Installing solar panels on the facades of buildings is a rising trend, especially in sustainable architecture projects. But how does that affect the risk of fire? Norway has studied it in depth.
The context. Solar panels integrated into the façade of buildings are called BIPV (Building Integrated Photovoltaics) and fulfill a dual function: generating energy and acting as a covering or part of the building envelope, the physical separator between the conditioned and unconditioned environment of a construction. .
A Norwegian research group has been studying how fire could spread in buildings with integrated photovoltaic facades. Researchers have discovered that the distance between the panels and the wall, as well as the presence of combustible materials in the wall cavity, are key to the fire risk of BIPVs.
The findings. “Photovoltaic modules contain polymers that can ignite,” researcher Reidar Stølen told pv magazine. “The rate at which this occurs and the amount of combustible materials contributing to the fire depend on the size of the ignition source, the distance between the building and the module, and whether the module has glass on both sides or just the front. “.
The study is signed by RISE Fire Research AS and the Fire Research and Innovation Center of Norway, as well as by their colleagues at the Danish Institute of Fire Technology.
The method. Researchers evaluated what factors increase the risk of ignition, how the fire spreads vertically along the façade, and whether exposure to heat from the building and neighboring buildings contributes to the fire.
To answer these questions, scientists contacted suppliers, owners and researchers working with these systems. They then conducted 25 experiments with solar panels.
The key. The three factors that contribute to the spread of fires on photovoltaic facades are the distance between the wall and the modules, the presence of photovoltaic panels constructed with glass on one or both sides, and the presence of other combustible materials in the wall cavity.
Experiments with monofacial glass panels and a smaller distance (6 cm) produced the most intense fires. But the crucial factor, according to the results of the experiments, is the distance. As the distance increased, the modules tolerated more heat from the initial fire and released less heat when ignited. Increasing the distance by 4-5 cm has the same effect as changing monofacial glass panels to bifacial ones.
Important. In Europe, all buildings are subject to the EN 13501 standard, which classifies construction materials by their reaction to fire and defines the standard procedures to be followed in their construction. However, a specific study with different types of photovoltaic installations is an important precedent to not compromise the safety of sustainable architecture.
“PV modules can be difficult to classify, as testing methods are not tailored to the unique properties of each PV installation,” the researchers noted.
Imagen | RISE
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