Most unusual job created by wind power

Wind power has created an interesting job for a team of ten people at the Excelsior wind farm near Swellendam: spotting approaching birds to stop fatal collisions with turbine blades.

The bird spotters act as an early warning system, giving technicians time to halt the turbines’ rotation. The bird protection programme is known as shutdown on demand.

Speaking to TimesLive, the team’s head, Clarissa Mars, says protecting the endangered black harrier is top of mind. Only around 1,300 of the raptors remain.

Spotters assess birds’ flight patterns, and if they anticipate one heading towards a turbine, they radio the control centre to stop the blades.

It takes just under a minute to halt the blades. Mars says the movement of some birds, like the Cape vulture, is easy to predict.

However, she noted that the smaller, faster black harrier is far more challenging.

“With the black harrier, the flight patterns always change, especially when it comes to breeding season,” she told TimesLive.

Their hunting techniques also present a danger. Once it has captured prey on the ground, it soars upwards as quickly as it can.

Mars added that they don’t care about their surroundings while doing this, putting them at risk of being hit by turbine blades.

Excelsior wind farm reached commercial operation in December 2020. Since then, the corpses of two black harriers killed by turbines have been found.

Located roughly 30km from Swellendam in the Western Cape, the wind farm was awarded under the fourth bid window of South Africa’s Renewable Energy Independent Power Producers Programme in 2015.

It reached financial close in 2018.

Excelsior features 13 Gold Wind permanent magnetic drive turbines, each generating up to 2.5MW. Its rated maximum output is 31.9MW.

The project spans an area of 2,300 hectares and has an annual output of roughly 132GWh.

Excelsior wind farm

According to the energy department’s IPP database, it is currently the 30th-largest operational onshore wind farm in South Africa.

South Africa currently has 18 onshore wind farms that each contribute at least 100MW of power to the grid.

The largest are Oyster Bay Wind Farm and Roggeveld Wind Farm, operated by Enel Green Energy and Red Rocket, respectively.

They each generate up to 140MW of power. Oyster Bay Wind Farm is located in the Kouga municipality in the Eastern Cape, while Roggeveld straddles the boundary between the Western Cape and Northern Cape provinces.

Adding further renewable energy projects to the grid in these provinces presents a challenge as the transmission grids in these areas are full or close to it.

According to Peter Attard-Montalto, Intellidex’s managing director for capital markets, they will remain full until at least 2027.

He also said Eskom was spending less than R1 billion of the R14.5 billion it needs to spend each year on upgrading the transmission grid.

Eskom has committed to expanding transmission grid capacity in the region. However, it is making slow progress.

Eskom completed just three of the five transmission line expansion projects it had planned for the 2023/24 financial year, achieving just 74.4km of the 166km expansion it had in its pipeline for the year.

Through its Transmission Development Plan, Eskom aims to build 14,000km of 132kV, 275kV, 400kV, and 765kV transmission lines in ten years.

The 74.4km it completed in 2023/24 represents just 5.3% of the 1,400km it will need to build each year to meet this deadline.

Until there is sufficient transmission grid capacity in the Cape provinces, it won’t be possible to distribute energy from new IPP projects to other parts of the country.