© Fraunhofer ISE / Photo: Sophia Baechle | Najwa Abdel Latif, project manager at Fraunhofer ISE, inspects the interconnected solar cells on Fraunhofer ISE’s shingle-matrix stringer.
The American company Source Energy and the Fraunhofer Institute for Solar Energy Systems ISE have jointly developed a new product line for space satellites based on silicon solar cells.
The solar arrays are using a special interconnection technology. Combined with inexpensive silicon solar cells, this enables modules at much lower costs compared to standard III-V technology that currently dominates the space sector. The automated production process, utilizing the M10 Solar Equipment GmbH’s Shingle-Matrix Stringer, allows Source Energy to delivery their products in less than six months from the time of order.
Solar cells based on III-V materials are the current standard for power generation in space. However, their high cost and limited availability are major constraints for commercial missions, particularly Low Earth Orbit (LEO) satellites. “Together with Source Energy, we have therefore developed silicon-based solar modules for space applications, similar to those already in successful and cost-effective use on Earth,” explains Dr. Achim Kraft, head of the PV Module Technologies department at Fraunhofer ISE.
The resulting solar modules are compact and lightweight: 64 grams and 629 square centimetres, (321 by 209 millimetres). The average power output of the prototypes was 15.6 watts – with modules achieving 16.1 watts – and an average active area efficiency of 18.8 percent (AM0 at 25 °C). At 252 watts per kilogram, the module’s specific power is competitive with other silicon modules in its class.
The silicon solar cells are interconnected using shingle-matrix technology, where individual solar cells are cut into strips and arranged with certain overlap and spacing relative to one another, like brickwork. An electrically conductive adhesive bonds the solar cells together.
The machine manufacturer M10 Solar Equipment GmbH has developed an industrial stringer for shingle-matrix technology. Following a successful prototyping phase at the Module-TEC facility of the Fraunhofer ISE in Freiburg, Source Energy installed the system at its own manufacturing facility in Colorado in June 2026. “As the heart of our production, it enables us to manufacture PV panels for less than $5 per watt,” says Bryan Mazor, CTO at Source Energy. “The automated manufacturing process not only makes us more cost-effective but also significantly faster than is currently the case with III-V PV products for space.”
“Three features make the shingle-matrix interconnection perfect for space,” explains Najwa Abdel Latif, project manager at Fraunhofer ISE. “Resilience to localized physical damage from impacts by small objects in space, flexibility in layout, and tolerance to extreme temperature differences.”
If the solar panel is damaged – for example, by a small meteorite or space debris – the matrix arrangement of the solar cells allows the current to simply flow around the damaged area. At the same time, the rows and columns of solar cells in the layout can be flexibly adjusted depending on the satellite’s voltage and current requirements.
“The shingle-matrix technology is compatible with wafer-based solar cells featuring front and back contacts, such as PERC or silicon heterojunction, without having to adapt the production line,” says Abdel Latif. “Thanks to the low-temperature interconnection process, there will be no issues with the future technology of perovskite silicon tandem either.”
Once on a mission, high resistance to extreme temperature fluctuations is crucial for the solar panels. The research team at Fraunhofer ISE therefore chose product material that can successfully maintain their performance under these conditions. Source Energy subjected the newly developed module to comprehensive space qualification testing and confirmed that it falls within the 25 percent qualification threshold for space applications. Specifically, after seven years of operation in space, the module is expected to retain 76 percent of its original power output.
Fraunhofer ISE 2026
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