One hundred percent renewable energy to power Australia? It sounds like a pipedream—unless you were in the audience at the Bermagui Institute Dinner at Il Passagio on 21 September to hear Andrew Blakers, Professor of Engineering at the Australian National University, speak about pumped hydro energy storage.
When talk turns to renewable energy lately, the next question is always storage. There’s no question that Australia can harvest massive amounts of wind and sunshine, but how to store excess energy for when the wind doesn’t blow, the sun doesn’t shine? Banks of Tesla lithium-ion batteries? Expensive, and with limited lifespans.
But anything that stores energy is a battery. And Blakers and his team have identified 22,000 potential sites in Australia for pumped hydro energy storage (PHES), all outside national parks and urban areas. There’s an excellent site near Bombala. Fast track development of several Gigawatt-rated sites could be complete by 2022 in time to stabilise the grid as Liddell and other coal-fired power stations close.
Put simply, two reservoirs, sized between 10 and 100 hectares, are built at different altitudes—say at the top and bottom of an escarpment. They are connected by a pipe with a pump and turbine. When there’s plentiful electricity (from solar or wind), water is pumped up to the top reservoir. When power is needed, water is allowed to flow back down, turning the turbine.
Malcolm Turnbull’s ‘Snowy Hydro 2.0’ is a PHES system on a grand scale. The difference with Blaker’s PHES is that the reservoirs will be ‘off-river’—they can be built anywhere there’s suitable ‘head’, the difference in altitude between reservoirs.
Annual water requirements of a PHES-supported 100% renewable electricity grid would be less than one-third that of the current fossil fuel system.
Of the 22,000 sites that Blakers has identified, only a few dozen will be needed to support a 100% renewable energy system for Australia. ‘We found so many good potential sites that only the best 0.1 per cent will be needed,’ said Blakers. ‘We can afford to be choosy.’
The plan also requires strong interconnection of the electricity grid between states and territories, using high-voltage power lines spanning long distances, to take advantage of varying weather conditions across the country at any one time.
On the night, Blakers got a grilling from the floor. MC Doug Mein tried to close down question time three times but the audience kept firing them off. It sounded too good to be true. Lots of crossed arms around the room, studied frowns. But he had an answer for every question. It stacks up.
I had a copy of a press release from Blakers in my inbox; he’d sent it out at 5.56 that morning. Apparently he’d done interviews all day, then driven down to the coast to keep his appointment with us at Il Passagio.
Obstacles? The coal lobby will run interference. ‘I don’t know how they look their children in the eye,’ said Blakers.
See more at http://re100.eng.anu.edu.au.