. and I wish I could get my daughter to incorporate the methods compatible with our living arrangments. I am tired of Ameren's (our electric company) greed. Sometimes I wish I were about 50 years younger !

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Amitav Dash
Amitav Dash6 years ago

The problem with any energy source (like so many things in life) is that it can't be the sole provider of what we need. There is a reason why so many different possible sources of energy exist and why we need to manage and balance what we use and take from each. Even seemingly "green" or natural energy sources can end up causing potential disasters if we completely and solely focus on using them and them alone.

Balance, that's what we all need to seek...

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Antoinette Reyes
Antoinette R6 years ago

Spiritually I feel this is a disaster that many nations will pursue and will envoke the power of our mother upon us. I feel we have already extracted almost all that we have been able to dig up beneath her crust and now this. We are growing all but the right direction. I say all this just on the part that mentions of 30 earthquakes from one project. That is nothing to try and play with. I hope we stop making a mockery of our planet and stop angering her by playing god and announcing ourselves as the ruler of this land

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Glenn Askew
Glenn A6 years ago

I have been a supporter of Geothermal myself for a long time..and as to making no money with it...what??..think about it..If you are an electricity supplying company..and you build a Geothermal Power Generator..would you not hook it up to a grid and sell it to customers much the same as now..only difference would be where the power was coming from..unless one puts thier own small private system in thier home..they still gotta buy power from somewhere..right?? So..that means a big Corporation could STILL create jobs and make a ton of profit from selling thier Geothermal,(Solar and wind too).."resource".

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