By Selma Shiwaya
As Namibia continues to harness the abundant renewable energy resources, the country’s national power utility NamPower has considered an investment of N$1.9 Billion into a 40 Megawatts biomass project. The Otjikoto Biomass Power Station forms part of the generation projects of NamPower targeted to generate a total of 100 Megawatts.
According to Grant Muller, head of generation projects at NamPower the project supports renewable commitments under the energy and renewable energy policies. These policies aim that Namibia becomes energy secured as well as a net exporter by 2030 by leveraging renewable resources. In addition, the policies aim that 70 percent or more electricity installed capacity in Namibia should be from renewable sources by 2030. The project also support the 5th pillar of the National Development Plan which aims to increase local generation capacity to 755 Megawatts by 2021 or 2022 thereby increasing the national electrification rate to 50 percent by 2021.
The project has a conservative harvesting yield assumption of 12.65 tons per hectare. “We are expecting to conservatively extract at least 40 million tons of encroacher bush biomass wood chips from a 100 kilometer radius from the site area of plus minus 44 hectares. On an annual basis the power station will use around 200 000 tons of biomass wood chips.” said Muller.
Muller further explained that power would be generated from a single steam turbine with either one 40 megawatts boiler or two 20 megawatts boilers. “The power station will be using grate fired boiler technology as it allows burning of a bigger woodchips size,” he said.
The lifetime of the Otjikoto Biomass Project is expected to be 25 years however the project can be sustained for plus minus 200 years’ operating at a 70 percent capacity factor and without considering any regrowth of the biomass resource.
Taking sustainability of other natural resources in consideration, Muller assured that the power plant is going to be water friendly as possible. “The process will be ending with condensing of steam by using an air cooler. Moreover, the steam cycle is going to be a completely closed cycle to ensure the minimized usage of water,” he explained. The consumption of water is expected to be between five and seven cubic per hour.
The Otjikoto Biomass Power Station will ensure security of supply and promote the biomass chain in Namibia. Muller says that while the project may provide a concept for future similar projects it will also increase the livestock carrying capacity and restoration, ground water potential and reduce greenhouse emissions.
The project is expected to be completed by 2023 and Nampower will be operating the power station while the Electrical Board of Namibia will be regulating the generation.