The Koeberg nuclear power station near Cape Town provides 5% of capacity and hydroelectric and pumped storage schemes make up the rest.

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The Loch a' choire ghlais development would be the first pumped storage scheme since work began on a similar development in Wales almost 40 years ago.

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In the 1970s, some pumped hydropower storage was built at existing dam reservoirs to store nuclear power that otherwise went largely wasted at night.

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That is well above the base power load and the surge is supplied by less efficient fossil fuel power generators as well as some peak pumped water storage.

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The scheme named the Captain Clean Energy Project, would see the creation of a new 570MW "low emission" coal power station with CO2 pumped into storage in offshore depleted gas fields.

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