Energy from offshore wind could be stored below the seabed
22nd January 2019 | Commercial Energy
Scientists at the universities of Strathclyde and Edinburgh believe rocks in the seabed off the UK coast could provide long-term storage locations for renewable energy production. In a paper in Nature Energy, Dr Julien Mouli-Castillo of the school of geosciences at Edinburgh University described a technique that could be used to trap compressed air in porous rock formations found in the North Sea using electricity from renewables. The pressurised air could later be released to drive a turbine to generate large amounts of electricity.
Using the technique on a large scale could store enough compressed air to meet the UK’s electricity needs during winder, when demand is highest, the scientist’s study found and could help deliver steady and reliable supplies of energy from renewable sources – such as offshore and onshore wind and tidal turbines – and help efforts to limit global temperature rise as a result of climate change.
Offshore wind
The engineers and geoscientists at the universities used mathematical models to assess the potential of the process, called compressed air energy storage (CAES). The team then predicted the UK’s storage capacity by combining these estimates with a database of geological formations in the North Sea. Porous rocks beneath UK waters could store about 1.5 times the UK’s typical electricity demand for January and February, they found.
Compressed air energy storage would work by using electricity from renewables to power a motor that generates compressed air. This air would be stored at high pressure in the pores found in sandstone, using a deep well drilled into the rock. During times of energy shortage, the pressurised air would be released from the well, powering a turbine to generate electricity that is fed into the grid. A similar process storing air in deep salt caverns has been used at sites in Germany and the US.
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