Water research has potential to unlock enough renewable energy to power Australia

Posted 4 September 2017

Pumped hydro storage could be the key to Australia achieving 100% renewable electricityPumped hydro storage could be the key to Australia achieving 100% renewable electricity by the 2030s. 

An Australian National University research team, lead by Engineering Professor Andrew Blakers, received $449,000 in funding from the Australian Renewable Energy Agency to produce a nation-wide atlas of potential off-river pumped hydro storage sites.

“The research project has three aims: to find all of the promising pumped hydro sites in Australia, to develop a publicly available cost-model so anyone can get a reasonable idea of what any particular site will cost to develop, and to look at 100% renewable electricity scenarios involving wind, solar PV, pumped hydro and stronger interstate interconnection,” Blakers said. 

Now less than a year away from producing an in-depth, public cost-model to aid implementation, the project has thus far identified thousands of appropriate sites, offering huge potential for low cost energy storage.

“We’ve found 6000 sites so far, and expect to have 10,000 sites by the time we finish the study. It’s a vast number of sites and 99% of them are off-river. Because there are so many sites, we can be choosy with what sites we utilise,” Blakers said. 

“The criteria we choose are firstly that the minimum head is 300m – that’s the height difference between the upper and lower reservoirs – which is double the head of the largest existing pumped hydro storage site in Australia. When you double the head, you double the energy and you double the power, but you don’t double the cost of the storage. 

“Secondly, the energy storage of each site is in the range 1-100GWh, which corresponds very roughly to about 1-100GL of stored water. Between these two criteria, we can reduce the vast number of potential sites to something manageable.”

Pumped hydro has much larger energy storage potential than South Australia’s Tesla battery: “We expect to find 30,000 to 40,000GWh of storage sites, which is about 100 times more sites than we actually need to support a 100% renewable electricity grid,” Blakers said. 

Results of the project show that the cost of a nation-wide renewable electricity system, supported by pumped hydro storage systems, is not only cleaner, but also cheaper than current wholesale electricity production. 

“We’ve finished a study of the south-west interconnected system, which is Perth’s electricity system, and we’ve also finished a study of the National Electricity Market,” Blakers said. 

“The key outcome from the National Electricity Market study is that the all-in cost of a fully reliable, 100% renewable electricity system is less than the current cost of wholesale electricity.”

Blakers said the huge amount of appropriate and cost-effective sites also removes issues relating to environmental and hydrological concerns that may stand in the way of implementation. 

“There is nothing mysterious about it. There are no rivers, no national parks, no urban centres involved. And there are so many sites that if there are environmental, geological, heritage or hydrological concerns, you just walk over the hill and there’s another site,” he said. 

“The great thing about pumped hydro is that there are not many challenges. The technology is completely off the shelf. There’s 160GW of pumped hydro around the world. There is nothing to invent – it’s just about choosing which company you’ll go with.”

The research team has already completed its initial survey of South Australia, Tasmania, Queensland and the Australian Capital Territory, and is now working on New South Wales, Victoria and Western Australia, expecting to complete all states by the end of September.

“We hope to have the cost-model in early November in a beta version. We will then go back and do the whole thing again in more detail using the cost model to discriminate between potential sites and rank them into bands,” he said. 

“Then people will be able to go to a district that they are interested in, find the A or B ranked sites and get a reasonably good idea of what any of those sites would cost before they have to engage a company to do a feasibility study for $100,000. 

“The idea is to make the barrier to entry as low as possible, so we can go a long way down the track before anyone has to spend any money.”

Access the initial state and territory surveys here

Interested in finding out about the latest innovations coming out of the ACT? The ACT Water Leaders Dinner and Awards will take place on 7 September. Click here for more information.