Press Releases

Setting up a manufacturing facility or developing new technologies – NEXUS GreenTech, the new spin-off of the Fraunhofer Institute for Solar Energy Systems ISE, supports manufacturers of wafers, solar cells, and PV modules with issues related to product development and factory planning. The founders, Dr. Jochen Rentsch, Dr. Sebastian Nold, and Dr. Nico Wöhrle previously spent many years researching PV technologies, associated production processes, and quality assurance, and all three were most recently part of the PV Technology Transfer unit at Fraunhofer ISE. The spin-off, founded at the end of March, is headquartered in Freiburg, Germany.

Steel production generates large quantities of so-called “furnace gases,” which are rich in hydrogen and carbon oxides. In the Carbon2Chem® project, partners from industry and research are investigating the material utilization of these gases. The Fraunhofer Institute for Solar Energy Systems ISE demonstrated the conversion of purified steel mill exhaust gases into methanol in a mini-plant over a period of more than 5,000 hours. Modeling the process in a digital twin of the plant helped researchers optimize it and significantly increase productivity. The simulation platform developed can now also be used for other applications, such as the production of jet fuels.

Charging infrastructure for battery-powered heavy-duty and passenger transport is crucial for a successful transportation transition. The trend here is toward higher charging power and, consequently, higher charging currents and voltages. The collaborative project “HV-MELA-BAT” therefore developed the power electronic converters required for XXL charging, as well as a con-tact system for high currents and voltages. Thanks to a high switching frequency, the isolated DC/DC converter achieves a volumetric power density of 9 kW/l while maintaining a record-breaking efficiency of 99.26 percent. A buffer storage unit was integrated to ensure full charging power even at power-limited grid connection points.

A consortium of scientists from the Fraunhofer Institute for Solar Energy Systems ISE and Smart Battery Solutions GmbH succeeded in replacing the steel connectors used to interconnect battery cells with copper during resistance projection welding. In doing so, the team demonstrated something that had long been considered impossible in the battery industry: Until now, battery manufacturers looking to switch to more powerful, copper-interconnected batteries had to replace their projection welding systems with laser welding systems.

Scientists at the Fraunhofer Institute for Solar Energy Systems ISE have succeeded in constructing two tandem photovoltaic modules with record efficiencies. A III-V germanium PV module with an efficiency of 34.2 percent, incorporating solar cells from AZUR SPACE and anti-reflection structures from temicon, thus becomes the most efficient solar module in the world. A III-V silicon PV module achieves an efficiency of 31.3 percent, setting a record in its class, and is based on established, cost-effective silicon technology.

To ensure energy security and achieve its climate protection goals, Germany will import large quantities of hydrogen in the future. Dimethyl ether (DME) is an environmentally friendly, non-toxic, efficient, and economically attrac-tive gas that shows great promise as an energy source for hydrogen and its derivatives. The Fraunhofer Institute for Solar Energy Systems ISE has developed a new, particularly energy-efficient synthesis process for its production, which could become a game changer for DME production and thus for the hydrogen economy. In the international “Power-to-MEDME” project, the entire process chain for large-scale production of methanol and DME in Chile was researched on this basis.

In 2025, the share of renewables in Germany’s net public electricity generation amounted to 55.9 percent, as in the previous year. Wind power took first place as the strongest net electricity producer, followed by photovoltaics, which increased its production by 21 percent in 2025 and overtook lignite for the first time. The share of electricity generation from fossil fuels stagnated in 2025, with the decline in lignite-based electricity generation being offset by rising natural gas consumption. The share of imports in the electricity mix fell in 2025 compared to the previous year. This analysis is based on the energy-charts.info data platform of the Fraunhofer Institute for Solar Energy Systems ISE, which provides interactive graphs on electricity generation for the whole of Europe.

Until 2009, German PV system owners hardly used any of the electricity they generated themselves, as the feed-in tariff for photovoltaic electricity was higher than the price of electricity purchased from the grid. Since this ratio has reversed and sector coupling has expanded the possibilities for use, the economically motivated self-consumption of solar power in Germany has risen sharply. Research scientists at the Fraunhofer Institute for Solar Energy Systems ISE have now developed the first method for quantifying PV self-consumption based on data from the market master data register and transmission system operators. They published their findings in an analysis for the German Federal Environment Agency.

The goal of "Heat Pumps Watch" is to collect, evaluate, and present scientific findings on heat pumps making them easy to understand and useful for different target groups. The spin-off led by scientist Dr. Marek Miara from the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg aims to provide orientation on the topic of heat pumps for professionals, policymakers, and homeowners considering a change in their heating systems. Heat Pumps Watch is a non-profit organization, and its first project is funded by the Climate Neutrality Foundation.

Heat pumps provide efficient and climate-friendly heating also in existing buildings. This is the conclusion of a research project by the Fraunhofer Institute for Solar Energy Systems ISE. Over four years, researchers conducted detailed measurements on 77 heat pumps in single-family to three-family homes. The result: the heat pumps achieved seasonal performance factors ranging from 2.6 to 5.4. The CO2 emissions of the heat pumps, calculated for the first time considering time-variable factors, were 64 percent lower in 2024 compared to those of natural gas heating systems. The research team also conducted long-term sound measurements and investigated how photovoltaic systems can be integrated into heat pump operation. In addition to Fraunhofer ISE, two energy suppliers and nine heat pump manufacturers participated in the project.