The wind energy industry is one of today’s leading industries in the renewable energy sector, providing an affordable and sustainable energy solution. However, the wind industry faces a number of challenges, one of which is fire and that can cast a shadow on its green credentials. The three elements of the fire triangle, fuel (oil and polymers), oxygen (wind) and ignition (electric, mechanical and lighting) are represent and confined to the small and closed compartment of the turbine nacelle. Moreover, once ignition occurs in a turbine, the chances of externally fighting the fire are very slim due to the height of the nacelle and the often remote location of the wind farm.
Instances of reports about fires in wind farms are increasing, yet the true extent of the impact of fires on the energy industry on a global scale is impossible to assess. Sources of information are incomplete, biased, or contain non-publically available data. The poor statistical records of wind turbine fires are a main cause of concern and hinder any research effort in this field. This paper aims to summarise the current state of knowledge in this area by presenting a review of the few sources which are available, in order to quantify and understand the fire problem in wind energy. We have found that fire is the second leading cause of catastrophic accidents in wind turbines (after blade failure) and accounts for 10 to 30% of the reported turbine accidents of any year since 1980’s. In 90% of the cases, the fire leads to a total loss of the wind turbine, or at least a downtime that results in the accumulation of economic losses.
The main causes of fire ignition in wind turbines are (in decreasing order of importance): lighting strike, electrical malfunction, mechanical malfunction, and maintenance. Due to the many flammable materials used in a wind turbine (eg. fiberglass reinforced polymers, foam insulation, cables) and the large oil storage used for lubrication of mechanical components, the fuel load in a turbine nacelle is commonly very large. The paper finishes with an overview of the passive and active protection options and the economics (costs, revenue and insurance) of wind turbines to put in context the value of a loss turbine compared to the cost and options of fire protection. We hope that this paper will encourage the scientific community to pursue a proper understanding of the problem and its scale, allowing the development of the most appropriate fire protection engineering solutions.