The Australian National University has completed a global audit of potential pumped-hydro finding 530,000 potential sites for pumped-hydro energy storage.
The report found that zero-emission grids of the future would mainly rely on solar photovoltaic (PV) and wind technology, with support from pumped-hydro storage and extra high voltage transmission between regions. Solar PV and wind constitute the largest and second largest respectively annual global net capacity additions.
Lead researcher Dr Matthew Stocks said that the the prospective short-term off-river pumped-hydro energy storage (STORES) sites combined had a global potential storage capacity of 22 million Gigawatt-hours (GWh) - which is hundreds of times more than the amount needed to support a global 100 per cent renewable electricity grid.
"Only a small fraction of the 530,000 potential sites we've identified would be needed to support a 100 per cent renewable global electricity system. We identified so many potential sites that much less than the best one per cent will be required," said Dr Stocks.
The team from the ANU developed a series of algorithms to locate potential sites for off-river hydro, with each site containing upper and lower reservoir potential.
Co-researcher Professor Andrew Blakers said off-river pumped-hydro storage typically delivered maximum power from five to 25 hours, depending on the size of the reservoirs.
"Pumped-hydro energy storage can go from zero to full power extremely quickly - it takes only a few minutes," he said.
Professor Blakers said annual water requirements of an electricity system built primarily on solar PV and wind would be much less than a fossil fuel system because wind and PV do not require cooling water.