As the solar energy industry grows in the residential, commercial and industrial sectors, Nationwide is seeing more solar panel installations within the agricultural community. Solar energy is increasingly being used to help farmers, ranchers and other agricultural operations become more efficient, while reducing their impact on the environment.
Harvesting energy from the sun has become a popular option due in part to decreasing installation costs, increased financial assistance programs and other factors. According to the Solar Energy Industries Association, Q3 2014 represented the second largest quarter ever for solar installations in the U.S., which had more than 49,000 installations. This performance represents 41% growth over Q3 of last year. Year-over-year, the national average price for a photovoltaic (PV) installed system declined by 11%.
If you’re utilizing or considering a solar energy system as an alternative means of electrical generation, it’s important to understand the dangers and risks of installing and maintaining a solar energy system, and to follow industry best practices to help prevent costly incidents.
The dangers of solar panels and electric shock and fire
As we have seen with new and developing technologies, there can be growing pains associated with manufacturing defects, improper installation methods and lack of adequate maintenance — which can lead to electric shock and fire.
Firefighters have learned there are potential electrical shock hazards because the photovoltaic (PV) panels do not have an on/off switch at the panel. Once the covers have been removed from the solar panel array, PV cells generate electricity that is collected and used either on the premises and/or directed to the utility electrical grid for electric bill reductions. There are live electrical lines between the PV panels and the isolation switch which could be 20 yards away or more.
During a 2013 fire of a 2-story office building in Wisconsin, the utility company was asked by the fire department to measure the voltage of the metal roof having roof-mounted PV panels. It was reported that the metal roof was about 50 volts, which is considered life-threatening. There have been other similar incidents where fire-fighting efforts were delayed due to the potential for electric shock.
In 2011, a fire on the roof of a factory building in North Carolina involved about 20 solar panel arrays. Results of the incident investigation by the PV installation owner (Duke Energy) were shared with the Solar America Board for Codes & Standards in an effort to prevent similar occurrences. The investigation results noted a malfunction of the solar panel array caused short circuits due to “blind spots” that created heating and eventual fire ignition. A “blind spot” on a PV panel could be considered a manufacturer’s defect, similar to lithium ion battery concerns. (The Federal Aviation Administration restricts Li-ion batteries from checked luggage if not in its device — Jan. 2014).
Investigation results of a 2013 fire at a sprinkler-protected warehouse in New Jersey haven’t been released to the public, but 7,000 roof-mounted solar panels on a 300,000 square foot structure were reported to be a total loss (building and contents).
In addition to the potential for fire ignition and electric shock hazard and fire, roof-top solar panels pose structural concerns to roofs not designed for additional loads. Additional roof loads include, but are not limited to: weight of the PV panels and associated equipment (ballast), snow and ice that can accumulate on the PV panel and in the space between the roof surface and bottom of the PV panel (e.g., wind-blown snow), and altered wind loading of the roof due to PV panel orientation and attachment methods.
Solar panel installation best practices
The Solar America Board for Codes & Standards provides industry best practices and documents to assist PV system installation owners with monitoring and maintenance measures to prevent adverse situations. Other resources include the manufacturer’s literature of PV systems (owner’s manual) and NFPA 70 National Electric Code.
Also, when working on a roof, firefighters are being instructed to use light-darkening tarpaulins to cover PV panels, along with other tactical measures, in order to reduce the electrical shock hazard. Pre-emergency planning with the fire department has been, and always will be, a high priority risk management strategy.
Nationwide’s Property Engineering Group (PEG) and other representatives are available to assist with your risk management efforts concerning solar panel installations, as well as other perils to life and property.