Some areas across the globe are producing too much electricity due to an abundance of wind. When energy demand at night is low, high winds are not an advantage, as too much electricity is being produced for the grid. However, recently, scientists have come up with a solution to this problem.
New studies from the USA show that energy generated by wind turbines could be stored deep underground in porous rocks to be used at a time when energy demand is higher and power supplies are put under a greater strain. The Department of Energy’s Pacific Northwest National Laboratory and Bonneville Power Administration in the have teamed up to put this theory into practice.
The new plants can switch from energy generation to energy storage in a matter of minutes, allowing flexibility for the variations in wind generation throughout the day and night. This concept could help manage and integrate more renewable energy into electricity grids across the world, encouraging further clean energy production.
So how does it work? When there is abundant energy, it is drawn from the grid and used to power a large air compressor which pushes pressurised air into an underground storage area. When the electricity is required again, the stored air is released back to the surface where it is heated and rushes through turbines to generate electricity.
It is thought that these plants can re-generate up to 80% of the electricity they take in. There are currently two such plants existing, one in Alabama and one in Germany, both using man-made salt caverns to store excess energy, however research is being done into using existing rock formations.
With more turbines being installed everyday, this concept could help us use even more renewable energy in the future.