The Australian Renewable Energy Agency (ARENA) is funding projects that look into the cost-effective on-demand delivery of renewable energy from short-term off-river pumped hydro energy storage (STORES) sites.
In the Atlas of Pumped Hydro Energy Storage Study the Australian National University will partner with ElectraNet and VTara Energy Group to map STORES sites across Australia that could deliver reliable and clean energy storage feeding into the grid on demand.
According to ARENA chief executive officer Ivor Frischknecht, the vast majority of existing large-scale energy storage comes from large on-river hydroelectric dams, such as those in Tasmania and the Snowy Mountains.
There is limted potential for further large-scale hydroelectric systems in Australia. However, there are hundreds of smaller, environmentally suitable sites for STORES.
STORES consist of pairs of reservoirs that are separated by an altitude difference of between 300 – 900 metres. Joined by pipes, water is circulated between the upper and lower reservoirs in a closed loop to store surplus energy by pumping water to the uphill storage reservoir, which then can be use to generate power on demand.
Professor Andrew Blakers from ANU said that the low cost and technical maturity of STORES could allow solar photovoltaic and wind energy to reliably reach penetration levels above 50% and push towards 100% renewables.
A current example for this is a project by Genex, which has just completed a feasibility study of the Kidston pumped-storage project. Supported with up to $4 million from ARENA, the company aims to convert the former Kidston Gold Mine in North Queensland into a giant battery that potentially could feed up to 330 megawatt of power into the grid.
Some of the energy could be sourced from a 50 megawatt solar farm that Genex is developing at the Kidston site.
If Genex can reach financial close, it will start construction of the Kidston pumped-storage project - potentially providing a blueprint for other large pumped hydro storage projects at disused mines.