Imagine living on 130 active volcanoes. Well this is the reality for Icelanders. Situated on a tectonic plate boundary, Iceland is one of the most volcanically active places on earth.
The people of Iceland have been crafty enough to take advantage of their active volcanoes by becoming a world leader in geothermal energy. Geothermal energy is completely renewable. With five geothermal power plants producing more than 25% of the country’s total energy output, Iceland has been a trailblazer in this space and we’re impressed.
How does geothermal energy work?
Wells are drilled thousands of metres into the ground to gain access to either reservoirs of pressurised water or water that has seeped into the crust through the seafloor. This water is continuously heated due to its close proximity to magma in the inner earth. Steam from this boiling water is then used to power turbines that produce electricity.
The Icelandic way.
Existing geothermal projects around the world use steam at temperatures less than 300°C. However, in Iceland some wells have been drilled 4 km deep below the Icelandic crust to gain access to water that is far hotter than usual, and in 2009 a record for hottest steam was set: a scorching 450℃.
Why bother you say?
Water at these hot temperatures is described as supercritical (neither liquid nor gas) meaning it retains a large amount of energy and can generate up to ten times more power than conventional geothermal sources. This means they can produce a gigantic 303MW from one their stations! This is enough to power 2/3 of the capital city of Reykjavik.
But wait, that’s not all.
The waste products from the Hellisheiði power station provides hot water to Reykjavik. Once the steam is used to power the turbines, it is diverted to a heat exchanger where it heats up a fresh water supply. This then flows through a well insulated pipeline down the mountain into the city providing renewable warm water showers. Our favourite!
Can Australia do this?
Geothermal exploration is being conducted in all states and the Northern Territory. However, whilst significant resources have been identified, at this stage there is no commercial production of geothermal energy as it is not economically viable due to technical, financial and geographical challenges. In 2015, energy company Geodynamics closed their geothermal electricity plant in the Cooper Basin after the cost of implementing the technology and the cost of delivering the electricity from the site proved greater than the return.
What lessons can we learn?
Iceland has taken advantage of its abundant renewable energy resources. Australia’s renewable energy sources have the potential to power the country 500 times over! Now is the time for Australia to pick up its game and capitalise on our vast access to solar and wind resources to generate more affordable, reliable and secure power.
Image Credit: 'Geothermal' by Flickr user Rob Oo, licensed under CC CY-NC-ND 2.0