Abandoned mine to be converted into world’s first large-scale PHES

Kidston, Australia, became one of the 50,000 “orphaned mines” of the country – after being a mining town for a century.

Leading energy and environmental consultancy, Genex, plans on reusing the craters left by the mining activities for the first pumped hydroelectric energy storage (PHES) system in the world, combined with an integrated solar farm.

Simon Kidston, Executive Director of Genex, said: “We’re not aware of any examples anywhere else in the world where there is a large pumped storage system, or any efficient storage mechanism, with a renewable generation component attached to it – not on the scale we’re talking about.”

Pumped hydroelectricity represents 99 per cent of the industrial-scale energy storage market globally as it allows solar and wind energy to be stored and then redistributed.

Genex is building a 50 MW solar farm, to be completed by the end of 2017, and will generate enough energy to power 27,500 homes – 145,000 MWh.

A 300 MW PHES will then be built – with two reservoirs at different heights to allow water pumping between them - and will work for seven-hour cycles every day.

The water flows from the higher reservoir – where electricity is sourced from the grid pump water – to the lower when energy demand is more important, driving a turbine in an underground powerhouse, which converts it to electricity.

PHES already exists, but are largely based on river facilities.

Genex’s system will be the first large-scale “off-river” system, allowing the cycles to consistently run in a closed loop and minimise environmental impact.

Kidston said: “We realised environmental issues would prevent damming of rivers in mountains, where most hydro is located... And we also wanted to pursue a low-cost development strategy.”

The company is saving hundreds of millions thanks to the reuse of the existing mining site infrastructure and permits.

Kidston expects his project to be beneficial to the local community, being an “enduring productive economic” use for the land which was “extensively disturbed” by mining.

Prof Andrew Blakers, director of the Centre for Sustainable Energy Systems at the Australian National University, said: “Pumped hydro is by far the cheapest and most mature storage technology... [Genex’ PHES is] a good model, particularly when combined with co-located PV and wind... However, there are hundreds of sites with much larger height differences between top and bottom reservoirs throughout settled Australia, so it’s not the only model.”