Modern Mining June 2019

POWER SUPPLY AND ENERGY EFFICIENCY

Vice President – Global Head of Business Development at Total Eren, said: “This proj- ect demonstrates the benefits of integrating renewable energy in the mining industry. We are looking to replicate this type of hybridisa- tion, especially in Africa where mines cannot always rely on the national grid. Renewable energy coupled with either storage or thermal- based power generation represents a truly viable option for industrial consumers since it enables for competitive, reliable and clean power supply.” The second major solar project to be com- pleted last year was a 7 MW solar ‘farm’ or plant at B2Gold’s Otjikoto gold mine in Namibia. One of only two gold mines in the country (and by far the bigger), Otjikoto produced approxi- mately 167 000 ounces in 2018. Otjikoto is what is known as an ‘island energy producer’ – meaning that it is off the Namibian national grid. Although not in a par- ticularly remote area, the decision was taken during the development phase of the mine to install an on-site thermal power station when it became evident that relying on a grid con- nection would have delayed the start-up of operations. The thermal plant has a generat- ing capacity of 23,5 MW provided primarily by four Cat medium-speed HFO generators. The solar plant complements the con- ventional generating capacity on site at Otjikoto with the integration being managed by Caterpillar’s Microgrid Master Controller (MMC). The MMC not only regulates the energy being fed to the HFO plant but allows for the seamless selection of the mine’s two energy sources (HFO or solar), choosing the

million in fuel costs) and avoid 274 110 tonnes of CO 2 emissions. One of the motivations for the project was the fact Essakane’s transition to processing harder ore resulted in energy consumption at the mine increasing from about 14 GWh/month in 2013 to 26 GWh/month in 2015. Commenting on the installation at the time of the launch, Fabienne Demol, Executive

The Otjikoto solar ‘farm’ comprises 62 400 thin- film solar panels (photo: B2Gold).

“This project demonstrates the benefits of integrating renewable energy in the mining industry."

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June 2019  MODERN MINING  45