Photovoltaics are usually applied to the roofs of buildings, but a far greater surface area could be exploited to harness energy from the sun. Scientists from the Fraunhofer Centre for Silicon Photovoltaics (CSP) in Halle have collaborated with architects from the Leipzig University of Applied Sciences (HTWK) to develop a solar façade which is capable of out-performing previous building-integrated photovoltaic solutions. It comes down to the fact that PV cells can be tilted to capture more sunlight.

The ‘Solar Shell’ prototype was unveiled in March 2020: an abstracted construction of aluminium-composite panels into which nine solar modules were embedded. "The photovoltaic elements integrated into this façade provide up to 50 percent more solar energy than solar modules mounted planar on building walls," explains Sebastian Schindler, project manager at the Fraunhofer CSP, to PV Magazine. "And, the façade also looks good."

The CSP has also been working on other solutions, such as integrating PVs into specially-evolved ‘carbon concrete’. For this project, they worked with the HTWK Leipzig and the Technical University Dresden on three different techniques: casting solar modules directly into the concrete, gluing or laminating them to the slabs and also fastening the modules to the slabs with snap fasteners and other methods in order to facilitate maintenance and repairs. "We were able to show that all three fastening options are technically feasible," says Schindler.

The concepts will be worked into market-ready solutions in the follow-up project ‘SOLARcon: Concrete Facades 2.0’, which was launched in November 2019. More research needs to be conducted into how they behave under different weather conditions and react to aging tests. The potential for BIPV solutions is substantial, however: from this year, Germany requires all new-builds to reach the "lowest energy house" building standard.