A record year for our living lab for building-integrated PV
© BAIP/HZB
In 2025, our solar facade in Berlin-Adlershof generated more electricity than in any of the previous four years of operation.
With about 32 MWh, the solar facade of our BIPV living laboratory produced enough electricity to power more than 12 average four-person households. Thanks to the energy-intensive research landscape at the Helmholtz-Zentrum Berlin, we can also consume all of the electricity generated on site at any time.
Even after five years of operation, our building-integrated solar modules show no measurable degradation. Differences in annual energy yield can so far be attributed exclusively to weather-related fluctuations. According to the German Weather Service, the duration of sunshine in 2025 was around 1,900 hours nationwide. In addition, the year was comparatively low in precipitation, which, together with the high duration of sunshine, explains the high solar yield.
However, we were particularly surprised by December: exceptionally good PV weather led to yields more than twice as high as in the previous year! Especially in spring, autumn and winter, the sun is more favourable for the solar facade, so we regularly observe higher yield peaks than in the summer months.
We are excited to see how this year will turn out.
- Green hydrogen with PEC electrolysers: New insights into transport processesOne method of storing solar energy is to use PEC electrolysers to produce hydrogen. However, scaling up this technology remains challenging. Now, a team at the HZB Institute for Solar Fuels has used 2D fluorescence imaging and particle velocimetry to observe the movement of ions and dissolved gases within the electrolyte during electrolysis. These new insights may prove useful in the development of larger PEC electrolysers.
- New contact material boosts the efficiency of perovskite solar cellsA newly developed material for the electron contact improves the efficiency of single perovskite solar cells and perovskite/silicon tandem solar cells. The new material is based on a carborane molecule. It offers several advantages over the standard material C60, as shown by the study led by Steve Albrecht’s team. The new material has since been patented and is already commercially available.
- BESSY II: New sample environment allows glimpse into thermocatalytic processesA novel measurement cell allows, for the first time, soft and hard X-ray investigations under high pressures of up to 20 bar and temperatures of up to 400°C. This provides new insights into thermocatalytic processes, such as the Fischer-Tropsch synthesis for producing synthetic fuels. The development of the measurement cell is considered a significant achievement within the Care-O-Sene project.