Jan 22 2019
According to a new study, rocks in the seabed off the UK coast could serve as long-term storage locations for renewable energy production.
Using a sophisticated method, compressed air could be trapped in porous rock formations present in the North Sea by making use of electricity from renewable technologies. The pressurized air could then be released to run a turbine to produce large amounts of electricity.
Fulfilling Demand
The research found that when the method is used on a large scale, adequate compressed air could be stored to satisfy the UK’s electricity requirements during winter when demand is the highest.
The technique could help offer reliable and steady supplies of energy from renewable sources, for example, wind and tidal turbines, as well as assist efforts to reduce global temperature increase due to climate change.
New Processes
However, based on climatic conditions, the amount of energy generated by several renewable technologies varies. Researchers suggest that new processes are required that can store energy reliably and at a low cost for months together.
Energy Potential
Mathematical models were used by geoscientists and engineers from the Universities of Edinburgh and Strathclyde to evaluate the capability of the process, known as compressed air energy storage (CAES).
The researchers then combined these estimates with a database of geological formations in the North Sea and estimated the storage capacity of the United Kingdom. They found that the porous rocks underneath UK waters could store about one and a half times the UK’s typical electricity requirement for January and February.
Air Storage
Compressed air energy storage would function by powering a motor that produces compressed air using electricity from renewables. Subsequently, this air would be stored at high pressure in the pores present in sandstone, with the help of a deep well drilled into the rock.
At times of energy shortage, the pressurized air would be released from the well to power a turbine to produce electricity that is supplied to the grid. At sites in the US and Germany, a similar process of storing air in deep salt caverns has been employed.
According to the researchers, by positioning wells nearer to renewable energy sources—for example, offshore wind turbines—the process would be made more economical and more efficient, and the required number of undersea cables would be limited.
The research has been reported in the journal Nature Energy. It was funded by the Engineering and Physical Science Research Council, the Scottish Funding Council, and the Energy Technology Partnership.
This method could make it possible to store renewable energy produced in the summer for those chilly winter nights. It can provide a viable, though expensive, option to ensure the UK’s renewable electricity supply is resilient between seasons. More research could help to refine the process and bring costs down.
Dr Julien Mouli-Castillo, School of GeoSciences, University of Edinburgh