26 March 2024

Solar Fire Risks - Six pressure points to consider when it comes to fire risks

Submitted by: Teresa Settas
Solar Fire Risks - Six pressure points to consider when it comes to fire risks

South Africa has seen a surge in the adoption of residential and commercial solar power generation, much of which can be attributed to the escalating challenges posed by increased load shedding as power utility, Eskom, struggles to meet the country’s demand for reliable electricity generation.

South Africa added 2 965 MW of installed solar in 2023 alone, out of the continent’s 3 745 MW added. South Africa has at least 7 781 MW of solar installed, representing almost 47% of all installed capacity on the African continent.[1]

At the heart of this solar revolution lies photovoltaic (PV) technology, where semiconducting materials harness light to release electrons, generating a crucial current for power generation. Encased in a transparent bonding material such as Ethylene Vinyl Acetate (EVA) and fortified with a sheet of glass and aluminium framing, PV panels stand as the vanguard of sustainable energy solutions. However, as the solar industry expands, so do the challenges and risks.

“Fire hazards are a considerable threat to solar power generation and battery energy storage,” says Andy Mizen, a senior risk consultant at Aon South Africa. “Environmental conditions, ranging from hail and wind to flooding, can wreak havoc on the infrastructure while the allure of PV panels to thieves, coupled with rising manufacturing costs, contributes to the upswing in insurance expenses. The complexity intensifies when solar installations are located on rooftops due to the concentration of electrical sources of ignition such as roof insulation and cabling, making timely intervention, maintenance and emergency responses crucial,” Andy explains.

Aon delves into the six most prolific challenges that solar plants are faced with:

1. Construction risks

PV panels must be installed by a qualified engineer according to a recognised standard and according to the manufacturer’s instructions.  To reduce the associated fire risk, the panels must be mounted on a non-combustible base such as concrete, with the framing designed to reduce the risk of wind, hail or lightning damage. The best approach is a secure steel structure, which also allows for the possibility of including a tilting mechanism in the design not only to track the movement of the sun for optimal production, but also to counteract the potential for hail risk.

2. Documentation

  • It is important to insist on electrical, earthing and cabling schematics In the lead-up to the installation.
  • Mounting designs, as-built drawings, mechanical drawings and a commissioning manual are also important.
  • Once the project is complete, it will need an electrical Certificate of Compliance (CoC) and engineering sign-off, which is critical from an insurance perspective to prove that the work was completed according to the required electrical and structural standards.

3. Fire risk

Any solar installation poses a potential fire risk which is why it is important to ensure that there is sufficient spacing from any combustible storage and roof underlay material, which must be confirmed as non-combustible. Cabling should also be fire-resistant and located away from critical components where possible. The location of your installation is paramount to allow the fire brigade access to the panels, quickly and safely, and to also check that hydrant water pressure can reach the panels, especially when mounted on structures such as a roof. Always have suitable fire extinguishers onsite as your first line of defence and implement a strict no-smoking policy across the board.  This is especially important where lithium-ion battery storage is installed - Aqueous Vermiculite Dispersion (AVD) is an extinguishing agent for use on Lithium-ion battery fires which cannot rely on cooling alone, but also need to contain and encapsulate the battery to limit the reaction, contain the gases and prevent access to external oxygen, so the risk of the fire spreading is reduced.

4. Security

The energy generation site needs to be protected from the risk of arson and theft or any unauthorised access, by means of robust perimeter control and diligent security. It is also pertinent to have security staff aware of NFPA601 (standard for security services in fire loss prevention) patrol requirements specific to fire loss prevention, while including machinery spaces and isolated areas into their patrol regime.

5. Power supply

To ensure optimal safety measures, it is imperative to establish a clearly designated electrical isolation point for emergency use by the fire brigade. This point should facilitate an immediate and controlled disconnection from the electrical grid. Additionally, a robust system is required to generate an alarm signal to a 24/7 manned control centre, serving as an early warning mechanism in worst-case scenarios.

Emphasising a proactive approach, solar farm substations and transformers must be situated within an environment equipped with a gaseous fire suppression system, monitored fire detection and sufficient separation from panels. Given the potential heat accumulation in a PV array system and inverter, installation in a well-ventilated area is crucial. The incorporation of drip trays or bunds, capable of containing 110% of the liquid utilised in solar power generation, is essential to prevent the spread of oil onto hot components. Regular inspections for any damage are necessary to mitigate risks.

Adhering to industry standards, the replacement of batteries used for electricity storage every three years is considered a fundamental practice in preventing potential issues. Prioritising prevention over cure remains paramount in maintaining the safety and reliability of solar power systems.

6. Maintenance

Good housekeeping of a solar solution Includes:

  • Cleaning dust from the panels, to control any surrounding vegetation to reduce wildfire risk and ensure storm water channels are cleared of debris and vegetation.
  • Conduct annual thermography surveys for fault-finding purposes.
  • It is important to comply with the manufacturer's recommendations and to follow instructions meticulously. 
  • Regularly inspect concrete bases, panel connections, cables and structural steel supports, especially after high winds or other climactic conditions.
  • All construction and maintenance work must be subject to strict permit conditions, including work at height, electrical lock out tag out and hot work.
  • Ensure staff are provided with suitable training by requiring a permit to work, perform any maintenance or manage sources of ignition.

The establishment and operation of solar plants are undeniably transformative for our energy landscape, yet they are not without their formidable challenges. By implementing comprehensive risk mitigation measures that address these challenges, stakeholders can not only enhance the resilience of solar farms but also safeguard their long-term sustainability.