Press Releases

About 30 percent of the energy consumption in Germany is used for space heating and warm water. Facades which function as a “thermal wall” can help bring on the transformation of our heating system, yet they have been given little attention up to now. In the ArKol project, a research consortium led by the Fraunhofer Institute for Solar Energy Systems ISE has developed two novel solar thermal façade collectors: a solar thermal strip collector and a solar thermal jalousie. As an integral part of the façade, both elements offer an architecturally pleasing experience.

Commissioned by the renewable energy developer BayWa r.e., the Fraunhofer Institute of Solar Energy Systems ISE investigated the technical potential of floating photovoltaics (FPV) on pit lakes in former lignite mines in Germany. Such FPV plants that basically float on man-made lakes can help to alleviate the competition for land use and help expand PV capacity in Germany. Floating PV technology has several advantages over ground-mounted systems; for instance, greater power production due to the cooling effect of water or higher efficiency of land use. The study estimates a potential PV capacity of 56 GWp for installations on pit lakes in former lignite mines in Germany. After subtracting the estimated area use for recreational activities, tourism, nature and land conservation on pit lakes, there remains an economical potential of 2.74 GWp.

Agrophotovoltaics (APV) allows for the dual harvesting of crops and photovoltaic electricity on the same piece of land, providing sustainable solutions under consideration of soil protection and water conservation. The first international conference on APV systems AgriVoltaics2020 will take place in Perpignan, France from August 26-28, 2020 under the motto “Launching Agrivoltaics World Wide.” The conference is organized by the French National Institute for Agricultural Research (INRA) as well as the Fraunhofer Institute for Solar Energy Systems ISE and the PSE Conferences & Consulting GmbH in Freiburg.

The use of environmental energy to supply heating results in less carbon dioxide emissions. Also the emissions from the electricity generation are steadily decreasing. Therefore, heat pumps are a key heating technology for the future. On the other hand, heat pumps still primarily use refrigerants that are harmful to the environment. Now researchers at Fraunhofer ISE, however, have developed a climate-friendly alternative, which uses propane, a natural gas. The greenhouse gas potential is about 500 times less than conventional refrigerants and thus extremely low. Another advantage is that the new brine-to-water prototype requires only one fourth of the refrigerant compared to conventional heat pumps available on the market at the same power. A propane heat pump based on this development would be the first-of-a-kind in Germany that is permitted in interior spaces of residential buildings without implementing additional safety measures. This new technology shall now be improved upon. For the heat pump industry, new refrigerants are especially important: As of January 1, 2020 first bans on harmful refrigerants take effect in the European Union.

From industry-driven solar cells with efficiency values of more than 22 percent to effective new metallization processes for contacting solar cells — the Photovoltaic Technology Evaluation Center (PV-TEC) at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg has enjoyed numerous technological successes. The research factory, which was rebuilt and significantly expanded in 2018, is the largest R&D center for crystalline silicon solar cells in Europe.

Meeting Germany’s climate protection targets will require a significant expansion of photovoltaics. Depending on the scenario, up to 500 gigawatts of installed PV power output could be needed by 2050. To avoid land-use conflicts and public resistance to this massive expansion, minimizing the additional space occupied by solar modules and seeking out potential synergies is crucial. From September 9 to 13, the Fraunhofer Institute for Solar Energy Systems ISE will be at the EU PVSEC in Marseille (booth F 5) to introduce ideas and technologies for the successful integration of photovoltaics into the built environment.

Together with their project partners, scientists at the Photovoltaic Technology Evaluation Center PV-TEC at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg have succeeded in improving the traditional screen printing process for the fine-line metallization of silicon solar cells. Using specially developed fine-line screens, the project team was able to create contact fingers with a width of merely 19 µm and a height of 18 µm in a single printing step. This means that up to 30 percent less silver is needed, which in turn leads to a significant reduction in manufacturing costs.

The demand for electric vehicles is increasing worldwide. To extend the driving range, the Fraunhofer Institute for Solar Energy Systems ISE has developed a solar car roof with highly efficient solar cells. The roof can be coated in any color, with the solar cells integrated invisibly into the preformed solar roof. The photovoltaic cells with a nominal power of about 210 W/m² provide sustainable electricity for a daily mileage of about 10 km with an average electric car on a sunny day. Calculated over one year, the driving range can be extended by about 10 percent. At the joint booth of the Fraunhofer-Gesellschaft (Hall 4.1, Booth C 12) at the Frankfurt Motor Show IAA, Fraunhofer ISE presents two solar car roofs in different colors.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have once again succeeded in raising the efficiency value of monolithic triple-junction solar cells made of silicon and III-V semiconductor materials. Using a combination of multiple absorber materials, these multi-junction photovoltaic cells exploit the energy from the solar spectrum significantly better than conventional silicon solar cells. The world record for a monolithic multi-junction solar cell manufactured by wafer bonding has been increased to 34.1% and an efficiency record of 24.3% achieved for a solar cell with the III-V semiconductor layers deposited directly on the silicon.

On July 4, 2019, the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg officially inaugurates its new Center for Power Electronics and Sustainable Grids. With a propriety connection to the 110 kV high-voltage grid and 40 MVA transformer, the new center offers a worldwide unique research infrastructure which enables it to meet the growing demands on power electronics, a key technology for the energy system transformation.