New ball game for sea power storage

It’s only a proposal. But it’s an idea that could make offshore wind a lot more dependable and cost-effective, says the Massachusetts Institute of Technology (MIT): storing surplus energy from wind turbines in a concrete sphere under water. The principle is straightforward.

During periods when there is more wind energy than immediate demand, the additional power would be used to pump seawater out of a hollow, submarine sphere. Later, when power is needed, water would be allowed to flow back into the sphere through a turbine attached to a generator and the resulting electricity sent back to shore. MIT has calculated that a 25m sphere in 400m-deep water could store up to 6MWh of power.

Multiply that figure up and 1,000 turbines with this form of pumped hydro energy storage could rival a nuclear power station, for a matter of hours at least. The big drawback is a minimum 200m depth of water required to make the scheme feasible, especially as off-shore wind, which currently only enjoys popularity in Europe, is currently sited in waters shallower than 30m.

But the ability to provide despatchable energy without the need for large-scale batteries on or offshore is clearly a huge plus for the idea.

1 Comment on "New ball game for sea power storage"

  1. For 400 meter depth, the sphere has to be far away from the shore and will be subjected to at about 600 pound of pressure of sea water head.

    In my design for wind and solar power in Egypt, or any where mountains are close to the sea, I considered placing storage tanks on top of adjacent mountains (like in Qattara and along the red sea) to store seawater using excess generated sun or wind power to fill these tanks and use this stored water to run ground turbines to generate power on demand.

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