Courtesy of Christian Stiebahl
B2Gold Corp. is building a $38 million hybrid solar/heavy fuel oil plant at its Fekola mine in Mali, and expecting to save $9 million in energy costs per year.
Banking on the sun Although construction on B2Gold’s solar plant in Mali is currently on hold, the company is committed to the alternative energy source By Lynn Greiner
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uilding on the success of the solar project at its Otjikoto mine in Namibia, B2Gold’s Fekola mine in Mali will eventually be home to one of the largest off-grid hybrid solar/heavy fuel oil (HFO) plants in the world. Originally slated for completion in the third quarter of this year, construction has been temporarily suspended due to issues related to COVID-19 (it is expected to be finished within six months of restarting). When commissioned, the plant will provide 30 megawatts of power in addition to the existing 64 megawatt HFO and diesel capacity. The solar plant will also have a 15.4 megawatt hour battery component with up to 17.3 megawatts of discharge power.
Why solar? B2Gold originally began processing ore at Fekola in September 2017, but within a year the company wanted to expand its operations and increase its throughput from six million tonnes per annum to 7.5 million. Eight CAT 16CM32 HFO generators and four CAT 3516B diesel generators (totalling an installed capacity of approximately 64MW) powered the plant, but the expansion provided an opportunity for B2Gold to reduce some operating costs while reducing the company’s carbon footprint. An additional source of power wasn’t strictly needed – after the expansion is completed, the power demand will be 40 megawatts, an amount the existing HFO plant can meet – but adding in another energy source makes more engines available for maintenance. “At the time we were making [the original] construction decision for Fekola, we looked at a number of sources of energy,” 36 | CIM Magazine | Vol. 15, No. 3
said Dennis Stansbury, senior vice-president of engineering and project evaluations at Vancouver-based B2Gold. “We’re a long way from the grid in Mali, and the amount of power available on the grid was in question, so we had to do something standalone and made the decision to construct the HFO plant. “When we later looked at upgrading the power plant, we looked at wind generation, but there are insufficient sustained winds, and the combination of a flat countryside and a river that dries up for part of the year meant that hydro power was out. That left solar as the best option to combine with our existing power plant. “When we ran the numbers with all the current information, it has about a four-year payback,” Stansbury said. “And so my question… wasn’t, ‘well, why did you do solar?’ It was ‘why would you not do solar?’ It’s has a very short payback and that’s why we went so big and chose a 30 megawatt plant.”
Reasons for the switch Money, for starters. Based on our study assumptions, total estimated cost savings will be about $9 million per year; the mine’s life has now been extended to 2030, with B2Gold expecting “significant estimated increases in average annual gold production to over 550,000 ounces per year during the five-year period 2020–2024 and over 400,000 ounces per year over the life of mine” working on the estimate of 81 per cent indicated and 19 per cent inferred mineral resources. The solar plant, with a capital cost of $38 million, will reduce processing costs by more than seven per cent, and save at least
