The challenges and risks of solar panels
06/17/2021
Why are solar PV panels installed on buildings?
Along with many other countries worldwide, the UK is increasing the amount of energy it obtains from renewable sources in order to meet global commitments on climate change. The aim being to reduce reliance on fossil fuels for energy production, thereby reducing carbon emissions.
One of the most popular “green energy” initiatives is the production of electricity from solar energy using photovoltaic (PV) panels, or solar panels as they are more commonly known.
Large amounts of electricity can be produced from “solar farms”, consisting of banks of PV panels, sited in an open-air environment, angled to collect the sun’s energy. From a property insurance perspective, these systems are normally located in the countryside, away from any significant buildings or valuable structures. Where space is at a premium, however, solar PV panels are often installed on building rooftops, or integrated as part of the building structure.
It is now relatively common to see solar PV panels on rooftops of houses, apartment blocks, public buildings and commercial/industrial buildings. The electricity produced can be consumed directly by the building occupiers, with the excess power exported to the national grid.
Solar energy brings many positives from a climate change perspective, but installing solar PV panels on building rooftops can introduce new risks to the building and occupants.
Fires resulting from electrical faults is the most common cause of loss associated with roof mounted solar PV installations. In some cases, the fire has led to total destruction of the building and all contents.
Challenges arise from the varying quality of installation. Whilst solar PV products must meet UK quality assurance standards, there are currently no regulations covering installation.
Some key issues which are often not adequately considered are:
Solar PV panels generate electrical energy in the form of direct current (DC). Whilst a competent electrical contractor should be well versed at working with normal alternating current (AC) systems, many lack the necessary knowledge/experience working with DC installations.
Solar PV systems are all too often overlooked when it comes to periodic electrical inspection and maintenance. Zurich has encountered instances where PV systems have never been checked since the day they were first installed.
Solar PV panels generate electrical energy for the entire time they are exposed to natural light. This means the panels and associated electrical equipment feeding power to the building remain “live” at all times. This poses serious safety risks to persons in the immediate vicinity, and to fire fighters in the event of a fire as the system cannot be turned off, unlike conventional electrical supplies.
A recent fire loss
The pictures below are from a recent claim handled by Zurich. They show the significant structural damage following a fire that began at an array of solar panels. The picture on the left indicates the early stages of ignition are relatively confined. However, the swift spread of fire, fuelled in part by the additional combustible roof elements, led to the extent of damage seen on the right.
What can be done to mitigate the fire risks?
Building owners/occupiers should have a basic understanding of the technology and how it works.
Consider how a PV installation will impact on the building throughout the building’s lifetime.
For new builds, ensure co-ordination between the roofing company and the PV designer/installer. Ideally the same person/company.
Consider how the power generated will be used on site and exported via the grid connection.
Install only on non-combustible roofs (ideally). Do not install a PV system on a roof containing highly combustible materials, such as polystyrene insulation.
Ensure the system is designed and installed by competent contractors, adhering to industry best practice and regulations.
Allow access for roof maintenance and cleaning. Assess how roof / PV panel sections will be replaced.
Ensure the PV system is suitably maintained as part of the building’s electrical inspection and testing procedures. Far too often PV systems are overlooked in this regard as mentioned earlier.
Have an emergency response plan in place in case a fire breaks out and keep it up to date. Incorporate this with the building’s fire risk assessment.
Consider fire brigade access and facilities, including system information. This should include an easily accessible DC isolator switch/circuit breaker or "fireman switch" to enable the current from the PV panels to be isolated remotely - often these switches are sited in lofts/roof spaces where the fire brigade cannot operate them in an emergency. The inability to isolate the supply of electricity from the panels to the building may delay firefighting operations as the electrical system within the building can remain energised.
For more information consult your usual Zurich contact or insurance advisor.
