‘collision course’ with wind farms
wind turbines in the Eastern Cape.
“This is an alarming situation for us, as these two birds were being tracked and we can only guess how many more vultures and other birds have fallen victim to these structures.”
It is working closely with environmental consultancy companies where new structures are going up “to advise as to best practice for the implementation of these wind farms”.
“However, with vultures ranging as widely as they do, it is extremely difficult to declare a wind farm far enough from vulture movement that it does not pose a threat.”
According to Webster, the Eastern Cape, home to the Cookhouse and Stormberg Renewable Energy Development Zones (REDZ) is “a collision course” for Cape vultures.
“Wind energy needs wind to be able to generate power, so they are built where the wind is ‘better’. We all know wind will always blow well on escarpments, however, Cape Vultures rely on wind thermals to allow them to fly as they are generally not agile flyers [with a] wingspan of six metres from tip to tip and need thermals to lift their bodies, so they use the escarpments to effectively do this.”
As they are not agile flyers, they cannot change direction or twist and turn as smaller birds can and are more exposed to colliding with the blades, which are turning at over 300km/h at the tip.
“The risk is huge as … they do not fly looking out for obstacles to avoid. They are searching for food and suitable perching areas.”
“When it comes to Cape vultures and wind energy, we can confidently say they are at a high risk of being struck by turbine blades,” said Samantha Ralston-paton, who is the birds and renewable energy project manager at Birdlife South Africa.
There are already a large number of wind farms with environmental approval “uncomfortably close” to vulture roosts and colonies.
“Some of those that are already operational are doing a good job at monitoring, mitigating and reporting on their impacts. Others are not.”
There are many alternative, less risky, places that have good wind resources.
“We should focus on developing those areas first. Hopefully by the time we need to look at developing high-risk sites, we will have secured 1) watertight commitments to monitoring and mitigating impacts during the operational phase; 2) mitigations that have been proved to be effective and affordable and 3) government resources for active oversight and enforcement at operational wind farms.”
The draft multi-species biodiversity management plan for vultures in South Africa cites the major threats to Cape vultures as unintentional poisoning, electrocution on or collision with energy infrastructure and intentional poisoning for African traditional medicine. It notes how the rapid development of wind energy in southern Africa represents an additional threat to already fragile populations of African vultures.
“The distribution of the vulnerable Cape vulture, in particular, overlaps considerably with wind energy development areas in South Africa, creating conflicts that can hinder both vulture conservation and sustainable energy development.”
Cape vultures are known to collide with turbines at wind energy facilities.
“Indeed, the last five years have shown concerning numbers of mortalities on wind farms, particularly in the Eastern Cape. There have been 24 Cape and three white-backed vulture fatalities at wind farms reported to date (this includes a few electrocutions).”
The current fatality rate of Cape vultures at South Africa’s wind energy facilities is 0.008 birds per turbine per year, but “these figures are not an accurate reflection of the actual number of vulture fatalities. “Not all wind farms are monitoring, reporting and/or mitigating fatalities,” the plan reads.
When REDZ are taken into account, a significant overlap exists between the Cape vulture range and operational and proposed wind energy facilities.
“Subsequently, there is pressing concern around the potential cumulative impact of wind energy facilities on the Cape vulture population within these areas of overlap,” the plan states.
This is compounded by the recent gazetting and fast-tracking of REDZ across the country, “which is sure to increase the level of collision risk for Cape vultures and other collisionprone species”.
Santosh Sookgrim, senior technical adviser for the South African Wind Energy Association, said it actively partners with Birdlife South Africa to discuss the roll-out of mitigation measures via the association membership.
“There are a number of mitigation measures being employed by the industry such as Shut Down on Demand protocols with active and observer-led activation measures,” he said.
“Curtailment is being explored during high migration periods. Several wind farms actively participate in conservation and breeding programmes.”
The challenges involve balancing the commercial aspects and profitability of the plant with the mitigation and conservation efforts, he said.
“Currently, one of the key challenges is the opposition to the expansion of the blade patterning programme by the South African Civil Aviation Authority.”
Peter Mbelengwa, spokesperson for the department of forestry, fisheries and the environment, said to fortify existing assessment and monitoring measures, it will soon be introducing the Cape vulture protocol, “which provides criteria for the specialist assessment and minimum report content requirements for determining impacts on Cape vultures associated with the development of onshore wind energy generation facilities, which require environmental authorisation”.
The assessment and reporting requirements of this protocol are associated with a collision risk potential identified by the national webbased environmental screening tool for Cape vultures. The protocol will apply within and outside of the REDZS.
It has been facilitated by a Cape vulture risk map produced by the Fitzpatrick Institute of African Ornithology, which identified areas of very high, high, medium and low sensitivity for collision of Cape Vultures with wind turbines, based on the bird tracking data, terrain, breeding, feeding and behaviour modelling.
“These allowed for the determination of specific requirements for monitoring and risk assessment,” said Mbelengwa.
Where the site sensitivity verification has confirmed it as being of a high or very high collision risk to Cape vultures, an additional 12-month monitoring regime must be implemented, which considers the ability to mitigate this.
“Where impacts are not able to be mitigated,
the site will not be suitable for the development of a wind energy facility …
“The protocol identifies that an approval granted is subject to adaptive management, which could include curtailment and shutdown measures should there be unacceptable impacts on Cape vultures post construction.”