Almost a third of all wind turbine failures are caused by fires, while more than a hundred wind turbine fires a year are going unreported, research has revealed.
A major international study of more than 200,000 wind turbines installed across the world has revealed that the problem, which in 90% of cases leads to “substantial downtime” or the scrapping of the turbine, is being underplayed because official reports of incidents are either incomplete, biased or kept secret.
Dr Guillermo Rain, from the Department of Mechanical Engineering at Imperial College, said: “Fires are a problem for the industry, impacting on energy production, economic output and emitting toxic fumes.
“This could cast a shadow over the industry's green credentials. Worryingly our report shows that fire may be a bigger problem than what is currently reported.”
The team of researchers examined data from government reports, anti-wind farm lobbyists and media reports produced since the 1990s and found that an average of 11.7 turbine fires are reported each year. The researchers estimate that the actual number is ten times greater – around 117 separate fires each year.
This number is substantially less than the number of incidents in similar energy industries. Thousands of fire accidents are reported each year in the oil and gas industry globally. However, wind turbines can cost in excess of £2 million and generate incomes of more than £500,000 per year. Any downtime or loss of equipment is therefore very costly and affects the sector's viability at this early stage in its development.
According to the research, the number of wind turbine fires being reported is increasing. Fires in turbines are caused by lightning strikes, electrical malfunction, mechanical failure and maintenance error. The turbine nacelles contain a high amount of flammable material, such as hydraulic oil and plastics, in close proximity to machinery such as gearboxes as well as electrical wiring. After ignition, fires are fanned by high speed winds and are often not extinguished due to the remote locations of wind turbines and their inaccessible height.
A reduction in the amount of fires and the damage they cause could be achieved by the use of more passive fire protection systems, suggest the researchers. This includes lightning protection, the use of non-combustible hydraulic and lubricant oils and the inclusion of heat barriers in designs.
Chris Streatfeild, director of health and safety at wind farm trade association RenewableUK, said: “The industry would challenge a number of the assumptions made in the report, including the questionable reliability of the data sources and a failure to understand the safety and integrity standards for fire safety that are standard practice in any large wind turbine.
“There is also a lack of context in the research relating to the actual level of fire risks. Wind turbines are designed to international standards to meet mandatory health and safety standards.
“State of the art monitoring systems ensure that the vast majority of turbine fires can be dealt with quickly and effectively.”
The study, which is titled “Overview of Problems and Solutions in Fire Protection Engineering of Wind Turbines” was conducted by Imperial College, the University of Edinburgh and the SP Technical Research Institute of Sweden.