DRDGold building initial 20 MW solar, 100 MW storage at Ergo gold operation

17th February 2022 By: Martin Creamer - Creamer Media Editor

DRDGold building initial 20 MW solar, 100 MW storage at Ergo gold operation

DRDGold CEO Niƫl Pretorius
Photo by: Creamer Media

JOHANNESBURG (miningweekly.com) – With a view to reducing its carbon footprint as well as addressing the uncertainty of the supply and cost of electricity, surface gold mining company DRDGold has taken a decision to construct a solar power plant and a power storage facility at Ergo, the gold from mine waste operation on the East Rand.

The board of the Johannesburg- and New York-listed company has approved the capital expenditure for the first phase, involving the upgrade of the existing supply line to the Brakpan/Withok tailings storage facility to 88 kVA, the construction of an initial 20 MW photovoltaic plant, and ten power storage facilities of 10 MW each. (Also watch attached Creamer Media video.)

This will be another important thrust across DRDGold’s already far-reaching environmental, social and governance (ESG) spectrum.

“The first phase – that which is going to happen in the near term, as soon as Eskom gives us the go-ahead to do the upgrading of the line, which we believe is imminent – we'll do ourselves,” DRDGold CEO Niël Pretorius told Mining Weekly in a Zoom interview.

“The board's happy for us to do that ourselves. We’re a company that does not have any debt, we’ve got in excess of R2-billion in the bank. This is a project where we think green funding would be really well suited, maybe some sort of a green bond, because of the nature and how it delivers into the ESG aspect, as well as carbon reduction. All of those details we would want to share with the market once we’ve sealed them, and once we know that they are what we think they are,” Pretorius said.

Storage was something that the surface gold recovery company was intent on doing regardless of the incorporation of solar.

“We were going to charge these batteries off the Eskom grid during off-peak periods, and then draw during peak periods. Just the saving of not having to pay the premium for that charge during peak period was going to be enough to justify the storage itself. The storage is even more compelling, financially speaking or commercially than the solar panels themselves but it's a good match and you want them both,” Pretorius added.

Regarding the need for considerable land when going solar, he said: “We have plenty of land. I think DRDGold is probably one of the largest landowners in Johannesburg, with north of 6 000 ha. But there, right next to the Ergo plant, is more than sufficient land where we can build the plant, locate the solar panels as well as the storage facility, which is modular in design. This will be linked to the Eskom grid, and also feed back into the grid, hopefully to ultimately also draw power at some of the other operations against some of the units that go back into the grid. It's a project that's been five years in the making. We were cautious to begin with in terms of the sort of technology that we wanted to invest in.

“The model wasn't entirely convincing initially, but I think we've reached the stage now where both the volatility of supply, the quality of supply and also the pricing of supply – those things have just escalated to a point where you simply cannot wait any longer. The technology has also rapidly improved in the near past.

“The panels now compared with the panels of five years ago show quantum improvement in terms of efficiency, quality and durability. We’re in a high hail belt and so all those factors were important considerations. We're starting out initially with roughly one-third of what the total project design envisages over a longer period of time, and we are setting it up in such a way that we are feeding back into the Eskom grid, not the municipal grid. We could not get the municipality across the line, they wouldn't sign consents, they wouldn't budge. They literally stonewalled this thing, so we had to find a way to get back straight into Eskom and their grid. Hence the 88 kVA line that is going to go into the Eskom substation, at the Brakpan tailings dam. That's the first phase and that enables us because it goes directly into the Eskom grid and then also ultimately takes advantage of the units fed in and drawing those units, being credited for those units, at some of the other operations. In terms of costs, we’re still weighing up the option of doing this off balance sheet by way of some sort of power producer entity.

“The model is just so robust, though. The return on investment is just so robust on the saving aspect only, not even taking into account the fact that you will be reducing the disruption of power supply. We’re turning these numbers over in our heads, deciding how much of it we should be funding ourselves, and how much of the upside do we really want to give away,” Pretorius said.

Mining Weekly: Are you confident of the storage aspect?

Pretorius: Storage was something that we were going to do regardless of whether we were going to do the solar panels, because we were going to charge these batteries off the Eskom grid during off-peak periods, and then draw during peak periods. Just the saving of not having to pay the premium for that charge during peak period was going to be enough to justify the storage itself. The storage is even more compelling, financially speaking, or commercially, than the solar panels themselves but it's a good match and you want them both.

What about also generating green energy at the Far West Gold Recoveries operation?

Sibanye-Stillwater is also looking at various plants across their footprint. I’m not quite sure how much of that is in the public domain. But there, we would be looking at a collaboration. Initially, until such time as that does come to fruition, we would want to draw surplus units back into the grid at Far West. Hence, the reason why we want to tie into the Eskom grid, but that will be what we do until such time as we decide on a collaboration with Sibanye-Stillwater. But we don't have any immediate plans to go solar in the Far West, rather just take advantage of maybe surplus units being fed back into the grid at Ergo.

How green is DRDGold’s valley and what do you have in mind to make it even greener?

The point most often overlooked and we probably don't emphasise it enough is the fact that we don't generate any waste. We produce a metal, we produce gold, but we don't produce waste in the process. In fact, what we do is take waste where it has become either inconvenient, or where it poses a risk, we process it through a process which we believe is sustainable and value-adding and we then store it somewhere else, in a facility that is being run at a different standard and that does not pose the same risk or bring with it the same nuisance that the waste we've removed poses, where we recovered it from. That's one of the features that makes the company unique is the fact that we do not add to the amount of mine waste on the surface of this planet. Secondly, the fact that we've been migrating consistently towards recycled water, and that we have a closed water circuit, so that no water goes to waste other than through evaporation and everything is used and used again, and we can reach the furthest corners of our operation from our central water plant. The reduction in potable water usage has stood us in good stead also in terms of let's call it our environmental value-add or our environmental dividend. The burden that we're imposing in that regard on other users, and the fact that we’re not competing for potable water to the extent that we were ten years ago, I think that that adds significantly to the environmental value proposition that we pursue. What's worse is the fact that recycled water is also a lot cheaper than the water that you would get from Rand Refinery and I think that's the sort of constant theme in many of these projects that we pursue, we really want to try and create an integrated value, if I may use the MBA term. We want to invest in power not only because it's good for the environment, but also because it reduces our risk and it reduces our costs. We developed our centralised water plant and we built the recycled water plant at one of the sewage plants. We did that not only because we want to have a lighter footprint environmentally, but it also costs us less money and it derisks the business. Sustainable development is a wonderful notion and I'm a big disciple of one of the pioneers of sustainable development, Paul Polman, and I've read some of his work quite extensively. I’ve studied it, and if you can achieve that, if you can bring about multi-layered overlapping value, where your investment in the one also impacts or adds to the value in the other capital stocks that form part of the sustainable development suite, that's really how you set your business up in terms of resilience and longevity. That's really key to our thinking that that's really what we want to try and achieve as a corporation.