A company aiming to use old mine shafts as batteries to store renewable energy is to build a demonstration project showcasing its technology in Scotland. Gravitricity believes that it can use large weights on cables attached to winches on the surface to help to compensate for the intermittent nature of wind farms. The company estimates that the cost of its technology would be lower than the large-scale lithium ion battery deployment being considered by many renewable energy producers. The Gravitricity method means that on days when more electricity is being generated than is needed by the grid the weight would be lifted to the top of the mine shaft. Then when demand is outstripping supply the weight can be lowered, with the movement of the winches producing power. The Edinburgh company secured more than £600,000 of funding from Innovate UK, a public agency, two years ago and has raised £750,000 through a crowdfunding drive. Today it has announced plans to build a £1 million demonstration of its system in Leith. It has signed a land rental agreement with Forth Ports and work is scheduled to begin in October, which could mean that the equipment is operating by the end of the year. Instead of using a mine shaft a 16m-high tower will be used, with two 25-tonne weights capable of being hoisted to the top. The system will be hooked into the grid and is forecast to be capable of producing 250 kilowatts.
Times 11th May 2020 read more »