THEY were thriving hubs of industry that fell on harder times when the mines fell silent. 

But now a green energy scheme which could revitalise Scotland's mining towns is ready to make the leap from the designers table and into reality.

Edinburgh-based Gravitricity has been awarded more than half a million pounds to develop technology which harnesses the power of gravity to create electricity.

The plan would see massive 2,000 tonne weights suspended over disused mine shafts on an intricate pulley system, which could be dropped down at the touch of button to create energy.

The developers say this would act like a battery for green energy and provide a sudden jolt to the grid when other sources such as wind power fell in capacity.

The firm are now on the look-out for locations to build a prototype, and say that the industry could one day revitalise towns in Lanarkshire, Fife and Midlothian which used to rely on mining with fresh jobs and economic activity. 

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“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,” said Gravitricity managing director Charlie Blair

“So far there is a lot of focus on batteries, but our idea is quite different. Gravitricity uses a heavy weight – up to 2000 tonnes – suspended in a deep shaft by cables attached to winches. 

“When there is excess electricity, for example on a windy day, the weight is winched to the top of the shaft ready to generate power. 

“This weight can then be released when required in less than a second. And the winches become generators, producing either a large burst of electricity quickly, or releasing it more slowly depending on what is needed." 

“It’s a simple case of ‘What goes up, must come down,’” he added.

The project has been awarded a £650,000 grant from the Uk Government to develop the technology, which is yet to be proven in the field.

However, the idea of using gravity to store energy is not new. Britain already relies on a number of pumped storage hydro schemes, such as Ben Cruachan, where water is pumped uphill to be released when required.

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Mr Blair said: “The difference is we don’t need a mountain with a loch or lake at the top, and we can react much faster.”

The biggest single cost of the project is drilling the hole for the weight, and that is why the start-up is developing their technology utilising existing mine shafts, both in the UK and also in South Africa. 

The start-up plans to build models capable of generating 1 to 20MW, and estimates each ‘Gravitricity Energy Storage System’ will last up to 50 years. 

The company plans to build and test a part-scale demonstration prototype later this year, and they are currently short-listing a number of disused mine shafts for the first full-scale working model in 2020.