Disused mine shafts in South Africa could become high-tech green energy generation facilities. The country has been identified by UK-based energy start-up Gravitricity as an ideal destination to test new technology that uses gravity and weights.

According to Business Green, the innovative system harnesses the power of gravity by using a massive 2 000 ton weight suspended in a mine shaft to capture power generated by intermittent renewables (such as wind and solar) that can be released in seconds. When there is excess electricity, the weight is winched to the top of the mine shaft, ready to generate power. The weight is then released, turning the winches into generators that are able to rapidly produce a large burst of electricity or release it more slowly, depending on what is required.

‘As we rely more and more on renewable energy, there is an increasing need to find ways to store that energy – so we can produce quick bursts of power exactly when it is needed,’ says Charlie Blair, Gravitricity MD. ‘So far there is a lot of focus on batteries, but our idea is quite different.’

Gravitricity received a GBP650 000 grant from Innovate UK (the British government’s innovation agency) that will be used toward building a scale demonstrator later this year, and finding a site to install a full-scale prototype by 2020.

6 March 2018
Image: SA Tourism