To BIPV or to BAPV - that is the question!

Did you know that the first net-zero building in Brussels had a fire in its BIPV installation recently?!

As urban areas strive toward sustainability, building-integrated photovoltaics (BIPV) and building-applied photovoltaics (BAPV) are emerging as popular technologies to help reduce reliance on traditional energy sources.

Both systems use solar energy to power buildings, but they differ significantly in design and application. BIPV, as the name suggests, integrates solar panels directly into the structure of a building, replacing traditional building materials on roofs, façades, or windows. This integration enables BIPV to fulfil both architectural and energy functions, merging energy production with aesthetic design.

BAPV, on the other hand, involves attaching solar panels to a building without integrating them into its core structural elements, making it a simpler, add-on solution for renewable energy generation.

However, in addition to many benefits, each type of design brings critical fire safety concerns that must be carefully managed. BIPV and BAPV present different fire risks due to their varied integration levels and structural impacts on the building. BIPV’s direct incorporation into building façades and roofs can create pathways for fire spread, posing unique safety challenges compared to BAPV, where solar panels have less direct interaction with the building’s primary structure. With the reported incidence of 29 fires per year per gigawatt installed for BAPV installations [1], fire safety experts question if BIPV installations may face even higher risks due to their design complexities, integrated nature, and electrical requirements.

This newsletter explores the critical differences in fire safety between BIPV and BAPV, addressing key questions that the fire safety community must consider. We examine the potential fire risks associated with BIPV installations and whether BIPV’s fire behaviour resembles façade fires more closely than rooftop fires. We explore whether installation, fire dynamics, and cavity geometry contribute to BIPV fire risks. Furthermore, we will look at the current state of fire safety research for BIPV, along with testing standards, regulatory requirements, and the technological distinctions that define each system.