Fire departments in the Valley deal with numerous challenges every day, but a new challenge — dealing with an increasing number of residential solar systems in the state — demands extra training and increased vigilance.
Residential solar power systems are a growing trend in the Valley and across Arizona. With hundreds of new solar systems installed each year, and the recent agreement to limit the fees solar users pay to the utilities, more solar companies are interested in the state and more systems are sure to come.
These systems present unique dangers and challenges to firefighters. The photovoltaic cells that make up the solar panels are a live circuit producing a live electrical current that cannot simple be turned off like a traditional grid-powered electrical connection. That means whenever fire crews need to go on the roof for access, venting or to apply water to a growing fire, extra precautions must be taken.
“The thing is identifying it early, making sure we secure the system … but you can’t turn the system off,” said Keith Welch, battalion chief of the Chandler Fire Department.
He said because solar systems are still tied to the outside power grid, and in different ways depending on the power supplier, fire crews must be cautious in making sure that the outside grid connection is properly severed as well. Even then, the system is still live because the panels, powered by the sun, can’t be simply turned off.
Although engineers calculate the weight of the panels and the load-bearing capabilities of the roof, the extra weight becomes an added concern when sending firefighters into a structure, especially into the attic or top floor. The added weight can cause a structure’s roof to lose integrity more quickly than otherwise.
Welch also said the panels also block water access to the roof of a burning structure. Besides the obvious difficulty of spraying water onto a live, and possibly damaged, electrical circuit, the panels prevent the water from reaching the actual roof. In some cases, he said, crews must wait for the structure to partially collapse in order to get water around panels and into the structure.
So what do local fire departments do about these situations?
“Within the Mesa Fire Department, we have not put forth a specific policy on that yet. We are in the process of that,” said Mike Vitale, a Mesa firefighter, adding that the policy would have to go through other departments as well and be vetted for compliance with national safety standards.
Vitale said that safety precautions begin with securing utilities. Generally, this is a very simple procedure as the controls are clearly marked and crew members know where to look for them. The challenge comes when, as allowed by some local codes, the cutoff switch for the solar energy system is located inside the house, often in the garage. In the event that the fire was localized to, or had spread to, that area, it could present a considerable challenge. Also, when a fire happens at night, panels located out of sight or not on the front slope of the roof could be missed in a cursory inspection, leaving crews without the knowledge that a solar energy system is even present.
He said crews deal with the difficulties of the added weight of the panels by paying even closer attention to the roof.Safety officers and battalion chiefs on the outside keep a watchful eye on the roofline to ensure that the crew is out before there is any threat of roof failure.
The construction of a home plays into this as well. An older home with the generally sturdier build commonly used in the past will afford the crew more time inside to fight the fire and even secure valuable possessions like laptops or old photos.
“We do our best to do a very rapid search, but very thorough, and try to get people out of there,” said Vitale. “You’d be amazed at how many times we find those things and are able to cover them. Your insurance company can replace your house; they can’t replace those things.”
Contact writer: (480) 898-6581 or firstname.lastname@example.org