Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Program – Fire Prevention and Safety Grants, Underwriters Laboratories (UL) examined fire service concerns of photovoltaic (PV) systems and the potential impact on firefighting operations. These concerns included firefighter vulnerability to electrical and casualty hazards when mitigating a fire involving photovoltaic (PV) systems. The need for this project is significant due to the increasing use of photovoltaic systems, growing at a rate of 30% annually. As a result of greater utilization, traditional firefighter tactics for suppression, ventilation and overhaul have been complicated, leaving firefighters vulnerable to potentially severe hazards. Though the electrical and fire hazards associated with PV systems have been known for some time, a very limited body of knowledge and insufficient data exists to understand the risks to the extent that the fire service has been unable to develop safety solutions and respond in a safe manner.
This fire research project developed the empirical data that is needed to quantify the potential hazards associated with fire scenarios involving PV installations and provides the basis for the development of firefighting operational practices to reduce firefighter death and injury.
A functional PV array experimental fixture was constructed outdoors at UL’s Northbrook, IL campus. This fixture provided for experiments to:
- Develop knowledge of the hazard of the application of water to PV installation during suppression tactics.
- Generate understanding of effective de-energizing practices such as deployment of salvage tarps and limitations of disconnect devices.
- Address concerns about power generation during low and artificial light conditions.
In addition, experiments were conducted on functioning PV arrays at Delaware County Emergency Service Training Center. A series of experiments were conducted on three PV technologies – metal framed glass on polymer, flexible laminate, and building integrated roof shingles. Fire experiments were designed to represent a room of content compartment fire which evolved to a structure fire ending in collapse. Experiments were also conducted on a rack mounted PV arrays to represent a debris fire under the PV modules above the roof. Following the fire experiments, the PV modules were examined to determine their ability to generate power representing potential safety hazards for firefighters, particularly during overhaul operations.
The results of these experiments provide knowledge for the fire service for them to examine their thought processes, standard operating procedures and training content. Several tactical considerations were developed utilizing the data from the experiments to provide specific examples of changes that can be adopted based on a departments current strategies and tactics.
Read the full report HERE (PDF).