WEDNESDAY 01 MAY, 2013 |
Seabed Energy Storage For Wind Farms
A novel concept from MIT engineers could deliver abundant wind power to national
grids by enabling offshore floating wind turbines to store energy using giant
cement spheres on the sea floor.
The MIT team say that with proper storage capacity, offshore wind power is now
capable of delivering upwards of 20 percent of U.S. electricity demand, and
believe their plan for underwater 'wind power, without wind' is feasible.
The concept works on the principle of hydrostatic pressure. Each sphere would be
around 30-metres in diameter and hollow to allow water to flow in and out. With
walls three-metres thick, the sphere would be so heavy it would also double as
an anchor for the turbine floating above. Whenever the wind turbine produced
more energy than needed, the excess power would pump seawater out of the sphere,
before letting it flow back in through a turbine to generate electricity.
A single 25-metre sphere, anchoring a wind turbine at a depth of 400 metres
could store up to six megawatt-hours of power. Multiplied a thousand times, the
MIT team says, and you have the equivalent energy output of a coal or nuclear
power plant for several hours, all the on-demand electricity needed to shore up
intermittency issues related to wind power.
Depending on the depth of the each sphere and its size, the researchers believe
the system could provide base-load utility-scale renewable energy from floating
wind farm platforms, weather permitting. They have calculated the cost of
building and placing a single sphere on the sea bed at about $12 million, but
say as manufacturing practices improve, costs would eventually reach six cents
per kilowatt hour Ė a price on par with fossil fuels.
So far the design hasnít gone beyond a 75-centimetre working prototype, with
plans to scale up to a 10-metre working model, but MIT has filed a patent on the
concept should funding become available in the future.
Other news for Wednesday 01 May, 2013
Return to main renewable energy news section
Other Energy Matters News Services