Not yet widespread: Building-integrated photovoltaics
An increasing number of solar systems have been installed in the city of Neuchâtel over the past years: four only in 2012, 68 by 2015. But building-integrated photovoltaics still lead a niche existence: of the 202 systems installed by the end of 2015, only three were integrated into buildings. To elucidate the reasons for this situation, the researchers selected twelve representative buildings which differ in various respects: for example, buildings in different construction phases, free-standing buildings as opposed to buildings embedded in a line of houses, or presenting different types of roofs (flat or inclined). The scientists then interviewed the architects and owners (pension funds, real estate funds, foundations and state authorities) of these buildings.
Their conclusions: there are many reasons why building-integrated photovoltaics are rarely installed. For architects, the following factors are decisive:
- Limited knowledge among both clients and architects regarding building-integrated solar energy.
- Lack of social pressure, also from politicians.
- High costs for building integration which deter investors.
The architects also mentioned a current lack of experience with building-integrated photovoltaics that complicates planning. The owners agree with the above points, but also state that the administrative procedures for the planning and approval of projects are very cumbersome. However, the discussions also pointed to the potential of the technology: both architects and owners are convinced of its efficiency. Despite the fact that the choice of shapes, colours, sizes and textures seems satisfactory, architects hope for further diversification.
The interviews showed that successfully completed projects are essential, since they clearly demonstrate the feasibility of the technology. According to the researchers, this in turn means that a growing number of individuals will in future consider integrating these systems into their plans. It is also helpful to call in solar energy specialists who can advise and convince architects and provide the relevant information regarding current developments on the market. The majority of the interviewees, i.e. 81 %, think that the government should subsidise building-integrated photovoltaics to make these systems affordable for owners.
The scientists point out that building-integrated solar cells are a good option not only for new buildings, but also in the context of pending renovations. On the other hand, the premature replacement of an intact and contemporary building envelope is not a sustainable option.