Original URL: http://www.theregister.co.uk/2013/04/14/velkess_flywheel/

Flexible flywheel offers cheap energy storage

Low loss and low cost

By Richard Chirgwin

Posted in Science, 14th April 2013 23:58 GMT

Mechanical engineering isn't within the scope of Vulture South, so we'll welcome readers' input about whether this is genius or snake-oil: a Kickstarter project called the Velkess Flywheel hopes to offer low-cost energy storage.

Flywheels are good at storing energy, but building them to fine mechanical specifications can get expensive. The Velkess proposal is to use a flexible flywheel that deforms in response to mechanical stresses, rather than trying to overcome the engineering challenges of making rigid flywheels reliably and cheaply enough to act as off-grid energy stores.

The Velkess Flywheel's proposal is to use the cheap and common “E-glass” fibreglass as the rotating mass – something which the project's Bill Gray says has already been demonstrated at small scale, here.

Gray says the current prototype can store 0.5 kWh of energy. To act as a serious storage unit for off-grid power applications – replacing lead acid batteries for remote solar or wind installations – Gray wants to get the storage up to 15 kWh.

To do that, he says, the project needs to create a 750-pound (340 kg) flywheel to replace the current 25-pound (11kg) unit, and create a magnetic motor and bearing assembly that can handle the heavy flywheel.

The project's current Kickstarter is to design a brushless DC motor or generator that can run in a vacuum (reducing the friction losses to around 2 per cent per day, Gray hopes). ®

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