Geothermal energy can provide a highly dependable and virtually infinite source of energy. The constant activity of the Earth’s tectonic plates generates heat; we can find a near-constant temperature of about ten degrees Celsius after descending just 100 metres beneath the surface. The mean temperature rises by three degrees Celsius for every 100 metres deeper we go. With the help of various technical processes, it is possible to generate power using this geothermal energy.
There are three different processes in wide use for power generation. Near-surface geothermal energy, drawn from up to 400 metres deep, includes shallow geothermal energy that is ideal for private users. Industrial users can choose from deeper solutions, including geothermal processes that tap the warm water located underground up to 4,500 metres deep, and petrothermal geothermal energy technology which exploits thermal energy at depths of about 5,000 metres for electricity production.
In a 2011 report, the Intergovernmental Panel on Climate Change (IPCC) noted that the upper five kilometres of the Earth’s crust in Europe contained enough energy to supply the continent with about 4,000 terawatt hours of electricity and 2,000 terawatt hours of heat each year, which is roughly equivalent to Europe’s annual energy usage. Geothermal energy is also base-load capable, meaning that it can consistently generate power to meet demand, regardless of weather conditions. Unlike some other energy sources, geothermal plants take up very little space and do not require follow-up costs for alternative energy storage systems or conventional reserve power plants.
Acceptance of geothermal energy
Iceland, perched on the edge of tectonic plates, is one of the champions of geothermal energy. By switching from costly imported coal and oil to geothermal energy, Reykjavik has changed from a polluted place to one of the world’s cleanest cities. Most of the energy for heating and hot water in Iceland’s homes is now supplied by geothermal power plants. These plants had a total installed capacity of 665 megawatts and produced 5,239 gigawatt hours of power in 2014. Iceland has also discovered a new industrial use for geothermal power by using a power-to-liquid technology to create synthetic methanol, branded as Vulcanol.
Geothermal power has not found wide acceptance outside of places like Iceland, possibly due to the expensive investments involved. In 2015, the total installed capacity of geothermal power stations worldwide was just under 13 gigawatts, far below the projected level of 18.5 gigawatts.
In Germany, the accepted view of the energy revolution has been as an electricity revolution, but in fact more than 70 per cent of energy consumed by German households is used for heating purposes. Geothermal energy can find greater acceptance if it is viewed in the context of a heating revolution instead, as it is reliable and constantly available. Geothermal plants with parallel heat and electricity production also have ideal flexibility, as electricity generation can be shut down when heating demand is high, then resumed once the heating period ends.
TÜV SÜD provides a comprehensive suite of consulting and support services for geothermal plant investors, equipment manufacturers and plant operators. Our services are designed to ensure maximum yield, optimum operational efficiency and reduced cost through maintenance downtime.
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