25 Degrees in Africa talked to William Gould, CEO of Tsebo Energy Solutions about how sustainable energy solutions can assist mines in maximising their bottom line.

According to Gould, roughly 30% of operating costs of mines goes into energy and particularly electrical energy. While many players recognise value in going the efficient route, implementation is often a challenge on its own.

“Mines are very conscious of their energy consumption and have for many years been trying to improve, but most interventions need capital investment and with many competing demands for capital, it often remains a non-core priority,” he says.

In order to make sure that these investments make a real difference, before embarking on any energy initiatives, Gould notes that it is imperative to consider the equation of supply and demand in the mining sector. From the demand side, mines need to look closely at all the individual energy consumption processes and determine what they could and should be doing to lower the amount of energy they require from the energy supply.“You don’t want to be operating an inefficient mine with sustainable resources,” he says. “That is a very expensive exercise.”

According to Gould common practices need to change to move forward and there are some very logical things that can be done, but South Africa lags global markets in some practices. For example, plants that are not maintained uses more energy and by just selecting a high efficiency (IE2) pump over a standard efficiency (IE1) version, mines can achieve large savings when taking into account the lifespan of the pump’s operation. In the ventilation of mines, a lot of efficiencies are already being realized  such as fans that consume 30% less energy than the ones traditionally used.

Once the energy demand is down to its lowest consumption level, it starts becoming sensible to consider renewable sources of energy supply, especially in areas with no existing power infrastructure from a supply authority. In the South African and African context, the high level of irradiance makes solar energy solutions an attractive option with a six to seven hour productive window a day, and in some areas wind is also an abundant natural resource.

“What we are seeing from a global point of view is that opting for photovoltaic solar systems is a very viable opportunity. To run diesel electric plants, it costs around 35 US cents per kilowatt hour, compared to about 10 US cents per kilowatt hour in parts of Southern Africa with developed infrastructure. With solar panels you can generate electricity at around 17 US cents per kilowatt hour,” Gould states.

However, because storing solar power is very expensive, Gould explains that it should predominantly be used as supplement during daylight hours. He suggests using as much as solar energy possible and at least matching the base load with renewable energy, but only when using energy efficient equipment.
Ultimately, for mines to make sensible investments into sustainable business practices that will benefit them in the long run, they need measure their power consumption, understand how they can reduce their consumption profile, and then select proven energy efficient technologies that include renewable sources.