Geothermal power in Iceland is the use of geothermal energy to generate electricity. Iceland's active geology creates natural conditions that are especially suitable for using geothermal energy. For many years, Icelanders have used geothermal energy directly, such as for heating homes and public baths. More recently, Iceland began using geothermal energy more widely as a power source to stabilize energy prices and increase energy independence. This allowed Iceland to rely more on geothermal energy for both heating and electricity, which helped reduce the country's carbon emissions.
The growth of geothermal power in Iceland is supported by the Icelandic government. As of 2020, Iceland had 799 megawatts (MW) of installed geothermal power capacity. Geothermal energy produces more than a quarter of Iceland's total electricity.
Geology
Iceland's land is among the most geologically active areas on Earth. The country is located across the Mid-Atlantic Ridge, which is a crack where Earth's plates move apart, and it sits above a volcanic hotspot. These conditions cause frequent volcanic activity and geothermal energy. Additionally, Iceland has underground water reservoirs that are filled with rainwater over time. Hot magma beneath the island heats these reservoirs to very high temperatures. There are at least 25 of these geothermal aquifers in the volcanic area. These natural conditions in Iceland are good for producing geothermal energy.
History
Geothermal energy has been used by Icelanders since the Viking Age for tasks like washing and bathing. Over time, it was used to heat homes, greenhouses, swimming pools, and to melt snow on streets and sidewalks. Today, at least 90% of homes in Iceland are heated using geothermal energy.
The Blue Lagoon is a well-known geothermal bath. It is made by mixing seawater with water from the nearby Svartsengi Power Station. The Blue Lagoon covers an area of 5,000 square meters and is one of Iceland’s most visited places.
Although geothermal energy has been used in Iceland for many years, it was not used to produce electricity until more recently. Before the 1970s, most of Iceland’s energy came from fossil fuels. In 1970, Iceland’s National Energy Authority, Orkustofnun, suggested increasing the use of geothermal power and hydroelectricity to lower energy costs and reduce dependence on outside energy sources. In 1973, an international energy crisis began, causing oil prices to rise and making energy supplies unstable. This crisis led Iceland’s government to focus more on using local energy sources like geothermal power. The growth of renewable energy in Iceland was mainly driven by the need for energy independence and the high costs of energy during the 1970s crisis. Since then, Iceland has become more energy independent, and its electric grid has become cleaner with less pollution.
Iceland’s government supports the use of renewable energy for power production. These policies were created to solve past energy problems, such as when oil prices increased in the 1970s. At that time, the government replaced oil with geothermal energy for heating homes, which greatly reduced heating costs.
As geothermal projects advanced, the National Energy Authority created a two-phase plan to expand geothermal energy use. The first phase, from 1999 to 2003, focused on collecting data. The second phase, from 2004 to 2009, included research in the first half and evaluating geothermal areas in the second half. The plan considered 24 possible geothermal projects. Many of these projects are still being reviewed by Iceland’s Parliament today.
The government still faces challenges in providing geothermal heating to all homes, as some villages and rural areas lack the necessary infrastructure. To solve this, the government continues to explore areas for geothermal energy projects. In 2019, a 20-km hot water pipeline was built from a geothermal field to the town of Höfn, replacing electricity as the heating source for 1,800 people.
Iceland’s government also works to help other countries use renewable energy like geothermal power. One example is the African Rift Geothermal Development Facility Project, started in 2010, which works with the United Nations Environment Programme (UNEP) in countries like Ethiopia, Kenya, and Rwanda. Iceland also helps train geothermal engineers worldwide through the United Nations University Geothermal Training Programme.
Consumption
Iceland is located in an area with a lot of geothermal activity. In 2020, 70.38% of the energy used in the country came from geothermal sources. This means that 173.2 petajoules (48,100 GWh) of the total 246.1 petajoules (68,400 GWh) of energy used in Iceland that year was from geothermal sources. Geothermal energy is used in two main ways: directly for heating and indirectly to produce electricity.
Most geothermal energy in Iceland is used for heating. In 2020, the largest use of geothermal heat was for space heating, which used 23,094 terajoules (6,415 GWh). Other uses included heated swimming pools (3,628 terajoules or 1,008 GWh), snow melting (2,036 terajoules or 566 GWh), fish farming (1,404 terajoules or 390 GWh), greenhouses (429 terajoules or 119 GWh), and industry (393 terajoules or 109 GWh). These direct uses rely only on geothermal heat and avoid energy losses that occur during electricity generation. Many of these applications use water to transfer heat. In Reykjavík, hot water from 100° to 300°C is used to heat homes. This water is then cooled to 30°C (86°F) and sent through plastic pipes under streets and sidewalks to melt snow and ice.
In 2020, Iceland was able to meet all of its electricity needs through geothermal and hydropower energy. Hydropower and geothermal sources produced 99.94% of Iceland’s electricity, with 13,157 GWh from hydropower and 5,961 GWh from geothermal energy. Geothermal energy provided more than a quarter of Iceland’s electricity.
However, in the summer of 2021, droughts caused water levels in hydropower reservoirs to drop. At the same time, electricity demand increased, leading to a shortage of electricity. To reduce demand, the Icelandic government limited electricity use in some industries. This shortage, caused by changes in hydropower supply, has made Iceland consider expanding its power generation infrastructure.
Electricity production infrastructure
According to the National Energy Authority of Iceland, in 2020, Iceland's geothermal power facilities had a total installed capacity of 799 megawatts (MW), accounting for 25.9% of Iceland's total power capacity, in addition to power from hydropower, wind, and fossil fuels.
According to Askja Energy Partners, an energy consulting firm in Iceland, the three companies that own and operate the largest geothermal power stations in Iceland are HS Orka, ON Power, and Landsvirkjun (National Power Company of Iceland).
Nine power plants contribute the most to Iceland's geothermal power production capacity. The ownership of each geothermal power plant is also noted.
In Reykjavík, hydrogen sulfide (H₂S) released from two nearby geothermal power plants, Hellisheiði and Nesjavellir, may have affected the health of nearby residents. A study by the University of Iceland in 2012 found that weather conditions that allow H₂S levels in Reykjavík to exceed the national 24-hour health limit of 50 micrograms per cubic meter (μg/m³) are expected to occur about twice each year on average.
Iceland is also investing in geothermal energy research projects, such as the Iceland Deep Drilling Project (IDDP). If successful, the technology being developed by IDDP could produce ten times more power than current geothermal technology. By drilling more than 15,000 feet (4.5 km) deep into volcanic fields in Iceland's Reykjanes Peninsula, researchers are studying the use of supercritical fluids to harness geothermal energy. If achieved, projects like IDDP could increase the amount of Iceland's electricity generated from geothermal sources.