While few older installed wind turbines have fire detection and suppression, there is a clear trend toward including fire suppression in newer units. Fire incidents, the increasing value of the average turbine, safety issues, environmental impact and local authority requirements are all driving the inclusion of fire suppression systems on wind turbines.
International awareness of fire safety has increased dramatically and, as a result, the National Fire Protection Association (NFPA) developed recommended practices for the protection of wind turbines in the NFPA 850 Recommended Practices. The recommended practices were developed by a committee of manufacturers, power producers, insurers and fire protection professionals who recognize the value of available power and risks associated with certain power production components, with acceptance as of January 2010.
Fire officials and Authorities Having Jurisdiction (AHJ’s) are also now most closely monitoring fire concerns associated with wind power production. These authorities are charged with risk analysis of the wind turbines to ensure crew and community safety while reducing risks of wild land fire.
There are currently no regulations for reporting fire incidents whether large or small, making it far more difficult to offer accurate fire data industry-wide. Regular reports of fire in mainstream media shows dramatic photos of burning turbines. Since August 2011, there have been dozens of catastrophic news of fire incidents with varying causes (i.e. arc flash, electrical malfunction, technician maintenance issues, lightning), all resulting in a total loss and damage to surrounding area.
However, some believe these figures grossly underestimate the scale of the problem. While large fire events may be reported by news organizations, smaller incidents usually go unpublished because there are no required reporting guidelines or a central organization to compile the data. These incidents may not result in a total loss of the wind turbine or nacelle, but do lead to significant costs due to power production interruptions and equipment replacement costs.
The International Association of Engineering Insurers developed a report discussing these challenges. At the IMIA Conference 2009 it concluded that risk of total loss of a wind turbine is high without fire detection and protection systems. Long lead times for replacement parts leading to significant business interruptions was one of the primary concerns and the association found that electrical malfunction was one of the most common sources of these fires.
Finally, fire suppression in a nacelle is a challenge. The environment presents significant issues for detection of the fire and suppression following detection. The air flow, dust, debris, temperature variations and vibration all combine to make traditional approaches to fire detection unreliable, either failing to detect or causing false alarms. The preferred approach is providing modular fire protection systems to areas and enclosures with an inherently elevated fire risk, often containing the damage to the failed component. The limitation of damage enables turbines to be repaired more quickly and returned to service.
By: Scott Starr, Director of Global Marketing, Fire Trace