The use of photovoltaic (PV) systems to generate clean sustainable energy is well established within the built environment, with installations becoming more of a ‘norm’, rather than an exception. However, the installation of PV systems to a building can introduce new hazards which may increase the likelihood or severity of a loss. Data obtained by The Independent in 2023 indicates a rise in the number of fires (opens a new window) involving solar panels, with six times the number in 2022 compared with 10 years earlier.
Such losses are not restricted to residential buildings and can also impact commercial properties. An example being a fire in a 45,000 m (opens a new window) in Peterborough, UK, in Feb 2024, requiring over fifty firefighters to bring the blaze under control.
It is important, therefore, to ensure robust property protection principles are adequately considered throughout the full project lifecycle of a PV system to ensure any hazards are identified, assessed, and controlled.
PV Systems
PV systems consist of semiconductor materials encapsulated by glass and a polymer/glass backing, which generate direct current (DC) when exposed to sunlight. An inverter is used to convert this power to alternating current (AC) current for practical use by the facility or transferred to the grid when power exceeds use. Systems are typically ground mounted (generally preferred by property insurers) or roof mounted secured with mechanical fixings or ballast.
Common property hazards to be assessed when considering the installation of roof mounted PV systems include:
Fire | PV systems introduce new electrical components such as wiring, invertors, control equipment as well as the PV panels themselves. These components can be subject to failure, damage, or heating, increasing the risk of fire. Systems can also be damaged from external fire exposure. |
Windstorm | PV systems can be damaged from wind or other debris if not adequately designed/installed. |
Hail | PV systems can be damaged from hail exposure if sufficient resistance is not provided. |
Snow / rain | Roof damage can result from excessive load of snow/rainwater combined with the weight of the PV system. |
Earthquake | PV systems can move in the event of seismic activity resulting in damage and the potential for fire. |
The installation of a PV system can introduce new components which may increase the likelihood or severity of a loss. Examples influencing the likelihood include:
Electrical wiring faults (loose, damaged, or inappropriate connectors). Connectors are reported to be a common source of PV system fires. A 2017 study (opens a new window) identified PV DC connectors, inverter and DC isolators accounted for 84% of PV system related fires.
Overheating or failure of PV modules or inverters
Examples influencing the severity include:
The PV system altering the fire behaviour of the roof, increasing the spread of fire and/or restricting firefighting efforts.
A PV system fire damaging the roof cover resulting in firefighting water entering the building damaging equipment and stock below.
PV system design approach
A range of property protection guidance for the design, installation and management of roof mounted PV systems is readily available. Such guidance may sometimes exceed requirements of local building regulations. However, the implementation of robust property protection principles reduces the likelihood of a large loss, improves business resilience, and should be considered more favourably by property insurers.
Example guidance includes:
Consult your broker and insurer at an early stage to agree on an acceptable solution for all stakeholders.
A key consideration is the planned location of any roof mounted PV system. Carefully consider existing or proposed roof construction materials, penetrations, and equipment, avoiding installation on combustible roof systems. Thermal barriers can help mitigate the influence of an existing combustible roof structure in some circumstances. Other considerations include the age and condition of the existing roof (it is harder to repair or recover a roof once a PV system has been installed) and avoiding installation of PV systems on roof areas over high value or business critical operations which may be susceptible to water damage.
The development of a corporate policy on the design, installation and management of PV systems helps guide implementation of best practice throughout the lifecycle of the installation, including:
Concept: Identify and agree best practice principles to guide the suitable location of PV systems (including roof upgrades where needed), suitable structural analysis of roof areas, identification and mitigation of hazards (both fire and natural hazards), review and suitability of electrical infrastructure and selection of suitable contractors. For example, those accredited to a national trade body and working to suitable standards. In the UK this might include the MCSCertification Scheme Requirements or UK BS 7671 IET Wiring Regulations 18th edition or later.
Design: Apply local building, electrical and fire codes in addition to the property protection principles agreed with your broker/insurer. Select suitable PV components and protection systems such as fire detection, surge protection, plus fire control/suppression and lightning protection where needed.
Installation: Ensure installation work is conducted in accordance with suitable requirements such as the MCS and IET PV Code of Practice in the UK. Ensure the installation is conducted in accordance with the design, utilising an appropriate quality assurance process and representative.
Operation: Ensure inspection, testing and maintenance of the PV system is conducted in accordance with local requirements and manufacturers guidelines. Ensure any changes are controlled through a management of change process.
Planning for emergencies: Update the site emergency plan to include events involving the PV system and associated components. Ensure drawings are updated with key information including location of PV systems, isolation points, access, and fire water supplies. Collaborate with the local fire brigade, sharing information and developing pre-fire plans.
The documents referenced above provide additional guidance.
With the ongoing focus on clean energy, the installation of PV systems will continue to grow. There are positive aspects to such systems, but the potential risks need to be considered and managed. For further information, please visit the Lockton Risk Control page (opens a new window), or contact your broker or insurer.
