Planned wind farms could endanger birds
CAPE TOWN — Lesotho’s proposed first wind farms could put the southern Africa nation’s bearded vulture population at risk of collision with turbines if the project’s current sites are maintained, a study suggests.
Lesotho is planning its first ever largescale wind farms developments, with two wind farms consisting of 42 and 100 turbines respectively proposed, according to a statement from the Percy Fitzpatrick Institute of African Ornithology at the University of Cape Town (UCT) in South Africa.
Longer-term plans are to set up multiple wind farms throughout the Lesotho highlands, with a goal of producing about 6,000 megawatts from up to 4,000 turbines, adds the statement.
The bearded vulture Gypaetus barbatus, faces extinction in the southern Africa region, with only about 109 breeding pairs confirmed to be alive, their population having declined by more than 30 per cent in the past five decades, according to the British Ecological Society.
Researchers from Scotland and South Africa are hoping that the map will help wind farm developers in Lesotho and surrounding South African provinces site turbines away from areas used by bearded vultures.
The map is part of a study published on 24 June in Journal of Applied Ecology.
According to the study, 21 bearded vultures of different ages were fitted with solar-powered GPS (Global Positioning System) satellite tags from 2009 to 2013 and data collected in Lesotho were used to create models. The models were further refined by incorporating flying heights at risk of collision to predict areas prone to impact with wind turbines.
The tags generated data, logging the vultures’ location, altitude and speed every hour during daylight, leading to the development of different models for birds of different ages.
“The current proposed areas … have the
potential to cause the most damage to the [vulture] population through collisions,” the researchers write in the journal. “Altitudes of fixes of adults and non-adults showed that they spent 55 per cent and 66 per cent of their time, respectively, at heights that placed them at risk of collision.”
Arjun Amar, co-author of the study and a senior lecturer at the South Africa-based Percy Fitzpatrick Institute of African Ornithology, UCT, tells Scidev.net: “We don’t want to stand in the way of development, but [we] hope the maps will be used to promote sustainable development,”
Research at wind farms in Spain and North America had shown that vultures were vulnerable to the rotating blades of turbines, so it was important for energy technologies to be deployed with proper planning, design and risk assessment, Amar explains.
Samantha Ralston-paton, birds and renewable energy manager at Birdlife South Africa, who was not involved in the study, adds: “It is a great study and really important work.” Ralston-paton notes that the study has tried to address environmentalists concerns on the suitability of the Lesotho highlands for developing wind energy.
According to Ralston-paton, the data could convince the Lesotho government, wind energy developers and financiers to carefully consider the available options in terms of where best to place renewable energy infrastructure, and what technology is best for the environment.
“We encourage the development of renewable energy, but it must be environmentally sustainable,” Ralston-paton adds.
LESOTHO is a prime location for wind energy production because of its elevation.