Energy Australia's Managing Director Catherine Tanna briefed the federal government yesterday on the potential for a pumped hydroelectric storage project in South Australia. Tanna says the project would support the delivery of cleaner, reliable and affordable supplies of energy to the state.
Energy Australia partnered with Melbourne Energy Institute and Arup Group over the last 12 months to investigate the project, focusing on using seawater.
Located in the Spencer Gulf of South Australia, the proposed project would have the capacity to produce around 100 megawatts (MW) of electricity with six-to-eight hours of storage. That's the equivalent of installing 100,000 home battery storage systems, but at a fifth of the cost, Energy Australia says.
"Pumped hydro storage using seawater is just one of the innovations we're looking at to increase Australia's supplies of cleaner energy," said Tanna. "The technology works like a giant battery. Its great advantage lies in complementing the shift to renewable energy by providing a reliable store of affordable power."
Last week Tanna said she was "worried" about what will happen to customer's bills after the recent heatwave in Eastern Australia.
"We've seen that customers over the weekend in some places in Australia used 25 per cent more than usual," she said. "In a couple of months when these bills turn up they are going to get a surprise and I am worried about that because I know that the cost of living is a concern for them."
Renewables are the long term solution, Tanna said. The currently cheaper forms of electricity (coal, mainly) will be retiring in the next 20 years is a "reality" and a transition plan to renewables is the way forward to avoid higher bills.
One of Australia's biggest operators of coal-fired power stations, Energy Australia, has come out and said the solution to reducing customers' bills is a transition to renewable energy.
Tanna said on hot days, when demand spikes, a pumped hydro plant can be brought into action in minutes, "keeping the lights on and costs down".
Tanna said while some proposed projects, like interconnectors, tend to shift reliability issues, energy storage, whether in the form of pumped hydro or batteries, "actually solves the problem".
Pumped hydro is a form of hydroelectricity that does not rely on rivers or flowing water. Fresh water pumped hydro has been used for decades in countries including the United States, Japan and China. In 2013 Melbourne Energy Institute and Arup started assessing how the technology could be adapted to Australia's dry conditions using seawater.
"The proposed project for South Australia would not only be the second example of a seawater pumped hydro storage plant anywhere is the world; it would also be the largest," said Stephen Thompson, Leader of Strategy and Policy Advisory for Arup in Australasia.
With pumped hydro, water is pumped from a lower reservoir to a higher one when energy is cheap. Then, when demand for power is high and prices rise, the water is run down again and put through a turbine to generate electricity. Because the water is reused, this process can be repeated.
Energy Australia and its partners are aiming to have a feasibility study done on the project by the middle of 2017. If the project is viable, detailed engineering design work, environmental impact statements, consultation with stakeholders and applications for government approval will follow.
Construction would take around two years, which means the project could be providing peak power to the grid by the summer of 2020.