Managing Emerging Risks – Lithium-ion Batteries and Solar Panels
11/12/2024
Risk management is a constantly evolving discipline. For the past few years, the focus has been on managing the fire risks associated with the emerging challenge of Lithium-ion batteries.
Lithium batteries are now ubiquitous in daily life. They can be found in electric vehicles (EVs), e-scooters, forklift trucks, e-bikes, photovoltaic (solar) panels, and battery energy storage systems (BESS).
Lithium-ion batteries are currently in common use in our homes, businesses, and public organisations right now and the use of them is growing rapidly.
One of the challenges faced by risk managers is that the fire safety guidance and legislation has not caught up with the way Lithium-ion batteries are now being commonly used and stored in many applications. Rather than waiting for fire safety legislation to catch up and be introduced it is essential that organisations are proactive in managing the risks and seek advice and support from an experienced fire protection engineer on the risks and dangers associated with lithium-ion batteries.
What risks are presented by Lithium-ion batteries and solar panels?
Fortunately, Lithium-ion battery fires are rare, but when they do take hold, they can have devastating consequences. The predominate risk associated with lithium-ion batteries is thermal runway.
Thermal runaway is a phenomenon in which the battery cell enters an uncontrollable self-heating state as the cell creates more heat than it can effectively dissipate. Unlike a normal fire, it cannot be extinguished and must be left to burn out.
According to the British Safety Council:
“Batteries will spontaneously ignite, burning at extremely high temperatures of between 700◦c and 1000◦c, and releasing dangerous off gases that in enclosed spaces can become a flammable vapour cloud explosion (VCE).
The temperatures involved and the sparks generated cause a fire, further fueled by the vented gases as the battery cells decompose further, resulting in rapid fire spread. This process happens far more quickly than in any other type of fire.
The reactions, once started, increase so speedily that the cells typically appear to ‘explode.’ Due to the self-sustaining process of thermal runaway, Lithium-ion battery fires are also difficult to quell. Bigger batteries such as those used in electric vehicles may reignite hours or even days after the event, even after being cooled.”
What is the frequency of Lithium battery and solar panel fires?
In 2023, 338 fires involving Lithium-ion batteries were caused by e-bikes, and e-scooters. When it comes to waste, discarded Lithium-ion batteries caused an estimated 201 fires in 2023. And the problem is set to grow; by 2025, around 78 million Lithium-ion batteries will disposed of globally.
Regarding solar panels, from January-July 2023, 66 fires relating to solar panels had occurred in the UK, compared to the 63 fires that were reported for the whole of 2019.
How can Lithium-ion battery and solar panel fires be prevented?
Businesses and organisations such as Local Authorities can safely use EVs, solar panels and battery energy storage systems to help meet their ESG targets provided they take proactive measures to protect both life and property.
These include:
EV charging stations
• Location: If sited externally it is important to ensure there is a minimum 10m separation distance from combustible walls or at least 7.5 m from unprotected openings/extensive glazing in non-combustible walls.
• Firefighting: Provision of access for the Fire and Rescue Service to safely access EV charging areas alongside the provision of suitable fire hydrants for firefighting water.
• Maintenance and Servicing: charging units should be maintained and serviced in accordance with manufacturers recommendations.
For more information see our EV Risk Topic
Roof Mounted Photovoltaic Panels and Systems
• The fitting of PV panel installations to combustible roofs should be avoided wherever possible. An assessment, review and check of the roof suitability of the roof design and structural integrity of the supporting roof (flammable insulation, flammable roof covering, age of the roof system and strength of the roof support system should form a fundamental part of the initial design process.
• PV systems need to be fitted with isolators to disconnect the array / string from the outgoing electrical supply. Additional isolation devices are to be included on inverter and control equipment where DC is converted to AC prior to use in the building or diversion to the national grid. A switch in a prominent location readily accessible to fire-fighters to isolate the DC side of the PV system near the panels to ensure the safety of fire-fighting personnel. This switch should be at ground level, easily accessible and ideally external to the building.
• The Fire and Rescue Service should be advised of the proposed system and design, they should be invited to visit the premises following installation so they can familiarise themselves with the layout and assess how best to tackle any fire.
For more information see our PV Risk Topic
Battery energy storage systems (BESS)
• Ensure the BESS is designed and developed in accordance with NFPA 855 and that the lithium-ion batteries adhere to the UL9540 and UL9540a safety standards.
• Ensure BESS are located a minimum of 30 metres from the main plant or operating premises.
• A competent person should be employed to undertake a site assessment alongside the development of a robust and bespoke documented fire safety strategy to ensure the risks associated with BESS have been fully and adequately assessed.
Wrapping up
Lithium-Ion battery fires pose a significant challenge which can result in major periods of business interruption. A full assessment of the hazards posed by lithium-ion batteries requires a thorough understanding of the mechanisms and risks involved. If the challenges are not fully recognised the protection measures in place may not provide the return on investment expected. A false sense of security may exist if the level of safety is not adequate to protect the risk. Employing a competent person to effectively assess the risks is the best way to meet the challenges associated with lithium-ion battery fires, alongside the appropriate selection of automatic fire and fixed fire protection. The main objective lies in mitigating the risks associated with the devastating consequences of a lithium-ion battery fire so that core business activities are not disrupted.
For more information on anything mentioned in this article please contact Gary Howe, Senior Risk Engineer, Zurich Resilience Solutions on gary.howe@uk.zurich.com
