The new landmark 7 MW solar farm at B2Gold’s Otjikoto gold mine in Namibia – which became operational in March this year – has been officially inaugurated by the country’s Minister of Mines & Energy, Tom Alweendo. The event, held on 29 May, was attended by around 120 guests, including Modern Mining’s Editor, Arthur Tassell.
An aerial view of the Otjikoto solar farm (photo: B2Gold).
The solar farm will reduce dependence on the existing 24 MW heavy fuel oil (HFO) power plant at the mine (which is not connected to the Namibian grid), allowing considerable fuel savings and reducing the mine’s carbon footprint. It is expected to reduce Otjikoto’s energy costs by 14 % in 2018.
The decision to build the solar farm was taken after B2Gold embarked upon a detailed financial feasibility study in early 2016. Based on its positive results, the project was approved in October 2016.
The facility – which can be easily expanded due to its modular design – utilises Cat Microgrid Solutions technology and was provided by Caterpillar in partnership with its local dealer Barloworld Power in terms of an EPC contract signed in mid-2017.
Pictured at the inauguration of the Otjikoto solar farm are (from left): Bill Lytle, Senior VP Operations of B2Gold; Dr Leake Hangala, Chairman of B2Gold Namibia; Tom Alweendo, Namibia’s Minister of Mines & Energy; Mark Dawe, Country Manager and MD, B2Gold Namibia; and John Roos, Manager Projects & Compliance, B2Gold Namibia (photo: Arthur Tassell).
A major consideration in selecting the Caterpillar technology was the state-of-the-art technical capabilities of the Cat Master Microgrid Controller (MMC). It has the ability to seamlessly integrate solar PV energy with Otjikoto’s HFO and high-speed engines. Furthermore, it can automatically select the cheapest form of energy (from the multiple sources of energy available) with no human intervention.
The solar PV array comprises approximately 62 400 Cat thin film solar panels, manufactured by First Solar. These panels are mounted on a PiA solar tracking system. DC power is converted to AC power through 240 Sunny tri-power three-phase SMA string inverters. Energy generated by the solar plant is transmitted to the Otjikoto power plant via a 3,5 km powerline.
As a novel initiative, B2Gold is considering the utilisation of the solar plant as an income-generating asset after the mine closes due to depletion of its reserves. Funds generated by this asset could be used to support ongoing CSR activities in the region long after the mine has shut down.
An open-pit operation, Otjikoto is located in the Otjozondjupa Region of Namibia, approximately 300 km north of Windhoek. Officially opened in mid-2015 (although it achieved its first gold pour in late 2014), it has been one the most successful gold mine start-ups seen in Africa in recent years. In 2017 it produced a record 191 530 ounces at a very low cash operating cost of US$468/oz.