Miners are meant to rehabilitate old mine sites. An attractive alternative can be to turn them into money-making concerns by means of pumped hydro.
On 27 November Sophie Vorath wrote that the first phase of the Kidston Renewable Energy Hub – a world-first solar and pumped hydroelectricity hybrid – would be generating power for the grid within the next 10 days, which means it started to operate while the votes were being counted in the Queensland election.
There’s more from ARENA, which contributed funding, at Renewable, reliable energy from an old, abandoned mine site? That’s gold
The first phase comprises a 50 MW PV array, to be followed by another 270 MW of solar PV and pumped hydro energy storage capacity of 2000 MWh by the time it is completed, in early 2021.
When complete, the Kidston Renewable Energy Hub will provide around 783 gigawatt hours of renewable energy per year, enough to power around 140,000 average Australian homes via a new transmission line.
“That transmission line will effectively hook into Townsville and Cairns and all of that northern part of Queensland will be fed off the electricity we generate,” Genex Executive Director Simon Kidston says.
Here are the actual storage sites:
And here is the actual solar array:
- The Queensland government is building a second transmission line for Stage Two, which will connect the hub to the National Electricity Market.
The project is also a job-spinner. Stage one already has 88 people on site, with stage two expected to employ 500 people when construction begins next year. The Northern Australia Infrastructure Facility is also considering the project for funding.
The developers see the hydro project as a peak power generator as well as a water battery. When the planning was done the price of gas was $2-$3 a gigajoule, now it’s $8-$10 a gigajoule.
Genex Executive Director Simon Kidston, great-great grandson of William Kidston, the 17th Queensland Premier, after whom the gold mining town was named, said that there were at least 5-10 sites around Australia that would be suitable.
One such is emerging at the 47-year-old Kanmantoo copper and gold mine, which is located about 50 kilometres south-east of Adelaide. Earlier this year consideration was being given to extending the pit underground.
A recent AFR article (pay-walled) says:
- A drop of close to 250 metres already separates Hillgrove’s tailings dam from the bottom of the Kanmantoo mine pit, and McClare says that distance will stretch to 427 metres after a further 18 months of mining.
The site is only 3 km from the Victorian interconnector, and the prospect now is to turn the mine into a hydro project to arbitrage volatile power prices:
water is pumped uphill to a higher reservoir when electricity prices are low, then released to the lower reservoir (via energy-creating turbines) when prices are high.
The strategy would be simply to take electricity off the grid when the spot price was low, and sell back in when it’s high. Of course this activity would over time, and especially if it is extended, even out the prices at both extremities, as well as stabilise a grid heavily committed to wind and solar. The development cost could be half that experienced by a ‘conventional’ pumped hydro.
a hydro facility could be operating at Kanmantoo by 2021, although any final decision would be weighed against the potential to extend copper mining beyond the current permit to 2020.
ANU’s professor of engineering Andrew Blakers led a study which identified 22,000 sites across Australia that were suitable for pumped hydro and had an elevation change of at least 300 metres.
A number of mine sites were included, but not Kanmantoo, because it was then too shallow. Two of Australia’s most famous mining towns, Kalgoorlie and Mt Isa and , were nominated by Blakers as having particularly good potential for pumped hydro sites. There were two or three mine-based potential pumped-hydro sites near Mt Isa, including the old uranium mine at Mary Kathleen. Mt Isa is of particular interest because it uses a lot of power and is not connected to the grid.
Blakers said the famous Kalgoorlie Superpit also had huge potential as a pumped hydro location, with its depth already beyond 600 metres. He said:
“The Kalgoorlie SuperPit, plus the wind and sun that is available, means that WA could readily go to 100 per cent renewables.”
Then there is Sanjeev Gupta with Zen Energy in Whyalla (pay-walled):
ZEN Energy, the clean energy company controlled by British billionaire Sanjeev Gupta, has approved a $700 million solar, battery and pumped hydro storage project to deliver power to Mr Gupta’s Liberty OneSteel works in Whyalla, South Australia,
The “green steel” project includes 200 megawatts of solar panels on the former Arrium steelworks at Whyalla and nearby council land, a 100 megawatt/100 megawatt hours battery at Port Augusta, 100 MW of “demand response” and a 120 MW/600 MWh pumped hydro storage facility in an old iron ore mine near Whyalla.
It comes with in-principle agreement to add another 480 MW of solar capacity as the market requires, which could cost another $900 million-$1 billion, and plans for waste heat and gas co-generation that are still being finalised.
I’m not certain it involves an old mine site.
Old mine sites are also being considered in Ontario, Canada, and in Germany, but Australia is at the leading edge, and Genex is partnering with tier-one companies to develop their project, including US PV heavyweight First Solar and German-based inverter giant SMA. Genex has also been helped by a 20-year agreement with Queensland state-owned energy company, CS Energy, to buy the power for 20 years, and has struck a 30-year agreement with state-owned Ergon on grid connection, all concluded under the ‘do nothing’ Palaszczuk government.
Contrast the LNP Nicholls proposal not to waste any more money on renewables and to initiate a northern coal-fired power plant project within two months of gaining office.