Gold producer B2Gold Namibia on Wednesday celebrated the opening of the B2Gold Otjikoto solar farm, in the Otjozondjupa region.
The event was officiated by Namibian Mines and Energy Minister Tom Alweendo. He stated that the Otjikoto solar farm is “yet another significant contribution in the private sector’s drive for sustainable energy solutions”.
The opening follows B2Gold breaking ground on the construction of a 7 MW photovoltaic (PV) solar power plant at its Otjikoto mine, in 2017.
“This solar plant will deliver positive economic, environmental and social impacts that are likely to outlive the life-of-mine.
“This solar plant is also one of the largest installations of its kind in Namibia, serving as a sustainable power solution as B2Gold works to improve economic returns, reduce impacts on the environment, and could potentially be a funding source for community development,” Alweendo said.
Prior to the inclusion of the solar plant in the mine’s energy portfolio, the Otjikoto mine obtained 100% of its energy requirements from 24 MW of installed generation capacity at the Otjikoto power plant, comprising of heavy fuel oil (HFO) diesel generators.
With a consistent demand of 12.5 MW all day, the plant consumed 21.7-million litres of HFO during 2017, costing about $10.5-million.
At the opening of the plant, B2Gold Namibia projects and compliance manager John Roos outlined the reasoning for the facility’s development, which included B2Gold’s commitment to environmental stewardship, its dependence on a steady supply of HFO, which also exposed it to increasing oil prices, and the company’s focus to remain a low-cost producer.
“Driven by these challenges, the B2Gold project team embarked on a detailed financial feasibility study early in 2016 to prove the financial viability of adding a 7 MW solar plant to Otjikoto’s energy portfolio. Based on the results of this study, the project was approved in October 2016, with an estimated project cost of $8.5-million,” explained Roos.
The project team evaluated a number of potential vendors within a competitive solar industry in Namibia. Industrial manufacturer Caterpillar’s CAT Microgrid Solutions, through its local dealer Barloworld Power South Africa, was chosen for the construction of the solar plant.
The decision was principally based on the technical capabilities of the CAT Master Microgrid Controller (MMC), which has been designed specifically to seamlessly integrate solar PV energy with Otjikoto’s HFO and high-speed engines.
This indicates the MMC having the capability to automatically select the cheapest form of energy (from the multiple sources of energy available) with no human intervention.
The solar PV array comprises about 62 400 115 W CAT thin-film solar panels manufactured by First Solar.
These panels are mounted on a PiA solar tracking system. Direct current power is converted to alternating current power through 240 Sunny tri-power three-phase SMA string inverters.
Energy generated by the solar plant is evacuated to the Otjikoto power plant by a 3.5 km powerline.
The CAT MMC, which is installed at the Otjikoto power plant, controls the flow of energy from the solar to the power plant.
The feasibility studies indicated expected savings of 20% of HFO consumption through the reduction of load to the power plant, as well as savings on maintenance costs on the power plant’s HFO engines.
B2Gold expects it will reduce energy costs by 14% for this year.
The plant will allow the company to significantly reduce fuel consumption and greenhouse-gas emissions from the site’s current 24 MW HFO power plant.
B2Gold is considering the use of the solar plant as an income-generating asset after the mine closes, owing to depletion of its reserves. Funds generated by this asset could be used to support ongoing corporate social responsibility activities in the region long after the mine has shut down.