Custom-colored modules can boost public approval of solar panels on buildings

25 Nov 2024

Fraunhofer ISE and University of Freiburg conduct joint study on social acceptance of building-integrated PV.

Historic building in Eppingen with a red roof-integrated PV system.

While solar power is undoubtedly a cleaner, greener alternative to fossil fuel-generated electricity, not everybody wishes to see cherished buildings covered with PV panels. But as the technology is developed, the possibility of different panel colors is leading to designs that camouflage arrays of solar cells.

To investigate how this might change public opinion on such developments, the Institute of Psychology at the University of Freiburg and the Fraunhofer Institute for Solar Energy Systems (ISE) conducted a joint study on the social acceptance of building-integrated photovoltaics (BIPV).

The conclusions showed that the acceptance of integrated photovoltaics in urban areas is generally very high and that PV on modern buildings is viewed more positively than on historic buildings. The study also showed, however, that when PV modules are colored to match a building’s roof or façade so that they are practically invisible, then the social acceptance is increased to the point where no difference is detected between the different building types.

The study, which was conducted as part of the livMatS Cluster of Excellence at the University of Freiburg, analyzed two surveys: an online survey based on photos; and a survey in presence where differently colored PV modules with MorphoColor® technology were shown.

“An important finding of the study is that the social acceptance of PV systems depends on the type of building and visual impression. These two factors weigh much more heavily than personal variables such as personal values, political attitudes or environmental concerns,” commented Angela Zhou, master’s student at the University of Freiburg and lead author of the study.

“The study provides initial insights into the social acceptance of PV systems on and around buildings,” added Andreas Wessels, PhD student at ISE and co-author of the study. “It confirms that the acceptance of PV systems can actually be increased through good visual integration with colored modules, especially for historic buildings,” he said.

It can be concluded from the study that for existing buildings it makes more sense to select colored PV modules that blend homogeneously into a building’s appearance rather than using PV as an architectural detail. Therefore, stated the ISE announcement, “it is important to offer a wide range of aesthetically different PV modules to match the different existing buildings. Building-integrated photovoltaics on new buildings was not examined in the study, so this restriction need not apply here.”

Dr. Robin Lang was honored at PVSEC-35.

ISE calculates that 75 percent of installed PV is located on buildings. The market for photovoltaics on buildings is growing continuously and holds great potential. “Around 400 gigawatts-peak of installed PV power will be required by 2045 for the energy transition in Germany to succeed. With a technical potential of around 1000 gigawatts-peak, photovoltaics on buildings can make a significant contribution to the decarbonization of the building sector and built infrastructure – without taking up additional land area,” concluded the ISE statement.

ISE scientist wins Best Oral Presentation Award at Tokyo solar conference

ISE scientist Dr. Robin Lang was distinguished with the Best Oral Presentation Award at the 35th International Photovoltaic Science and Engineering Conference (PVSEC-35), held last week in Tokyo, Japan, for his outstanding scientific presentation in the field of III-V solar cells. In his presentation, the researcher from the Fraunhofer ISE in Freiburg presented his research results and provided a detailed loss analysis of the production of a III-V multi-junction solar cell.

Dr. Lang’s presentation was entitled “Development of Wafer-Bonded III-V Concentrator Solar Cells with Six Junctions”. In his talk he explained the complex manufacturing process of a six-junction solar cell grown using metal organic vapor phase epitaxy (MOVPE) and presented a detailed loss analysis. Thanks to improvements in the cell structure, the cell voltage could recently be increased by 140 millivolts.

“Thanks to the improved cell structure, the multi-junction solar cells produced in this way almost reach the efficiency of the current world's best solar cell,” said Prof. Dr. Stefan Glunz, Head of the Photovoltaics Division at ISE.