Gravitricity energy

Scottish energy storage specialists Gravitricity is looking for decommissioned or underused mine shafts to store electricity and has teamed up with South African energy consultancy RESA to identify suitable mine shafts for their gravity-based energy storage technology.

Gravitricity has developed an innovative energy battery which works by raising multiple heavy weights – totalling up to 12 000 t – in a deep shaft and then releasing them when energy is required.

This article first appeared in Mining Review Africa Issue 4, 2020
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Analysts calculate their system – which can operate for up to 50 years – can store energy at half the cost of lithium-ion batteries – and already the ‘greentech’ pioneers are planning to install their invention in decommissioned mineshafts across Europe.

They are now looking to South Africa as a next step.

“Our technology is ideal for South Africa, and we want to speak to mine owners and operators to identify sites for our first Africa project,” explains Gravitricity MD Charlie Blair.

“The country has an ambitious target to develop more renewable energy, but at the same time there is a lack of supply and robust grid infrastructure to carry power to factories and people’s homes – particularly at peak times. This is leading to local curtailment, load shedding and blackouts.

“Our technology utilises unused mine shafts to store excess energy and then release it when required – either in very rapid, short bursts or over a long period of time. This can deliver vital services needed to balance the grid at a national level or provide renewably powered mini grids associated with mine operations.

“We are particularly interested in South Africa given the number of mine shafts and their depth – which means we can store greater quantities of power – and would like to hear from mine owners keen to collaborate,” Blair continues.

The firm has teamed up with South African energy consultancy RESA and specialist consultants Caelulum. Together they will scope out suitable sites starting with their field trip this month – the first in a number of visits. In the following months they will assess the commercial potential of a range of sites, select suppliers and make a final site selection.

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“The South African electricity market is in crisis. Since 2008 the country has been faced with intermittent periods of load shedding. Even though the renewable energy technologies brought online by the country’s Renewable Energy Independent Power Producers Procurement Programme (REIPPP) provide a cleaner, greener solution to our country’s electricity supply problems, it does not solve the problem of intermittent electricity supply to the South African grid,” says Dr Melani De Lima from RESA.

Within this project Gravitricity’s role is to guide the technical and commercial aspects and identify relevant sites for deployment of its energy storage technology.

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