International winch specialists Huisman have begun fabrication of a £1 million energy storage demonstrator destined for trial in Edinburgh early next year.
Work has started at the firm’s specialist factory in the Czech Republic and is expected to be complete in December. The custom-built winches and control system will be shipped from Rotterdam to Leith. At the same time the 250 kW demonstrator’s lattice tower is being fabricated by Leicester engineering specialists Kelvin Power.
The 16-metre high rig will then be assembled at a grid-connected site at the port of Leith for testing to begin in spring 2021.
Gravitricity’s have recently raised over £1.5 million for their technology development through a crowdfunding campaign and have also received a £640 000 grant from Innovate UK, the UK government’s innovation agency.
Commenting on the project, Gravitricity lead engineer Miles Franklin said: “Our demonstrator will use two 25-tonne weights suspended by steel cables. In one test we’ll drop the weights together to generate full power [through a 14 second drop] and verify our speed of response. 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.”
“We’ll then run tests with the two single weights, dropping one after the other to verify smooth energy output over a longer period, alongside a programme of other tests to demonstrate and refine the full capabilities of the system. This two-month test programme will confirm our modelling and give us … data for our first full-scale 4 MW project which will commence in 2021.”
The energy storage system works by raising multiple heavy weights – totalling up to 12 000 tonnes – in a deep shaft and releasing them when energy is required.
Gravitricity plans to roll out their technology in disused mine shafts located around the world.