Shifting the energy profile of Africa’s mining sector to a sustainable footing
By Cane O’Neill – Technical Manager, Bergen Engines South Africa
How can one of Africa’s largest industries shift to a sustainable power footing – and what are the necessary power infrastructure components to make such moves viable?
Africa’s raw materials from rare earth elements, battery materials and traditional metal and ore mining are one of the continent’s main economic engines.
And now, driven by a multitude of factors spanning electricity shortages, the pressure to move to sustainable operations, to simple economics, Africa’s mining sector is moving its energy-use profile away from fossil fuels.
According to the Economist Intelligence Unit (EIU) ‘load shedding and electricity shortages contributed to a 7% decline in South Africa’s mining sector in 2022.’ South Africa is home to the continent’s biggest mining sector.
And yet despite these and other headwinds the country’s mining sector’s sales were up, M+A activity showed signs of returning to pre-pandemic levels the sector is accelerating its moves to ensure independence and insulation from grid constraints, said the EIU.
A 2022 study by law firm Bird and Bird titled ‘Renewables for Mining in Africa’, said: “Africa’s power generation capacity is 80GW, of which 40GW is in South Africa and 23GW is allocated to mining projects, mainly in Sub-Saharan Africa. Thus, about 50% of the electricity production in Sub-Saharan Africa is generated by the mining sector. In addition, the cost of electricity generation in a mining project is between 10 and 35% of the project cost…Africa currently accounts for 15% of global mining expenditure, which remains low in relation to the continent’s resources. Mining is therefore set to expand in the coming years.”
Source renewables-for-mining-in-africa.pdf (twobirds.com)
Changing Investments
To power this expansion companies are investing in solar and wind renewables (where possible), using available local resources, and building renewable hybrid microgrids.
For example Anglo American Platinum is building a 100MW solar photovoltaic (PV) plant at its Mogalakwena mine in Limpopo Province, South Africa. The PV plant, which started construction in Q4 2022, is expected to be operational by the end of 2023 and forms part of Anglo American Platinum’s goal to achieve carbon neutrality across its operations by 2040.
Gold Fields, one of the world’s largest gold mining firms, is headquartered in Johannesburg. It’s stated energy strategy includes moves to ‘successfully start integrating renewable energy into our energy supply mix. We are currently operating largescale renewable energy plants at four of our eight mines. All our mines are evaluating renewables plants…’
The Group obtained 14% of its electricity from renewable sources in 2022. This includes hydroelectricity used by Cerro Corona*, which was certified as 100% renewable during 2022. It said: ‘Based on our current estimates, we expect this to increase to 22% by 2025, with renewable microgrids anticipated to come on-stream at St Ives* and Salares Norte*, and additional renewable capacity set to be added to the existing microgrids at Granny Smith*, Agnew*, Gruyere* and South Deep* by then.’ (* gold mines)
Since it launched its Energy and Carbon Management Strategy in 2017, Gold Fields has realised cumulative energy savings of 5.46PJ, resulting in cumulative cost savings of approximately US$231m.
At the smaller end of the sector Sub-Saharan Africa is home to one of the largest numbers of artisanal and small-scale miners in the world, close to an estimated 10 million, with at least a further 60 million reliant on the sector.
Microgrid Power Infrastructure for Mining
One of the most important attributes of mining is continuous operation – a serious power outage could cost a large mine $100m.
Bird and Bird’s report states: “In the mining sector, there is a permanent risk of energy blackouts. Indeed, mining industries have an increased dependency on energy. A temporary or more longer term loss of power would have strong financial implications”
It says renewable energy infrastructures, such as mini-grids, are now being considered as an answer to all this. These will be ‘integrated energy systems consisting of a group interconnected Distribution Energy Resources (like Production sources, PV, Genset, along with energy Storage to control some Controllable Loads) with clearly defined electrical Boundaries.’
In any such deployment therefore any transition of the energy supply must include the capacity to switch between intermittent renewables – even with large scale storage – to engine-based power generation.
Power Solutions, a division of Langley Holdings comprised of Bergen Engines (Norway), Marelli Motori (Italy) and Piller Power Systems (Germany) can fulfil these requirements through the features of the integrated use of Bergen Engines, Marelli Motori alternators and Piller Integrated Power Conditioning and Stabilisation (IPCS) and energy storage solutions.
Where a mine is primarily running on renewables Piller’s IPCS helps maintain power quality. When the system switches between the renewable energy source to the engine for baseload power the systems form a high-quality local network to supply the critical loads with uninterrupted power at constant voltage and frequency. The solution fulfils the entire energy requirements of the site.
Another advantage is that by utilising the electrical power and heat of Bergen’s 10MW+ modules (which can scale in units to tens and hundreds of MWs) through combined heat and power (C.H.P.) to simultaneously generate electricity and use the resulting waste heat, the efficiency of the gas engines system is 85% compared to 35% without waste heat utilization.
Local Microgrids – The Future
Across Africa the power industry is leapfrogging to renewable microgrids in favour of the long transmission distances, instability and power losses associated with traditional macro grids.
Power shortages in Southern and Eastern Africa are well documented. Of Africa’s 1.2bn population, roughly half, around 600 million people don’t have a dependable networked electricity supply. In sub-Saharan Africa two thirds of people have no regular access to electricity. https://www.usaid.gov/powerafrica/beyondthegrid]
As access to power grows through local renewables and community microgrids for more of the population, so large users such as the mining sector are investing in renewable local power accessed through microgrids to ensure their energy security and continue the journey to sustainable power use.
Just as the power companies in Africa are leapfrogging into building community, rural, and networked microgrids so mining companies are building 300MW-500MW industrial microgrids to ensure continuous operation.
The indications for the next decade are clear. For mining, along with other growing sectors of Africa’s economies, (such as digital and mobile) the role for Microgrid infrastructure in the form of sustainably fuelled engines, alternators, energy storage and microgrid management and stabilisation systems looks set to grow across every territory.
