Fire is a major cause of accidents in wind turbines, according to research involving Edinburgh engineers.
Researchers carried out a global assessment of the world’s wind farms, which amount to an estimated 200,000 turbines.
The team, from Imperial College London, the University of Edinburgh and SP Technical Research Institute of Sweden, estimate that more than 117 turbine fires take place each year.
The main causes of fire ignition in wind turbines are lightning strike, electrical malfunction, mechanical failure, and maintenance errors.
In 90 per cent of cases, the fire either leads to substantial downtime or total loss of the wind turbine, resulting in economic losses.
Turbines catch fire because flammable materials such as hydraulic oil and plastics are close to machinery and electrical wires. These can ignite if they overheat or are faulty.
Oxygen in the wind can quickly fan a turbine fire.
Once ignited, chances of fighting the blaze are slim owing to their height and typically remote location.
Fire has accounted for 10 to 30 per cent of reported turbine accidents since wind farms were first constructed the 1980s, the team discovered.
Each wind turbine costs in excess of £2 million and generates an estimated income of more than £500,000 per year. Loss or downtime can impact on the industry.
The researchers suggest a number of protection measures to prevent or minimise fires.
These include lightning protection systems, use of non-combustible oils, and in-built heat barriers.
Smoke alarm systems inside the turbine, and suppression systems that quickly douse any flames in water or foam, are also recommended.
The research is published in Fire Safety Science.