Modern Mining June 2020

photovoltaic (PV) technology is another source with huge potential to supply high energy needs. Mines can even have dedicated windfarms on some of their sites if wind resources are available.” On the consumption side of the equation, mines have to run compressors and pumps, for instance, but the question should not only be how to power these loads, but also how to do so economically. He says the solution is often as basic as using energy-efficient motors on pumps and compressors, installing high-efficiency compressors, retrofitting old compressors with tighter air gaps for greater effi- ciency, and using variable-speed drives (VSDs) and ventilation on demand (VOD). “Industry 4.0 is enabling us to integrate these solutions. For instance, where a series of pumps is installed to maintain a certain flow, the pumps do not need to run at full power and torque at all times; they can be controlled based on the flow to adjust the amount of energy used by each pump.” This functionality, says Vargas, is already avail- able. WEG drives, for example, feature Pump Genius, which optimises efficiency while minimising power usage on multiple pumps simultaneously. “It’s not only about the ability to generate elec- tricity on a large scale, but also about its large-scale usage. A 10% saving on energy consumption is not only a reduction in the electricity bill; it is a reduction in required energy generation capacity too, leading to capex and maintenance savings.” Vargas says mines are the perfect environment to achieve the optimisation of both demand and consumption. “For instance, some of our customers are devel- oping more efficient fans which can generate more air-flow for less energy. Instead of 10 fans, you may now only need five. Instead of running them all at full power, adjust the air flow according to the require- ments of the application.”

economy going forward, but calls for a move away from the rationale that energy-intensive applications need large generation plants to meet demand. “We must look at technological advancement as an opportunity to tackle both sides of the energy equation in mining: power supply and power con- sumption. In terms of the latter, we must explore the available technologies to establish more efficient and sustainable energy sources, at reduced cost.” He says there is a more cost-effective and envi- ronmentally friendly source of energy to consider, in the form of natural gas. “We can also look to solar generation, which is becoming available on a large, industrial scale. Solar

Above: Zest WEG engineered substation solutions can integrate energy generated from power sources with the electrical network. Left: Zest WEG can respond rapidly to the mining industry’s evolving energy mix, with products such as WEG’s centralised inverter stations.

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