Press Releases 2016

Research and industry invest lots of know-how in improving solar cell efficiency. In order that PV modules benefit from the advances in cell efficiency, the cell-to-module integration process must be performed reliably with low losses. With this in mind, the photovoltaic module group at Fraunhofer ISE developed the software SmartCalc.CTM, which enables manufacturers of PV modules and materials to optimize the assembly and material combination in a PV module, before fabricating a prototype.

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs. Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power electronic systems in aviation applications more efficient.

On November 11, 2016 at the Konzerthaus in Freiburg, the Fraunhofer Institute for Solar Energy Systems ISE honored Prof. Eicke R. Weber’s achievements at a scientific symposium on the global energy transformation. Having reached retirement age, Prof. Weber will step down from his position as Institute Director at the end of the year. Weber gave the German solar research a voice that is observed worldwide. With great enthusiasm he supported the energy transformation on both the scientific and political arenas. At the Institute, he organized the structure and business areas to optimally meet the demands of the energy transformation. From 2006 to 2016, he was able to double the number of employees to 1100 today. Over the same time period, the operating budget, based primarily on self-acquired projects, grew from ca. 25 million euros up to 73 million euros (2015).

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with the Austrian company EV Group (EVG) have successfully manufactured a silicon-based multi-junction solar cell with two contacts and an efficiency exceeding the theoretical limit of silicon solar cells. For this achievement, the researchers used a “direct wafer bonding” process to transfer a few micrometers of III-V semiconductor material to silicon, a well-known process in the microelectronics industry. After plasma activation, the subcell surfaces are bonded together in vacuum by applying pressure. The atoms on the surface of the III-V subcell form bonds with the silicon atoms, creating a monolithic device. The efficiency achieved by the researchers presents a firsttime result for this type of fully integrated silicon-based multi-junction solar cell. The complexity of its inner structure is not evident from its outer appearance: the cell has a simple front and rear contact just as a conventional silicon solar cell and therefore can be integrated into photovoltaic modules in the same manner.

Freiburg/Mumbai, October 20, 2016. The Canopus Foundation and the Fraunhofer Institute for Solar Energy Systems ISE, who collaboratively organized the 2nd »Solar for All« Contest for Innovative Community Solar Electrification Solutions 2016, yesterday announced the winners. For the past nine months, »Solar for All« was running the Contest to find the best innovations in providing rural low income communities in remote regions without access to energy with affordable and clean solutions, focusing on scalability, technical standards and a developed market approach. The Award Ceremony took place in Mumbai and was hosted by Intersolar India.

In 1981, an article by Prof. Adolf Goetzberger titled "Potatoes under the Collector" was published in the German magazine “Sonnenenergie”. The article proposed a particularly favorable setup for solar energy systems in combination with agricultural land use. After smoldering on the backburner for a couple of years, the concept of agrophotovoltaics (APV), that is, the dual usage of land for crop and electricity production, was again taken up by researchers at Fraunhofer ISE in 2011. Now the scientists at Fraunhofer ISE together with their partners in the project "APV-Resola" are reaping the benefits from Goetzberger’s original article: On September 18, 2016 an operating APV pilot system – the largest research project of its kind in Germany – was inaugurated on location at Lake Constance. On this occasion the project was also presented with a prize from the "Germany – Land of Ideas" initiative.

In 2016 more than 35 percent of our electricity will come from renewable energy sources. Increasing the flexibility of the energy system through storage systems is therefore being addressed by science and industry at all levels. One focus is the development of storage solutions based on lithium-ion batteries for private households. These batteries are especially efficient and durable. To date, however, adequate standards and testing procedures do not exist for this technology. The Fraunhofer Institute for Solar Energy Systems ISE is now working on two research projects which address the aspects related to the acceptance and dissemination of the technology. The German Federal Ministry for Economic Affairs and Energy (BMWi) provides funding for both projects.

More than one billion people still have no reliable access to electricity, particularly in rural areas in developing countries. The cost for photovoltaic (PV) technology has been dropping continuously in the past years, making solar electricity an even more viable solution for these regions. Reliable PV systems for community electrification that are well adapted and scalable are required.