Contrary to popular belief, a power solution incorporating renewable-energy solutions and diesel generators does exist and has been developed particularly for the mining industry, especially miners operating in regions with high average solar-peak yields, says renewable-energy solutions company Green Habitat CEO Maurits Perold.
The hybrid solution from Green Habitat is a solar photovoltaic (PV) and diesel-generator system suitable for Africa, owing to the continent having long, hot and sunny days, with minimal cloud cover.
Marketing for the hybrid solution is specifically aimed at mining clients requiring reliable, low-cost electricity that they can easily scale up or down.
Perold states that easy-to-install solar PV solutions are much more robust than other renewable-energy solutions, such as hydro-electric power plants or wind turbines, and are, therefore, “designed for the African continent”.
Further, solar PV is ideal for mining, as such operations often include vast tracts of land that are not always used and where extensive solar farms can be installed.
Green Habitat can design and install any size solar PV plant and has existing industrial installations of several megawatts throughout South Africa. “The only limitations are land space or rooftop space upon which to install solar PV panels,” Perold notes.
The Fuel Saver solution, also available from Green Habitat, was developed by Germany-based solar power company SMA Solar Technology. It uses PV panels that feed electricity into a central distribution system, which is also fed electricity generated by high-capacity diesel generators.
The solar PV component is the primary source of electricity during the day, with the diesel generators being the secondary source to supplement power demand.
However, at night or during periods of low solar yield – when the solar PV system does not produce electricity or low levels thereof – the diesel generators are increasingly used as the primary source of electricity. Therefore, the generators are required to be of sufficient size and capacity to support a mine’s night-time operations.
The mining sector in Africa currently depends significantly on diesel generators for electricity supply as most mines are located in remote areas and lack the transmission infrastructure from local grids.
As such, using this hybrid system significantly reduces a mine’s diesel consumption during the day, when production peaks at most mines.
The system also enables diesel generators to operate lower loads, thereby reducing their maintenance requirements, as their engines operate at lower revolutions a minute and for fewer hours.
Further, because the solar PV system provides primary power during the day, diesel generators can be taken offline at this period for maintenance and repair. As such, the generator’s sustainability is ensured, increasing its uptime and reliability.
The most significant challenges to gaining access to electricity in Africa are the lack of infrastructure or undercapacity issues, as many local power utilities in Africa operate on strained power grids, with insufficient capacity to supply miners or other large consumers with electricity.
“Miners are tremendously large consumers of electricity, so many of them have their own generators, which are continuously operated,” Perold says.
The Fuel Saver solution reduces the load on generators and allows generators to be run at more fuel efficient levels.
He notes that the average running cost of a large diesel generator is R3.50/kWh. “Using the Fuel Saver system allows for cost cutting of up to 60% of the generator’s running cost,” Perold says, adding that generators using the Fuel Saver system can be operated at as low as R1.40/kWh.
The solution can be incorporated into existing generator systems (or brownfield power projects) or installed as new power plants (or greenfield power projects).
Although he says fuel savings at brownfield power projects will be “significant”, Perold tells Mining Weekly that far greater savings can be achieved at greenfield power projects because the client can buy significantly smaller or fewer generators than previously required to meet its power demands.
In terms of capital costs, the return on investment for a solar PV-only installation is about ten years; however, this period is reduced to about five years when using the Fuel Saver model.
“The average solar PV panel has a life span of about 25 years,” he says, adding that solar PV solutions are long-term investments.