By Angela Krcmar, Global Sales Manager, Wind, Firetrace International
Fire is one of the most expensive losses for any wind farm owner and operator to manage. Beyond the potential devastation of the turbine, fires pose a serious hazard to human life and the environment. As such, the wind industry is already taking action to prevent fires and their spread, adopting strategic and technological solutions in order to ensure safer operations.
However, despite this ambition, the wind industry has been hindered by its own unwillingness to share data on fire incidents when they happen. Currently, while a handful of U.S. states mandate that all fires are reported to local authorities, this reporting lacks detail about the precise nature and cause of the fire. This lack of in-depth incident data prevents the industry from not only understanding the frequency of wind turbine fires, but whether current turbine designs or operational best practice expose owners and operators to greater risk.
Evolving risks based on expert testimony
Despite a lack of transparency around fire incident data, a few key risks have been identified from experts in the field. As designs have adapted to protect against environmental hazards like lightning, internal, mechanical or electrical failures causing sparks have become an increasingly common source of fire.
The risk of these mechanical or electrical failures occurring increases depending on turbine age and the number of skilled technicians available to perform maintenance. Overall, around 7% of the current wind fleet is now over 15 years old – a figure much higher in Europe and North American due to the maturity of the sector. Additionally, while there are now more than 60,000 turbines totaling 109.9 GW spinning in the United States, there are only around 7,000 technicians to manage that fleet. This gap between number of technicians and turbines increases the likelihood that a number of assets will simply lack regular and thorough maintenance, resulting in the accumulation of mechanical and electrical defects.
The changing climate, particularly along the West Coast, has created arid conditions that increase not only the risk that a spark will become a fire, but the likelihood of that fire growing and spreading into the environment. Electrical sparks in poorly maintained transmission lines have already resulted in wildfires that have caused untold damage to communities – and ultimately bankrupted the utility following litigation.
It is therefore vital for the wind industry to take steps to manage these risks and prevent the spread of any fires that do start.
Best-practice in design and operations to reduce fire risk
One of the first steps to reducing fire risk is to start with the turbine itself. While most turbines have been designed to reduce the risk of fires starting, some components can either increase the likelihood of sparks or increase the damage that a fire can cause.
For example, as turbines have grown in size for increased megawatt capacity, a number of manufacturers have opted for carbon blades to further decrease the weight without sacrificing strength in the face of high windspeeds. However, while these blades generally increase the lifetime of an asset, they still pose a significant hazard in the event of a fire, as carbon composite dust can be more explosive than previous designs.
Similarly, tower cables are necessary to transport electricity from the nacelle to the grid and cannot be designed out. However, while cable materials are difficult to set alight, if enough heat builds up at a splice, then a fire can start.
Faulty electrical transformers are a common root cause of wind turbine fires due to arc flashes – and if located in the nacelle, can cause total destruction of the asset.
As such, systems to monitor, protect and suppress fire are necessary to keep all the benefits of component improvements like use of carbon blades and higher turbine output while minimizing fire risk. Owners and operators can ask their manufacturers to install these systems ahead of project construction or choose to retrofit them currently operational projects.
However, beyond the asset itself, there are a number of steps that can be taken at the O&M level to reduce fire risk. A common practice that can increase risk of fires is remote turbine shutdown and start-up – before a turbine is switched on again, technicians must first determine what the initial error was and whether restarting the turbine would result in another failure or sparks.
In order to ensure up-to-date best practice and allow for benchmarking between different strategies, the industry must take steps toward transparency. Once fire data is accessible, owners and operators can make more effective decisions around the level of fire protection needed to prevent significant financial and reputational losses.
Angela Krcmar has over 10 years of experience in the fire protection industry focusing on the renewable sectors including wind and battery storage. For the past 10 years Mrs. Krcmar has led Firetrace efforts in the wind industry, contacting and visiting wind farms, owners and manufacturers in an effort to discuss needs and advantages of fire protection for wind applications. With the increases in the size and value of turbines, the cost of potential equipment losses, employee safety, downtime and increases in insurance premiums the need for fire protection is rapidly being recognized and owners, operators and manufacturers are now exploring their options.
Mrs. Krcmar is an active member of the AWEA Wind Environmental, Health, and Safety Standards Committee Meeting, member of the NFPA 855 Committee for Standard for the Installation of Stationary Energy Storage Systems and contributing member of the UL 6141 technical standards panel.