Mines’ demand for hybrid energy increases

28th February 2020 By: Mc'Kyla Nortje - Journalist

Mines’ demand for hybrid energy increases

LIGHT IT UP The Aggreko power project at Banro Resources

As the mining industry is continuously striving for sustainable extraction – and with high electricity costs and environmental impact as key factors – power provider Aggreko has seen increased interest in its hybrid energy microgrids, says Aggreko Africa MD John Lewis.

Since launching the offering in 2017, Aggreko has signed three long-term hybrid power contracts – two in Africa and one in Australia, all for off-grid gold mines, he adds.

“Our first mining hybrid power contract was signed in 2017 for a gold mine in Eritrea, and last year we signed our second project for Gold Fields Australia’s Granny Smith gold mine.”

The Granny Smith thermal gas power solution by Aggreko includes the delivery, installation and operation of an additional 8 MW solar farm and 2 MW of battery storage, all of which will be operational next month.

The new hybrid power system is estimated to reduce the mine’s fuel consumption by about 10% to 13% and its carbon dioxide (CO2) emissions by about 11%.

Aggreko’s latest project for Resolute Mining will include the installation and operation of a 70 MW hybrid solution that comprises a 40 MW thermal gas, 20 MW solar and 10 MW energy storage solution.

The 70 MW hybrid solution will reduce the mine’s total cost of energy by 40% and its CO2 emissions by about 20%, explains Lewis.

With the mining industry estimated to account for about 6.2% of the total global energy consumption, implementing measures to address its carbon footprint have come under the spotlight, says Lewis.

“The reliability of renewable-energy sources is a constant challenge for mining companies looking to integrate clean energy into operations, as unexpected disruption to the power supply can have significant cost implications for them.”

He points out that hybrid solutions, which provide combined solar and thermal power, optimised with batteries, allow for reliability of supply, thereby ensuring that productivity is unaffected while supporting efforts to reduce overall CO2.

“Hybrid power solutions can be up to 30% cheaper than using only thermal generators.”

Service Solutions

Lewis notes that, with the reimplementation of load-shedding in South Africa, Aggreko can offer mining companies that depend on the grid reliable backup or prime power to avoid downtime, with no capital outlay.

He adds that the company is providing this service for a mine in the Democratic Republic of Congo.

“We provide the mine with the assurance that whenever there is a power outage, we can take over the power supply. “This particular backup solution will save the mine $100-million a year by avoiding outages, which would normally shut down all mine processes for hours.”

However, Lewis stresses that the integration of solar into a mine’s energy mix necessitates a trade-off.

“While you reduce the fuel costs to zero, which usually accounts for two-thirds of your operational costs paid over the life time of the asset, solar needs an initial capital investment double that of the usual initial capital expenditure (capex) required for nonrenewables. “Mining companies then need to seek external funding, rental solutions or a mix of these.”

He explains that Aggreko’s renewable microgrid and hybrid power systems can be funded in several ways, including zero capex, where Aggreko funds the thermal and battery storage on its balance sheet and assists the customer in finding a third party to finance the solar portion.

This means that South African gold mines do not necessarily need to have the capex to adopt renewables into their energy mix, adds Lewis.

Meanwhile, cost concerns are not the only issue locally, as unreliable grid capacity can also significantly impact on production, says Lewis.

Mines can secure a reliable cost-effective alternative by working with a power partner through a rental solution, ultimately enabling them to become independent of the grid and avoid the impact that the electricity tariff increases have on their business, he adds.


As the adoption of renewables increases, so does the complexity of balancing supply and demand, notes Lewis, adding that sophisticated digital systems and controls are needed to integrate an ever-wider set of energy sources while maximising efficiency and ensuring stability.

He explains that Aggreko acquired energy storage company Younicos in 2017 to form part of its microgrids and storage solutions team.

“The team added two important capabilities to our portfolio: plug-and-play battery energy storage systems, and a highly advanced software suite that ensures the smooth interlay of all generation assets, guaranteeing the highest level of resilience and efficiency for microgrids.”

Additionally, the company has rolled out its Aggreko Remote Monitoring across its global fleet.

Remote monitoring and control systems are designed to control large or complex facilities and/or equipment, such as generators, with some degree of automation.

“The remote monitoring enables us to collect data from the monitoring and GPS software installed to see how to improve fuel and equipment efficiency, respond to changes in demand and take immediate action if something breaks.”

Meanwhile, Lewis notes that it is still unknown what the mining sector will look like in 2030; however, it is certain that the industry will be markedly different from the current one.

He concludes that, rather than view this transition with scepticism, “we should embrace the opportunities that are a by-product of this change. With the chance to reduce carbon emissions, improve margins and drive efficiency as a result, what’s not to like”?