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| Fig. 1: Iceland's Geothermal Plant known as the Krafla Power Station. (Source: Wikimedia Commons) |
Since the Paleolithic era humans have been capturing the thermal energy stored within the Earth and using it for heating purposes. With the outbreak of new technology it became possible to utilize the hot water and steam beneath the Earth's surface to not only heat a given space, but also to convert that energy into electricity. Geothermal energy, which literally translates to "Earth heat," can be used in three different ways: direct geothermal energy, geothermal heat pumps, or geothermal power plants. Direct geothermal energy is possible in areas where there are hot springs or reservoirs close to the surface of the Earth. Hot water is transported to different locations via a network of pipes, and can subsequently be recycled and reheated. The other two methods require a similar network of pipes, but more complex technologies for tapping into the Earth's inner layers and warm temperatures. The United States is currently the world's leader in geothermal energy, followed by the Philippines, Indonesia, and Mexico. [1] Scandinavian countries, particularly Iceland, are located on ideal geographical grounds for geothermal energy, and will thus be the focus for the rest of the essay.
Arguably one of the most successful countries at efficiently harnessing geothermal energy is Iceland. Although it is the world's sixth leading country with regard to geothermal power, its geographic features make it a prime candidate for using the Earth's heat for energy. These features include Iceland's large underground reservoirs of water that are continually renewed by levels of annual precipitation, and its low plumes of magma that heat the reservoirs. [2] In 2008, Iceland's National Energy Authority stated that 99 percent of Iceland's electricity came from renewable sources, 30 percent of that total from geothermal energy and the rest from dams. [2] Reykjavik, the capital of Iceland, has the largest district heating system across the globe, and 90 percent of all households in Iceland are connected to a district heating system. [2] Today, Iceland stands as the world's leading consultant on geothermal technologies and is currently advising Germany and China on how to incorporate geothermal power in their respective nations. [2] Moreover, there is a proposal to construct a 600-mile power line between Iceland and the United Kingdom to export Iceland's abundant geothermal power. [3] The idea for Iceland to export energy has rapidly grown more politically palatable within the EU given the EU's commitment to decreasing its carbon emissions. Equally as important, government officials within Iceland believe this could be an opportunity for Iceland to tap into a lucrative market. Iceland's largest geothermal plant, Krafla, sells only 17 percent of its geothermal electricity to households and local industries, and the rest goes primarily to foreign aluminum smelters. [4]
Geothermal energy like other renewable energy sources has its downsides. Perhaps its greatest disadvantage lays in the fact that it requires a very precise geographic climate. Countries located within the Ring of Fire along the Pacific Ocean are optimal geothermal candidates, because volcanoes are readily present throughout this region and high temperatures are found close to the surface. [1] Nevertheless, compared to other modes of renewable sources, the installation and production fees for geothermal energy are more economical per kilowatt-hour. [5] It is also important to note that unlike wind or solar power, geothermal energy can be generated consistently throughout the 24-hour day. If countries like Iceland are able to successful export their supply of renewable energy to other regions throughout the world, then geothermal energy might prove to be a giant step toward mitigating global climate change.
© Alejandro Rosenkranz. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] K. Galbraith, "Geothermal Industry Grows, With Help from Oil and Gas Drilling," New York Times, 13 Jul 14.
[2] C. Mims, "One Hot Island: Iceland's Renewable Geothermal Power," Scientific American, 20 Oct 08.
[3] J. Plester, "Wind from Britain, Solar from Sahara, Geothermal from Iceland," The Guardian, 22 Nov 15.
[4] A. Higgins, "Iceland Looks to Export Power Bubbling From Below," New York Times, 20 Feb 13.
[5] B. Crowe, "Geothermal Energy," Physics 240, Stanford University, 22 Nov 12.
