Bendigo gold miner plans 60MW solar farm on old evaporation ponds

An Australian gold mining company has announced plans for a 60MW solar farm to be built on former evaporation ponds used for underground mining near the gold mining centre of Bendigo in central Victoria.

GBM Gold said on Wednesday that the solar farm – one part of which will be “floating solar” – was planned for 174ha of the Woodvale Evaporation Pond Complex, a series of “redundant” evaporation ponds that are a “compelling candidate” for a solar plant.

The ponds, about 10km north of Bendigo, were used to evaporate groundwater historically pumped from underground gold mining activities and had been marked for a return to agriculture.

GBM says it has a better idea: “This is an ideal re-use of a redundant facility as the ponds enjoy excellent sun exposure, are not readily visible to adjacent residences and are located close to where the power is needed,” the company said in a statement.

“Construction of a Solar Power Plant, as an alternative to returning the site to agricultural use, can be implemented in a short timeframe giving immediate benefit to the entire Bendigo region.”

And, it says, the City of Greater Bendigo has a goal of 100 per cent renewable energy generation from local and regional sources, and the Woodvale Solar Project could be a significant step forward in achieving that goal.

The evaporation ponds were used until 2016, when the state government then decided to direct the water to a water treatment plant.

The idea appears to be at the early stages.

GBM Gold plans community consultations, but says it has been told by local network operator Powercor that the Woodvale Solar Power Plant could be connected to the existing 66 kV sub-transmission loop in Bendigo at the Eaglehawk Zone Substation. A new substation to be built on the site of two of the rehabilitated ponds.

CEO John Morrison said the idea came about after talking to Bendigo council about plans for a small pumped hydro installation in one of the old gold mines, and the need for solar to power it. “It’s a superb site,” he told RenewEconomy.

Morrison said the project would likely get built over the next 2 years but GBM would likely bring in a joint venture to move it forward to construction and commissioning.

The company says the solar project will utilise Ponds 1A, 1B, 2, 3, 6 and 7 and the existing infrastructure at Woodvale (see image above).   Pond 1A will be retained as a pond and operate as floating solar, and that will enable containment of all rainfall on the site.

Ponds 1B, 2, 3 and 7 will have their spillways removed so that they do not retain water.  A standard solar system will be installed on these ponds.

There is also considerable rehabilitation work to be done, including removing salts and metals from the base of four of the ponds, stockpiles of contaminants from a previous reconstruction of three ponds, and other work.

“The work required to prepare the complex for the development of a solar project is less than that required to return it to agriculture,” the company says. “The ponds are designed to maximise the amount of sunlight impinging on them with only screening around the property.”

GBM Gold purchased the Bendigo Goldfield, Australia’s second largest goldfield, several years ago, with plans to create some large open pit operations.