Battery storage demo
Mine shaft energy system to be showcased in Leith
An Edinburgh company which hopes to use old mine shafts to store and generate electricity will demonstrate the system on an industrial site in Leith.
Gravitricity is renting land from Forth Ports to build a £1 million rig which it plans to have operational by the end of the year. Work is scheduled to begin on site in Bath Road in October.
It battery system works by using electric winches to hoist 12,000-tonne weights – half the weight of the Statue of Liberty– to the top of the shaft when there is plenty of renewable energy available, then dropping them hundreds of metres down disused shafts to generate electricity when needed.
The demonstrator at the Port of Leith will allow the technology to be trialled on a much smaller scale 25-tonne weights, using an above-ground structure.
Demonstrator to be built in Leith
The project is supported by a £640,000 grant from UK Government funder Innovate UK.
The firm is planning to install the system in repurposed mine shafts across Europe, South Africa and Australia.
Once the technology is proven in old mines the company intends to sink purpose-built shafts in areas close to wherever there is demand.
Analysts calculate that once commercialised it will be cheaper than the current leading forms of energy storage – half the lifetime cost of lithium-ion batteries.
Miles Franklin: ‘zero to full power in less than a second’
The system is the brainchild of serial innovator Peter Fraenkel who invented the world’s first full-scale tidal energy turbine, which was bought by Siemens.
Its uniqueness is in its flexibility to power short and long demands for electricity and ability to for recharging.
Lead engineer Miles Franklin said: “We calculate we can go from zero to full power in less than a second – which can be extremely valuable in the frequency response and back-up power markets.
“This two-month test programme will confirm our modelling and give us valuable data for our first full-scale 4MW project which will commence in 2021.”