This audio is brought to you by Wearcheck, your condition monitoring specialist.South Africa's many underground mines can be used as batteries that store the clean electricity that the water descending for cooling can provide.At the same time, the local community could end up with a utility that supplies them clean water along with a store of cheap and reliable green energy.While the chemical battery systems for the storage of electricity last for ten to 15 years, pumped hydro longevity from repurposed mines is in the 50-year to 100-year category.Moreover, the bulk of the capital required for the building of a pumped hydropower facility in a mine will likely go into local pockets.The local community will also likely supply the labour to keep the mine operating as a hydro facility and also probably provide the human resource for the construction of the upper and lower reservoirs and the penstock.Repurposing mines could also help South Africa to advance along the road to energy independence and possibly also eventual energy exportation, while simultaneously ensuring optimum scarce water use.South Africa, which already has hydropower installed in many of its deep-level mines, is probably better positioned than most countries to take advantage of pumped hydropower technology, which provides a cost-competitive energy storage solution.Moreover, it fits hand-in-glove with South Africa's superior sun and prime wind power to pump the closed-loop water back to surface for renewed release.Already, there are 50 mine sites that make use of the kinetic energy gravity gives to the falling water, which allows it to spin wheels from which electricity is generated with the help of Pelton technology installed in the 70s and 80s.Included among these mine sites are some of the world's deepest operating turbines, with heads of up to 1 890 m, putting South Africa in pole position to take full advantage of the global renewable energy plus storage trend in next to no time.Hugely advantageous is that most of the deep-level mines in all the provinces where steps are being taken to install chemical battery storage, including in South Africa's Gauteng, Free State, and North West provinces.South Africa already knows a great deal about pumped hydro thanks to Eskom's Drakensberg, Palmiet, Ingula, Steenbras and other pumped storage schemes that serve as massive water batteries.Now it has the added opportunity of turning even discard mines to further account.The water will be pumped up when operations have excess renewable power and allowed to gravitate back down the mine when electricity is needed. This reduces storage capacity when compared with lithium batteries and even hydrogen storage.It is a smart solution based on the physical assets that are under-utilised and provides a cost-effective solution for the whole South African package.These are among the very many insights provided by Karst Hydro MD Guy Richards and Karst operations director Jessica Giger, who spoke to Mining Weekly in a Zoom interview. (Also watch attached Creamer Media video.)Karst is a project development company that specialises in underground pumped hydroelectric energy storage project and essentially what that means is that the company repurposes mines for energy storage.Project definition services for mine owners wanting an independent source of power are there for the taking.While battery energy storage systems are being procured by the Department of Mineral Resources and Energy, mine owners can double as long-life water utilities by reutilising their assets that already have access to power transmission networks, environmental management models, and water use licences.What level of electricity contribution are Pelton wheels making in mines?They started to constructing the Pelton wheels working in South African mines in1978 and they are very reliable. They are used primarily for energy recovery. The other feature of on-site storage is that it gives the mine ...