Pumped hydro storage could deliver Australia an electricity grid supplied by 100 percent renewable energy says a new Australian National University (ANU) study .
The report comes as political leaders battle over the future of clean energy targets, power prices and the issue of wind and solar power in the nation’s electricity mix.
“With Australia wrestling with how to secure its energy supply, we’ve found we can make the switch to affordable and reliable clean power,” said lead researcher Professor Andrew Blakers from the ANU Research School of Engineering.
The researchers found a zero-emissions grid, utilising solar and wind resources backed by pumped hydro energy storage (PHES), would eliminate the need for coal and gas-fired power generation.
Pumped hydro energy storage accounts for 97 percent of all storage worldwide, but the technology has been largely ignored in the debate over securing supply of large-scale renewable energies in Australia Professor Blakers said.
Solar PV and wind energy have become the dominant sources of new generation globally. In 2015, they provided half the world’s new generating capacity, and in recent years nearly all of Australia’s new installed generation capacity.
Meanwhile, Blakers said, “most existing coal and gas stations will retire over the next 15 years, and it will be cheaper to replace them with wind and solar PV.”
Under ANU’s scenario, the levelised cost of energy (LCOE) of a 100 percent fully-stabilised grid powered with renewables would be around AU$75/MWh – cheaper than new coal and gas power.
Backed by a $450,000 grant from the Australian Renewable Energy Agency (ARENA), the ANU is mapping hundreds of potential short-term off-river pumped hydro energy storage (STORES) sites along the east coast from North Queensland to South Australia and Tasmania.
STORES sites are pairs of reservoirs or dams, ideally located in hilly country and separated by an altitude difference of between 300 and 900 metres. The bodies of water are joined by a pipe, along with a pump and turbine system. On sunny and/or windy days when electricity generation in high, water is pumped from the low reservoir to the high one. Conversely, at night, or when conditions are such the energy is needed, the water runs back down through the turbine, providing a constant stream of power.
Dr Matthew Stocks from the ANU Research School of Engineering said STORES needed much less water than power generated by fossil fuels and had minimal impact on the environment because water was recycled between the small reservoirs.
“This hydro power doesn’t need a river and can go from zero to full power in minutes, providing an effective method to stabilise the grid.”
Read the Summary and Full Report on the ANU team’s findings.
