Pumped hydro study backs renewables boom

Posted 17 November 2016

Pumped hydroOff-river pumped hydro energy storage could help Australia reach 100% renewable energy generation at very competitive prices, an ANU-led study has found.

Researchers are scouring the country for potential sites for short-term, off-river pumped hydro energy storage (STORES) and have found “unlimited numbers” of sites.

“There's no shortage of sites off-river … that's what we found all the way from North Queensland to South Australia and everywhere in-between,” said lead researcher Professor Andrew Blakers.

“There's enormous opportunities for those who have the capability to build wind farms, solar farms, high-voltage transmission lines and pumped hydro systems.”

Pumped hydro storage is widely used internationally but it's been largely ignored in Australia.

“The reason people keep overlooking pumped hydro is because allegedly Australia is flat and arid and there's no more rivers to dam so we can't have any more hydro electricity than we've got at present,” Blakers said.

“But what people are overlooking is that you don't need a river to have pumped hydro storage – you just need a hill (that's not inside a national park) where you can put a hectare-scale reservoir on the top, another one on the bottom with a pipe in between to make the same water go around and around in a circle.”

As part of the Atlas of Pumped Hydro Energy Storage Study, numerous sites with height differentials between 300 to 700m have been found in every Australian state, with the possible exception of Western Australia, Blakers said.

“The bigger the head the lower the cost [of generation] because if you double the head then you double the energy storage, you double the power capacity but you don't double the cost,” he said.

Based on conservative modelling of power prices and current technology, the study has found STORE could make renewables extremely competitive in Australia.

“We're talking about 8-9 cents/kWh for a clean, green 100% renewable electricity industry compared with the current cost of wholesale electricity in Australia, which is about 6 cents/kWh …  so we're not very far away at all from direct competitiveness and that's with 2016 prices,” Blakers said.

“It's certain that wind and photovoltaics are going to get cheaper so we're projecting that by about 2025 renewables could cost 7 cents/kWh for a fully stable system.”

The modelling did not include any “heroic assumptions” Blakers said, and only considered the four mainstream renewables technologies that are deployed in more than 100gW quantities around the world.

“These are off the shelf – costs are well-defined and even at today's prices, without any allowance for future cost reductions, it's looking very interesting,” Blakers said.

“We don't have to be aggressive because the numbers speak for themselves at today's prices.”

The study is due to finish in June 2018 and Blakers said it would send a strong message to those who believe renewables are unviable.

“They need to do their homework before they jump on the end of a microphone and pronounce that renewables can't do it because it's plainly not true,” he said.