As South Africa’s industry bears the brunt of devastating power cuts, Zest WEG, the South African subsidiary of Brazilian motor and controls manufacturer WEG, is encouraging mining companies to start adopting integrated, holistic solutions that will reduce energy consumption while diversifying their own energy mix.
Increasingly, it is becoming essential that, in mining operations, the energy source is developed and optimised in conjunction with the equipment being selected to support and run mines’ operations, says Zest WEG integrated solutions executive Alastair Gerrard.
South Africa has been hard hit by rotational load-shedding, placing severe pressure on the mining industry, which accounts for about 48% of the country’s energy intensive users.
In December, power utility Eskom took an unprecedented step of moving the country to stage six rolling blackouts, resulting in some of South Africa’s largest platinum and gold mining companies suspending some operations.
The overall impact of load-shedding on South Africa’s economy is believed to run into billions of rands, with a Council for Scientific and Industrial Research report revealing that 1 353 GWh, or 530 hours, of rotational cuts had been implemented in 2019, resulting in an economic cost of between R60-billion and R120-billion.
Further, the uncertainty associated with an unreliable and intermittent energy supply has a significant impact on the feasibility of a mining project, as additional capital expenditure would need to be set aside to develop and construct energy sources sufficient to support the operation – over and above the capital costs required to develop the mine and its associated processing facilities, says Gerrard.
In line with this, mining companies are intensifying their focus and striving toward determining new and innovative ways to become more operationally efficient and, as a result, reduce operational expenditure.
In their drive for operational sustainability, mining operations should no longer focus solely on the source of energy and its procurement in the most cost-effective way, but also how energy can be more efficiently used in the long term, Gerrard tells Mining Weekly.
“By saving on operational expenditure through the reduction in energy consumption and leveraging technology, the return on investment for mining companies can be greatly improved through the significant savings that can be achieved,” he says.
Engaging mining companies at an early stage of a project’s development will ensure the successful integration of a holistic, cost-effective and reliable solution – from renewable energy through to energy efficient electric motors, besides others – to overcome challenges such as insufficient and unreliable supply.
For example, by using premium efficiency (IE3) motors, as opposed to standard efficiency (IE1) motors, an increase in energy efficiency of between 5% and 30%, depending on the range, can be achieved.
A critical aspect of a mining operation, electric motors account for 55% to 60% of the sector’s energy consumption.
Further, the adoption of a minimum efficiency performance standard (MEPS) for electric motors can potentially be a low-hanging fruit to significantly reduce the strain on the country’s national electricity grid.
The application of a MEPS for electric motors will result in the phasing out of the least efficient electric motor classes by setting a minimum standard for the effi- ciency of motors imported and sold in South Africa.
Gerrard also points out that Africa has an abundance of natural resources that can be used as the fuel to produce energy and the potential is there to build power generation plants or facilities.
These include hydropower, renewable energy, coal and biomass, in addition to several different fuel sources, that can be used to develop power sources.
“We see a growing trend within the African mining industry to incorporate renewable energy solutions as part of their requirement to achieve reliable, secure and cost-effective energy, especially in cases where grid supply is not always available.”
In South Africa, Gerrard notes, some mining companies are at a well advanced stage in the development of solar photovoltaic (PV) plant projects as an additional means to reduce their dependency on the national grid.
The cost of energy from the grid is expected to continuously rise over the coming years, whereas the cost of renewable energy technologies has and will continue to decrease.
In line with this, Zest WEG has made the strategic decision to enter into the renewable energy market. Its parent company in Brazil, WEG, has been successful in securing many projects in the renewable-energy sector, both solar PV and wind projects.
This means that Zest WEG is able to offer a power generation solution or an electrical infrastructure solution, as well as the overall integration of these solutions to meet client-specific requirements.