Solar and battery plants for remote gold mines

The processing plant at a gold mine doesn’t stop for the night. Ore keeps moving through the crushers and mills, the pumps keep running, and on a remote site every one of those kilowatt-hours usually comes from engines burning fuel that arrived by truck. A handful of gold mines have already changed that. Their records are now long enough to learn from, and they don’t all point the same way.

Three gold mines, three designs

Fekola, Mali. B2Gold added a solar and battery plant to the heavy-fuel-oil power station at its Fekola mine. The first phase, 30 MW of solar and a 17.3 MW battery, reached full production in 2021. B2Gold reports that it saved around 13 million litres of heavy fuel oil in 2024. At its best, up to three-quarters of the site’s daytime power came from the sun. B2Gold has since built a second phase.

Agnew, Western Australia. Gold Fields went for a mix. The Agnew microgrid combines 18 MW of wind, 4 MW of solar and a 13 MW / 4 MWh battery, with gas and diesel engines as backup. In its first full year of data, July 2020 to June 2021, 54.6% of the mine’s energy came from renewables. Monthly figures ranged from 47.2% to 58.9%.

Bellevue, Western Australia. Bellevue Gold’s power station, run by Zenith Energy, has 27 MW of solar, 24 MW of wind and a 15 MW / 33 MWh battery. In 2026 it ran for 155 hours in a row with every engine off. That is six and a half days of a working gold mine on sun, wind and storage.

What they teach

Solar on its own hits a ceiling. Fekola shows how far daytime solar can go: most of the daytime load. But the sun sets, and the processing plant doesn’t. Solar alone mostly saves fuel in daylight hours.

A second source, or a bigger battery, lifts the ceiling. Wind blows at night. With wind in the mix, Agnew got past half its energy from renewables with only a small battery. Bellevue added both wind and a battery measured in hours. That is what let it switch the engines off for days rather than minutes.

The battery’s job sets its size. A battery that only steadies the system while clouds pass can be small compared with the solar field. A battery that has to carry the plant after dark needs hours of storage, and its control system has to keep the site grid stable without engines running. That is a design question as much as a purchase.

Mine life sets the ownership model. B2Gold owns Fekola’s plant. Bellevue buys its power from Zenith, which owns and runs the station. A mine with eight years left looks at a twenty-year asset very differently from a mine with twenty-five years ahead of it.

What a study for your mine needs

You don’t need a full design to get a first answer. You need five things:

• Fuel. A year of fuel invoices, with the price you actually pay on site, not the terminal price.
• Load. Hourly or daily power use of the processing plant, camp and mine, and how it changes with throughput.
• Hours to cover. Whether the target is a daytime fuel saver, engines off for part of the day, or the night as well.
• Land. Flat or gently sloping ground near the power station, and who owns it.
• Mine life. The years left in the plan, which decides between owning the plant and buying the power.

Our work model sizes the battery from the hours after sunset the site has to cover. It starts at 12 hours. Capacity in kWh is the average load times those hours, divided by 0.9 for the usable part of the battery.

What the numbers can look like

On our home page we show a modelled estimate for a 10 MW solar and battery plant at a remote gold mine: fuel cost 42% lower in the first year. With the work model’s default case of 2,000 litres of diesel a day at US$1.10 a litre, payback is about 3.5 to 5.4 years. These are model figures, not results from a GoSí plant. Your fuel price and load will move all of these.

How GoSí works with gold mines

GoSí does not build the plant itself. We put the project together:

Feasibility. A first look at the site, the load and whether a plant fits the operation.

Procurement partners. The partners who supply and build the equipment.

Available subsidies. The subsidies that apply to the project.

Green mine finance. Finance for the plant, whichever way you own the power.

Custom design. Our EPC partners design and build the plant for your load, land and conditions.

Two ways to own it: Own & operate, where you buy and own the system, or Land + PPA, where you provide the land, our partners build the plant and you buy the power under a power purchase agreement.

See also:Replacing diesel generators at a remote mine with solar and batteries