South Wales Evening Post
Walker fears after collapsed turbine ‘spinning too fast’
AN IN-BUILT safety system designed to bring a wind turbine to a safe stop failed and ultimately led to its collapse at a Welsh wind farm, it’s been confirmed.
The 300ft Nordex-designed wind turbine crashed to the ground at Gilfach Goch in February this year, becoming separated from its base and completely destroying its blades.
Now regional MS Altaf Hussain has challenged the Health and Safety Executive about the dangers presented to walkers and others from wind turbine failures.
He has taken this action because of fears in Maesteg, Bryn, Cwmavon and nearby communities about the risks posed to residents if the proposed Y Bryn windfarm on Margam Mountain goes ahead.
Locals reported hearing loud noises coming from the Pant-y-wal wind farm throughout the night of February 13 before waking up to see the turbine blown over on Monday morning.
An investigation by Nordex has shown the Nordex N90/2500 wind turbine collapsed after running for over four hours in an “overspeed condition”.
The wind farm’s owners Pennant Walters have since removed the turbine components and placed them in storage.
A Nordex spokesman said: “A Root Cause Analysis (RCA) investigation determined that a technical issue, starting within an Uninterrupted Power Supply cabinet for one of the blades, triggered an unprecedented chain of events in quick succession.
“This disabled the main power supply and the backup power supply to each blade of the pitch system, therefore all three blades of the wind turbine were left without power resulting in a fixed state.
“The wind speed conditions on the day increased, putting the wind turbine into an overspeed condition until it collapsed.”
Following the incident, which raised concerns over the safety of wind turbines in Wales, Nordex inspected all the remaining turbines at Pant-y-wal wind farm in Rhondda Cynon Taf.
Any likelihood of human injury was considered to be low and no further action was taken at the farm.
Nordex added: “Temporary measures are being implemented to reduce the likelihood further. A permanent solution is being developed to mitigate the residual likelihood.”
Welsh Conservative Dr Hussain had already written to the HSE about the
February incident. He has now been back in touch for an update on their investigations.
Commenting further, Dr Hussain added: “I have asked HSE if it is recommending any actions by windfarm owners to forestall these failures.
“It is more important than ever to assess the risks wind turbines pose because the country as a whole is likely to be embarking on a new energy strategy which will see an expansion in the number of on-shore wind turbines in a bid to reduce our dependence on foreign gas.”
In her reply, Sarah Albon, chief executive of HSE, said that the investigation into the Pant y Wal incident is still ongoing but she was able to give a progress report.
She said: “We have established that the existing in-built safety control systems designed to bring the turbine to a safe stop in the event of any significant problem, all failed to operate.
“This resulted in the turbine running at twice its designed maximum speed for a period of four hours leading to structural failure and the collapse.”
She explained that the out-of-control condition of the turbine was not recognised by the operator and that this issue is now being addressed by improvements to the monitoring and control systems so that if it recurred, the site operator would be alerted and measures put in place to establish an exclusion zone around the turbine.
She added that HSE is pursuing industry improvements to the safety critical back-up systems to ensure that turbines can be brought back into a safe state should there be a further adverse incident.
These improvements will be adopted by the Pant y Wal operator and the findings of this investigation will be made known throughout the wind turbine sector.
Dr Hussain responded: “I am glad that this incident is being treated seriously by HSE to reduce the likelihood of similar collapses occurring.
“But with a massive new windfarm being proposed at Y Bryn where turbines of up to 800 feet high may be installed, local residents need to be reassured that the risks to people out walking on our mountains in future are understood and that appropriate action to minimise them are taken.”