A gravity-fed energy storage system under development by Gravitricity may be more cost effective in the long term than batteries, according to a report by Imperial College London (ICL).
The Gravitricity technology could be particularly well suited to provide grid balancing and rapid frequency response services to grid operators, the report said.
It added that the technology has a low specific power cost and high cyclability, with a predicted levelised cost of energy storage of $141 a kilowatt a year.
The technology has high operational expenditure, but this is offset by a long project lifespan of up to 50 years, high power availability and zero percent degradation, ICL said.
Gravitricity technology will use a weight of up to 2000 tonnes suspended in mine shafts by cables attached to winches.
The weight is winched to the top of the shaft to capture renewable power and then dropped to release it when needed, with the winches acting as generators.
Gravitricity managing director Charlie Blair (pictured) said: “This independent report clearly shows that Gravitricity can be a very strong competitor in the frequency response market, where its low specific power cost and high cyclability sets it apart from other technologies.”
The company, which teamed up with Dutch lifting specialist Huisman earlier this year, plans to develop a 250kW demonstration project and test it early next year at a disused mine in Scotland.
The partners ultimately aim to scale up to 20MW commercial systems.
Image: Gravitricity
Boffins weigh up storage costs
By EBS