German Institute Successfully Tests Underwater Energy Storage Sphere
March 7th, 2017Viable anytime soon? No.
Cool idea anyway? Yep.
Via: Ars Technica:
A German research institute has spent years trying to tailor pumped storage to ocean environments. Recently, the institute completed a successful four-week pilot test using a hollow concrete sphere that it placed on the bottom of Lake Constance, a body of water at the foot of the Alps. The sphere has a diameter of three meters and contains a pump and a turbine. Much like traditional pumped storage, when electricity is cheap, water can be pumped out of the sphere, and when it’s scarce, water can be let into the sphere to move the turbine and generate electricity.
The Fraunhofer Institute for Wind Energy and Energy Systems Engineering envisions spheres with inner diameters of 30m, placed 700m (or about 2,300 ft) underwater. Assuming the spheres would be fitted with existing 5 MW turbines that could function at that depth, the researchers estimate that each sphere would offer 20 MWh of storage with four hours discharge time.
In an underwater “energy park,” dozens of these spheres could be connected near an offshore wind farm to create a system that would be able to add extra reliability to a renewable-heavy grid. The institute admits that the economics of this project only work on a large scale. It estimates that more than 80 spheres would be needed “to achieve a relevant overall performance/capacity for the energy market.”
