Cheaper solution found
Old mine shafts may be answer to energy storage
Charlie Blair at Newtongrange Mining Museum, Scotland
A new form of energy storage, using massive weights in disused mine shafts, could prove a cheaper alternative to batteries, an industry reports says.
Edinburgh start-up Gravitricity has patented its multi-weight system, which uses up to 24 weights totalling 12,000 tonnes stacked in a mine shaft, to capture power and then release it in miliseconds.
The company has received a £640,000 grant from Innovate UK, the UK Government’s innovation agency, and has teamed up with Dutch winch specialist Huisman to build a 250kW scale prototype.
A report by independent analysts at Imperial College London, working independently via Imperial Consultants, predicts that Gravitricity’s multi-weight system offers a better long-term cost of energy storage than batteries or other alternatives.
This leaves the firm ideally placed to tap into the growing energy storage market, which Bloomberg New Energy Finance estimates will be worth $620 billion globally up to 2040.
“The climate emergency means we need to find new ways to capture and store green energy so we can use it when we need it,” says Gravitricity managing director Charlie Blair.
“Our idea is very simple. We use excess energy to lift a massive weight or weights to the top of a shaft. These can then be stacked and released when required, delivering energy rapidly back to the grid.
“The beauty of this is that this can be done multiple times a day for many years, without any loss of performance. This makes it very competitive against other forms of energy storage – including lithium ion batteries.”
Gravitricity has already received support from a number of angel investors and is now about to launch a crowdfunding campaign with CrowdCube to support its plans.
Initially the firm will target former mine shafts, then in the longer-term it plans to sink purpose-built shafts wherever required. The firm is in discussion with mine owners in the UK, South Africa, Finland, Poland and the Czech Republic.