Our dependence on renewables is growing, and as a result, the wind turbines being built are taller and more powerful. Yet with this growth comes the challenge of keeping assets operational.
The energy matrix is changing and the industry is continuously driving initiatives towards generating greener, cleaner and more sustainable energy. Public support for renewable energy in the UK is consistently high around 85%, and we are proudly now leading the way in reducing carbon emissions to fulfil the Climate Change Act of 2008.
The second leading cause of accidents in wind turbines after blade failure, is fire. It is hence even more vital that we keep them fully operational, and reduce the risks of lives lost and assets damaged, in order to lead in this global movement for greener change. The more renewable we want our energy, the more we must protect our wind turbines.
There are over 340,000 wind turbines around the world, yet the vast majority have no fire suppression system installed.
Striking figures
- 10-30% of all loss-of-power-generation incidents in wind power plants are due to fire.
- The second leading cause of that disruption in wind turbines – after blade failure – is fire
- The total cost per fire incident is estimated at $4.5m.
- 90% of wind turbine fires result in total loss of the turbine or severe structural failure.
The nacelle operates at a great heat and comprises highly flammable resin fibreglass, with internal insulation. Combined with the possibility of lightning strikes, these very tall turbines (now surpassing 450ft) in exposed locations pose a uniquely high risk and are vulnerable to fires.
Fire lends great danger
The fires in wind turbines not only lead to a loss of business continuity and a negative impact on the company’s reputation but also, most importantly, are a critical safety issue.
When turbines are under construction, or engineers are performing maintenance and repairs, the escape routes are often long and vertical, which in the case of a fire lends severe danger. An example of the other effects of such an event:
- In 2005, a wind turbine powering a Sunderland car factory in the UK caught fire, leading to the total loss and disruption of the nearby highway
- In 2011 a wind turbine fire in Ardrossan, UK caught fire and burning debris was scattered across a long distance due to the strong winds
- In 2012 a wind turbine fire in Lower Saxony, Germany estimated a potential loss of Ä300,000-400,000
- In 2017, a wind turbine caught fire and sparked a wildfire in north-east Wyoming, and burnt nearly 1,600 acres.
The design of a wind turbine, which places the mechanical portion of the turbine nearly 300ft off the ground at the top in the nacelle, means there is no practical way to respond to a fire in these units.
Even a small fire can accelerate quickly in a nacelle that comprises highly flammable resin fibreglass. Internal insulation, which can become contaminated by oil deposits, further adds to the fuel load. Lightning strikes also pose a uniquely high risk due to both the turbines’ exposed locations and their height; turbines are now being built in excess of 450ft.
Strive for safety
We must work collaboratively in the wind industry, to find ways of ensuring we can drive greener energy, whilst minimising the danger to engineers, and surrounding landscape, by enhancing our fire safety.
There are many ways to ensure these fires do not recur. The nacelle should be protected via small gaseous fire suppression systems and rely on them to avoid total loss, to save lives, and protect critical infrastructure before maintenance engineers can get to them. The use of gaseous fire suppression systems dramatically improves response time and reliability.
Maintain the systems
Condition monitoring systems should be implemented and maintenance checks must be completed regularly.
However, it is important to note that such fire extinguishing systems require maintenance to ensure they are fully operational and ready in the event of fire. ISO 14520-1:2015(E) assumes that these systems accidentally discharge and leak. 6.2.4.2 Contents indication: ‘Means shall be provided to indicate that each container is correctly charged.’ Followed by: ‘9.2.1.3 The storage container contents shall be checked at least every six months as follows. a) Liquefied gases: for halocarbon agents, if a container shows a loss of agent in quantity of more than 5% or a loss of pressure (adjusted for temperature) of more than 10%, it shall be refilled or replaced.’
Section 10.5.3.2.2 of the NFPA 850 states that the ‘Maintenance and inspection of total flooding gaseous agent systems and interlocked equipment are critical.’ All systems at some time may be called upon to operate in an emergency situation and may help in saving life and property. It is for this reason that knowledge must be had that the system can operate to their full potential.
Gaseous systems are checked for contents annually because they are pressurised and anything that is dynamic offers risk of loss of contents, but this fails to deal with the probability of discharge or leakage for the 364 days per annum in the interim between certification checks.
Test quickly and accurately
Quick and accurate routine tests can make the greatest preventative difference. Coltraco offers specialist non-invasive liquid level measurement to test the contents of fire suppression systems which are inside the nacelle of the turbine – this is called the Portalevel MAX ultrasonic liquid level indicator. Coltraco works with manufacturers of the fire suppression systems to ensure that the Portalevel MAX is the appropriate tool for wind turbine systems.
Case study
In 2017 a wind turbine manufacturer went to the manufacturer of the fire systems that they install in some turbines for a solution to inspect the fire system cylinders (for agent content loss in case the pressurised cylinders leaked or discharged which would mean insufficient agent to suppress a fire event). This manufacturer had worked with Coltraco on projects for many years and recommended the wind turbine manufacturer to look to Coltraco for a solution. Working with the wind turbine manufacturer HQ, Coltraco Ultrasonics’ flagship product Portalevel MAX (ultrasonic liquid level indicator for testing fire suppression systems for agent contents) was chosen for trials and testing. The Portalevel MAX unit is the most accurate in the world able to identify liquefied gaseous extinguishant levels to +/-1.5mm. These passed and the unit was deemed to solve their issues: giving the ability to regularly inspect and maintain the contents of their fire extinguishing systems.
Delivering Safesites®
Using the Portalevel MAX units wind turbine manufacturers and their customers can protect their valuable assets from substantial fire damage, as well as minimise downtime for maintenance, ensuring cylinders are always full and able to extinguish fires. If we really want to make a global effort in leaning ever more to renewables for our clean energy, we must make this recommendation a mandate and a requirement.
These fires that continue to occur pose a dangerous threat to both business continuity and human lives, and yet they are entirely preventable. More and more wind turbine manufacturers are acknowledging the risk to assets, and fire suppression systems are being retrofitted in existing sites. We must now continue to educate and lead, ensuring that no more lives are lost nor critical assets damaged. There are smart solutions available that enable wind turbine owners and operators to improve their fire safety management and reduce the threats to human life, and business continuity caused by any downtime, hereby diminishing the risk to business reputation.
For more information, go to www.coltraco.com
About the Author
Carl Stephen Patrick Hunter OBE is Chairman of Coltraco Ultrasonics, a high-exporting manufacturer, Chairman of the British Exporters Association, Director-General of the Durham Institute of Research, Development & Invention at Durham University, Director of the Centre of Underwater Acoustic Analysis, Professor-in-Practice at Durham University Business School, Chairman of the Council on Geostrategy Forum, Visiting Fellow of the Royal Navy Strategic Studies Centre and Fellow of the Royal Aeronautical Society and of the Institute of Marine Engineering, Science & Technology
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