More than 30 land-based wind farms have been built along the windy Cape coastline and in other parts of the country, but there are no such power farms in the sea off South Africa.
If the proposed Gagasi Offshore Floating Wind Farm goes ahead, the new installation could cover an area of 140km2 and include up to 54 gigantic turbines (with the tips of the turbine blades spinning at 270m above sea level, or possibly 370m).
To put that height into perspective, the tops of the blades would be more than three times higher than Durban’s Southern Sun Maharani hotel (118m) and also higher than the 55-storey Leonardo hotel in Sandton, Johannesburg (228m).
According to a background information document published as part of the compulsory environmental impact assessment (EIA) process, the Gagasi farm would be located in deep waters off the coast of northern KwaZulu-Natal, slightly north of the heavy industry and harbour city of Richards Bay.
Up to 54 “floating” turbines would be tethered to the sea bed in a long rectangular block which is about 5km from the coastline at its closest point in the north, and 17km off the coast at its closest point in the south. Due to the size and height of the turbines, the installation would still be visible from the shoreline.
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More than 30 land-based wind farms have been built along the windy Cape coastline and in other parts of the country, but there are no such power farms in the sea off South Africa.
If the proposed Gagasi Offshore Floating Wind Farm goes ahead, the new installation could cover an area of 140km2 and include up to 54 gigantic turbines (with the tips of the turbine blades spinning at 270m above sea level, or possibly 370m).
To put that height into perspective, the tops of the blades would be more than three times higher than Durban’s Southern Sun Maharani hotel (118m) and also higher than the 55-storey Leonardo hotel in Sandton, Johannesburg (228m).
According to a background information document published as part of the compulsory environmental impact assessment (EIA) process, the Gagasi farm would be located in deep waters off the coast of northern KwaZulu-Natal, slightly north of the heavy industry and harbour city of Richards Bay.
Up to 54 “floating” turbines would be tethered to the sea bed in a long rectangular block which is about 5km from the coastline at its closest point in the north, and 17km off the coast at its closest point in the south. Due to the size and height of the turbines, the installation would still be visible from the shoreline.
The proposed Gagasi wind farm off the coast of Richards Bay in KwaZulu-Natal. (Graphic: Jocelyn Adamson)
While Gagasi could lead to a sizeable reduction in carbon emissions from Eskom’s coal and other fossil fuel emissions, the potential environmental impacts of mega-scale clean energy projects are far from being resolved.
The proposed wind farm is a collaboration between the Greek-Swedish cleantech group Hexicon AB and the South African-based Genesis Eco-energy Developments group.
Genesis was established more than 20 years ago by renewable energy entrepreneur David Chown, who entered into several business partnerships to build some of the country’s first wind and solar farms – including those at Jeffreys Bay, De Aar, Droogfontein, Loeriesfontein, Khobab and Noupoort.
According to his LinkedIn profile, Chown helped to set up the Pretoria branch of the Earthlife Africa environmental group in his student days and was active in several campaigns on clean energy, toxic waste, climate change and genetically modified organisms.
However, turning these latest plans for offshore wind into reality is likely to prove challenging for several reasons, including the high cost of such installations, securing environmental approvals and government lease agreements.
China, Germany, Taiwan, the Netherlands and the United Kingdom are among the leaders in the offshore wind power arena.
Wind power (on land and sea) now accounts for roughly 28% of Germany's utility-scale electricity generation, exceeding coal (19.5%) and solar (17.5%). Germany already has nearly 30,000 wind turbines and plans to build up to five new wind turbines daily over the coming decades.
China is also planning the world’s largest offshore wind farm, the 43GW Chaozhou project that aims to provide enough electricity to power more than 13 million homes.
‘Ideal location’
On paper, the sea off South Africa has been rated as an ideal location for offshore wind power.
A recent study by Stellenbosch University mechanical engineering researchers Gordon Rae and Gareth Erfort suggests that offshore wind farms could theoretically supply between 15% and 800% of South Africa’s current annual electricity demand depending on whether they are located in shallow or deep water.
The SA Wind Energy Association (SAWEA) says there are now 34 (land-based) wind farms across the country, with a total output of 3,442MW, but notes that “more progress is needed in developing offshore wind energy”.
SAWEA suggests that developing wind farms at sea requires the government to take a leading role in developing a clear policy framework. Though costs were dropping steadily, the cost of floating offshore wind farms remained significantly higher than land-based wind power.
SAWEA also suggests that the biggest uncertainties in this area relate to the ownership and permitting process for new offshore wind farms.
Because the sea falls under government ownership it was likely that offshore wind developers would need to secure permits from the Department of Forestry, Fisheries and the Environment, the SA Defence Force and other departments.
An offshore wind turbine installation off the coast of Taiwan. (Photo: An Rong Xu / Bloomberg via Getty Images)
Earlier in October, the Acer Africa environmental consultancy group published a 15-page public information document and invited interested parties to participate in the mandatory environmental authorisation process.
Acer states that construction is likely to be phased over 10 years and that the EIA process would consider the worst-case scenario in terms of the maximum size of wind turbines expected to be available at the proposed time of construction.
To convert the power generated by the wind farm into the Eskom grid, the project could require a new substation at Richards Bay, along with up to four bottom-fixed substations, or up to five floating substations, or up to 10 subsea mounted substations.
Acer suggests that floating foundations would allow the proposed wind farm to be located further from shore in deep waters, “thus limiting impacts on coastal seabirds and terrestrial wildlife”.
A preliminary list of the potential environmental impacts associated with the Richards Bay project included the effect on marine seabed environments; laying of the cables and anchoring floating platforms in sensitive marine environments off the KZN coast.
The offshore wind farm also had the potential to disrupt marine ecology (birds, marine mammals, turtles, etc.), and commercial and recreational fisheries during installation and operation.
According to the Fisheries division of the US National Oceanic and Atmospheric Administration (NOAA), offshore wind energy projects could:
- Increase ocean noise, which could affect the behaviours of fish, whales, and other species;
- introduce electromagnetic fields that affect navigation, predator detection, communication, and the ability for fish and shellfish to find mates;
- create a “reef effect” where marine life cluster around the hard surfaces of wind farms; and
- increase vessel traffic, which could lead to more vessel strikes.
Several bird species are also vulnerable to collisions with rotating turbine blades.
Further information on the project is available on the Acer Africa website or from consultant Giles Churchill: E-mail: gagasi@acerafrica.co.za DM
https://www.youtube.com/watch?v=REeWvTRUpMk