Although the development of micro- grid hybrid power solutions in South African mines is still in its infancy, multidisciplinary engineering consulting firm WSP Africa director Dinesh Buldoo says there is growing interest from mining companies to offset the risks to their business that power supply challenges can pose.
This can be done by conducting investigations on standalone or microgrid hybrid power generation solutions that may include a combination of alternative resources. These resources could be gas, diesel generators or renewables like solar and wind.
“There are different business models that are being explored and used globally – with different degrees of success – that can be successfully implemented in an African context. These include the self-generating, self-generating and powering communities, net metering and industrial pool models.”
The self-generating model entails a mine funding, building and operating a renewable power plant on site. A self-generating and powering communities model entails the local community near the mine obtaining support either from government or the mining company to construct a transmission line, while the net metering model is based on the mine selling any excess capacity generated by the renewables plant into the local grid. The industrial pool model entails a group of industrial companies entering a long-term power purchase agreement (PPA) and collectively funding, building and operating a shared power plant.
Should mining companies employ these models, mines can address risk associated with grid power interruptions or where grid power access is not available – as is often the case at mine sites that are remotely located from major urban areas, Buldoo mentions.
Also, mines can offset the unstable costs and risks associated with their reliance on and access to diesel, and make a positive contribution to carbon mitigation, in line with addressing climate risks.
Moreover, Buldoo highlights that using renewable-energy resources can be deployed using a renewable power plant that can be deployed close to the source of demand through microgeneration.
Using renewable energy is more cost- effective, as “in some instances, it is becoming cheaper to produce in cost-per-kilowatt power than fossil fuel, diesel or gas”, he points out.
“Using renewable-energy sources also means that the fuel is cleaner, as solar or wind energy have less environmental pollution impact, compared with technologies that rely on combustion of fossil fuels,” he explains.
Further, renewable energy allows for sustainability, as it uses natural resources, such as the sun and wind, which ensures that energy is produced consistently and can be harnessed to send power across the grid.
Buldoo concludes that renewable energy being deployed close to the source of demand will ensure power supply at a locked-in price for mines over the long term.