Although Gauteng dwellers have tended to dismiss wind as a renewable energy provider in this region, some are now being blown away by the gusts that puff across our far-stretching gold reef.

“I thought the wind didn’t blow up here,” interim Gold Fields CEO Martin Preece confessed this week during question time at the Johannesburg- and New York-listed company's environmental social and governance (ESG) presentation.

But a tall meteorological mast set up at the long-life mechanised South Deep gold mine is pointing to the opportunity to erect ten 3 MW to 4 MW wind turbines, giving a potential additional 30 MW to 40 MW of renewable energy capacity at a cost of R1-billion. (Also watch attached Creamer Media video.)

Thes wind energy generators will augment the 50 MW of sun energy that South Deep is already generating, at a capital cost (capex) of R715-million.

Interestingly, South Deep’s solar power is doing so well that it will slash R160-million to R170-million off the mine's electricity bill this year.

“If you take the capex out of it, we’re generating electricity at just under 10 c per kilowatt hour at South Deep,” Preece disclosed. That is something like 8 % of what is paid to Eskom for power from the national grid – and this netting of valuable renewable energy is being achieved along South Africa’s historic Witwatersrand gold basin, near the Far West Rand town of Westonaria.

What's more, South Deep’s spectacular solar project was carried out in-house, with the capital cost of R14 300 a kilowatt being absorbed and the margins destined to be put back in the business.

Before Gold Fields embraced energy cleanness and greenness, 93% of its emissions related to coal-fired electricity, resulting in a major need to source alternatives to grid power from Eskom to meet a 30% net emission reduction by 2030 and net-zero by 2050.

“As we invest in those wind turbines, we’re aiming to get off the grid and eventually at the tail-end, which is not in the capex yet, we would look at putting in batteries, or some other storage solution in place,” said Preece. The “some other storage solution” could be interesting because during a media briefing at the Investing in Mining Indaba in Cape Town in February, Preece said in response to Mining Weekly: “We’ve got hydrogen on our radar screen.” Interestingly, a recently released study by independent risk management and assurance firm DNV found that hydrogen has the advantage of relatively cheap storage for each kilowatt hour stored, and storage can be scaled up significantly to increase the discharge time for a given discharge rate. Hydrogen can be produced in seasons with excess electricity generation from renewables and then converted back to electricity during periods with reduced wind and solar availability. Moreover, hydrogen can be stored for a day, a week, a month, a year or years.

TARGET IS TO GET OFF NATIONAL GRID

South Deep’s ultimate aim is to get off the grid, because that is the way it can ensure business continuity, and meet the commitments it has made to get its business carbon neutral.

Questioned by Noah Capital mining analyst Rene Hochreiter on the possible introduction of gas from Mozambique, Preece said: “The challenge is the distance it has to come from Mozambique.”

Hochreiter’s question was prompted by Gold Fields’ inclusion of gas in its energy mix at its St Ives gold mine in Australia.

Said Preece: “Because gas is mined in the northern part of Western Australia, our mines get that gas at a discounted rate to even the rest of Australia.” The gas line runs down from north to south, which makes it convenient for the St Ives mine, and also a bit cleaner. But not withstanding that, Gold Fields is intent on moving St Ives away from gas and focusing on solar, wind and batteries within a microgrid framework.

“We want to get away from gas eventually. St Ives is a long-life asset. That’s the horse we’re backing as a tier-one asset in Australia in which we believe investing the right mone...