Norwegian researchers have revealed a brand new examine exhibiting that the area between photo voltaic panels and rooftop surfaces would possibly play a crucial function in contributing to PV system fires.
Rise Hearth Analysis AS, an institute in Norway, has performed a sequence of experiments indicating that the gap between photo voltaic modules and rooftop surfaces could possibly be an important consider PV system fires.
“We’ve got not discovered any single excellent distance between the roof and the PV modules that may forestall fireplace propagation,” researcher Ragni Fjellgaard Mikalsen informed pv journal. “However we now have seen that the hole distance is considered one of a number of parameters that have an effect on the fireplace unfold.”
The scientists said that wind pace and air hole dimension may have an effect on the event of fires within the area between photo voltaic modules and the underlying roof constructions. In addition they checked out how fires may have an effect on PV methods on actual, pitched rooftops in Norway. They carried out 29 experiments on the institute’s facility in Trondheim in 2021.
The analysis group recognized a hyperlink between the dimension of the hole between a rooftop floor and the modules, and decided how huge an preliminary fireplace must be for the blaze to unfold and turn into bigger.
“These, and different experiments, level to {that a} bigger hole distance decreases the flame propagation, however different parameters, like inclination, ignition supply, flamable supplies also can have an effect on the fireplace dynamics within the air hole,” mentioned Fjellgaard Mikalsen.
He claimed that there are not any testing strategies or requirements that correctly contemplate the interaction between PV modules and constructing surfaces.
“The take a look at strategies for constructing supplies will not be together with the likelihood so as to add PV modules, and the take a look at strategies for PV modules will not be contemplating what constructing floor they need to be put in on,” he mentioned. “For constructing built-in PV modules, the modules have to adjust to each the laws for constructing supplies and as {an electrical} set up.”
He mentioned that the modules had been examined in opposition to one of many 4 European take a look at strategies listed in CEN/TS 1187, however famous that these take a look at strategies will not be significantly well-suited to check PV modules.
“The American take a look at normal UL 1703 / UL 61730 contains some fireplace assessments the place the mixture of roofing materials and PV set up is dealt with,” he mentioned. “These are primarily based on the take a look at for roofing supplies UL 790 the place the roof is uncovered to an exterior flame.”
The scientists mentioned that future requirements for Norwegian PV installations needs to be harmonized on a European stage, and ideally globally.
“Ideally, the take a look at requirements ought to contemplate the interactions between the constructing floor and the PV modules and take a look at the methods at a sufficiently massive scale to incorporate the necessary particulars of the constructing floor, fixing system and PV modules,” Fjellgaard Mikalsen mentioned. “To have the ability to doc the fireplace efficiency of various combos of roofing supplies, fixing methods and PV modules, a structured classification scheme could possibly be developed.
An analogous examine, revealed by the College of Edinburgh and the Technical College of Denmark, confirmed comparable outcomes. The scientists analyzed fire dynamics and flame spread on the substrate beneath panels. They concluded that the shorter the gap between the panels and rooftop, the upper the likelihood of bigger and extra damaging fires.