The Oelsner Group, the company that built South Africa’s first, and as yet only, commercial wind farm near the West Coast town of Darling, is planning an ambitious 750 megawatt offshore wave energy project in the same area.
The amount of electric energy that can potentially be derived from the waves that continuously pound our planet’s oceans is enormous and has been estimated at as much as 2,700 gigawatts. But for a number of reasons, wave power is lagging far behind solar and wind as a source of green, renewable energy. If companies like the Oelsner Group have their way, this situation will change in the not-too-distant future.
Technologies of various design have been developed to capture the energy contained in the rise and fall of ocean waves and converting it into electricity. Currently, the majority of the existing wave power installations around the globe are experimental or demonstration plants.
Experiments around the world
The world’s first experimental wave farm was opened in 2008 in Portugal, but it was closed down for financial reasons only two months later. Today, an experimental wave farm is in operation off the coast of Western Australia. In Scotland, the first phase of a wave power plant was launched in May last year and a so-called wave hub, with an eventual capacity of 20 to 40 megawatts, is proposed for the north coast of Cornwall in England.
The coast of South Africa, especially its West Coast, has been identified as an area of great wave power potential. The highly energetic wave regime of the region is largely related to its proximity to a major storm-generation zone in the South Atlantic. Professor Deon Retief, a respected local marine engineer, believes that, at a “very conservative” estimate, some 8,000 to 10,000 megawatts of electricity could be generated along the west and south coasts of the country’s Western Cape Province. Tapping this huge amount of energy could help South Africa reduce its almost exclusive dependence on climate changing coal-fired power stations.
Energy that never stops
One of the main advantages of wave power over solar and wind energy is that waves keep going 24/7 and although they vary in intensity depending on weather and season, wave conditions tend to be much more predictable than the sun and wind. There are some potentially negative impacts as well, of course. These include possible noise and visual pollution and as yet largely unknown impacts on water flow, sedimentation and marine flora and fauna.
The Oelsner Group’s proposed South African wave energy project is based on a home-grown design developed at the University of Stellenbosch, known as the Stellenbosch Wave Energy Converter (Swec). It consists of partially submerged v-shaped collector arms with a capacity of 5 megawatts each. On completion, the wave farm would include 150 such units, installed about 1.5 kilometres from the shore in a line stretching for a distance of some 40 kilometres parallel to the coast.
Huge issues to resolve
A number of hurdles still need to be overcome before the project becomes a reality. Some consider the technology still too immature and comparatively expensive for commercial deployment. At the very least, South African government regulations, which do not make any provisions for wave power at the moment, need to be negotiated, environmental impact assessments need to be carried out and, above all, funding needs to be secured. An initial demonstration plant is expected to cost about R100 million ($14 million) and the project as a whole is estimated to require around R15 billion (more than $2 billion) in total.
Realistically then, it looks as though it will still take some time for South Africa’s first wave power station to come online. Better late than never, I guess. Despite the South African government’s supposed commitment to renewable energy, its actual implementation in the country – blessed as it is with extraordinary solar and wind resources – has been painfully slow. So any progress (even a promise of progress) in the development of local green, clean energy has to be welcomed.
Andreas is a book shop manager and freelance writer in Cape Town, South Africa. Follow him on Twitter: @Andreas_Spath
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