- Large scale fire tests reveal BIPV facades can sustain burning even after flames subside.
- Glass type and panel design directly influence breakage, fallout and fire spread.
- Double glazed panels with tempered glass identified as safer option for high rise applications.
A new experimental study in China titled ‘Large-scale experimental study of thermal performance of building-integrated photovoltaic façade in an enclosure fire,‘ has raised important fire safety considerations for Building Integrated Photovoltaic systems, a fast-growing technology widely adopted to improve energy efficiency and sustainability in modern buildings.
Researchers conducted 16 large scale fire tests to examine how different photovoltaic façade systems behave under enclosure fire conditions. The study compared cadmium telluride and monocrystalline silicon BIPV curtain wall systems against traditional glass facades inside a controlled compartment.
The findings show that photovoltaic facades behave very differently from conventional glass systems during a fire. One of the most notable observations was the occurrence of sustained burning within panel interlayers, even after the primary fuel source had been extinguished. This creates an ongoing ignition risk within the building envelope and increases the likelihood of fire spread.
The study also found that the interaction between photovoltaic panels and internal fire dynamics plays a major role in how a fire develops. As panels crack and fall out, new openings are created in the façade. These openings disrupt ventilation conditions, intensify flame ejection and significantly increase heat flux compared to scenarios without façade failure.
Material selection emerged as a decisive factor. Panels made with annealed glass were more prone to softening, deforming and eventually falling out as temperatures increased. In contrast, tempered glass panels tended to fracture and fall out more rapidly due to internal stress characteristics but demonstrated greater resistance to initial breakage.
Temperature differentials across glazing were identified as the primary cause of panel failure. Annealed glass panels failed at relatively low temperature differences of between 35 °C and 59 °C, while tempered glass systems withstood much higher differentials ranging from 207 °C to 273 °C before failure occurred.
Panel configuration also proved critical. Double glazed photovoltaic modules were more effective at limiting the formation of new ventilation openings after breakage, helping to stabilise fire conditions. Single layer systems, particularly those with combustible interlayers, contributed to delayed but more extensive opening formation, further influencing fire development.
The fallout of photovoltaic panels was shown to significantly accelerate fire growth. Once openings formed, the compartment fire transitioned into a more intense phase characterised by increased oxygen supply, higher heat release rates and elevated peak temperatures.
Overall, the study concludes that fire performance in photovoltaic facades is governed by a combination of glass type, panel strength and the presence of combustible encapsulation materials. These factors must be carefully considered in façade engineering, particularly for high rise buildings where fire spread risks are amplified.
Among the tested configurations, double glazed photovoltaic panels using tempered glass delivered the strongest performance, maintaining structural integrity for longer and reducing the likelihood of rapid-fire escalation.
As BIPV adoption accelerates across global construction markets, including emerging economies, the findings highlight the need to integrate fire safety considerations into design standards and regulatory frameworks to ensure that clean energy solutions do not introduce unintended risks.
Link to the full paper HERE
Author: Bryan Groenendaal
