Hanwha Qcells to supply tandem cells for US space solar power demonstration on the moon

Hanwha Solutions' Qcells division — known as Hanwha Qcells — will take part in a space solar power demonstration that aims to send its next-generation perovskite-based tandem cells to the moon.

Hanwha Qcells said Monday that its German subsidiary has joined the Space Science and Technology Experiment Facility (SSTEF-1) project as a partner alongside Georgia Institute of Technology, agreeing to supply tandem cell samples. The tandem cell achieves an efficiency of 44 percent — about 1.5 times higher than the theoretical efficiency ceiling of 29 percent for conventional silicon cells.

The SSTEF program is a space technology demonstration initiative funded by NASA and led by US-based Aegis Aerospace. The Georgia Tech Research Institute (GTRI), a nonprofit applied research arm of Georgia Tech, selected Hanwha Qcells' tandem cells as the demonstration product for a mission to evaluate solar cell performance in the space environment.

GTRI plans to install Hanwha Qcells' tandem cell samples on the surface of a lunar lander and expose them to space conditions to gather performance data. Hanwha Qcells said it will use that data to shape its research and development direction toward securing the most reliable space solar power technology.

The tandem cells supplied for the demonstration were developed using proprietary technology at Hanwha Qcells' R&D center in Thalheim, Germany. The cells can achieve high efficiency comparable to existing space-grade cells while reducing weight relative to the same installed capacity. Hanwha Qcells is targeting 2029 for the commercialization of ground-use tandem products and plans to extend tandem technology into the space solar power sector.

Hanwha Qcells has also obtained International Electrotechnical Commission (IEC) certification for a ground-use perovskite-based tandem module it developed and manufactured in-house — a world first for a perovskite-based tandem module.

In December 2024, Hanwha Qcells recorded a then-world-record efficiency of 28.6 percent on a large-area tandem cell — full-size M10 format — scalable to commercial mass production, independently verified by the CalLab at Germany's Fraunhofer Institute for Solar Energy Systems. The result demonstrated the potential to generate more electricity from the same surface area.

The latest achievement is significant because it translates that technology into a commercial product — a tandem module — and clears the long-term reliability evaluation required for international certification standards. The tandem module passed all categories of solar module reliability assessment under IEC and UL international standards, as evaluated by global solar certification body TÜV Rheinland. Those assessment categories reproduce the extreme conditions a module would face in real-world environments to verify durability and safety.

Hanwha Qcells is also running parallel outdoor performance validation of its tandem modules. Modules operating at the Thalheim R&D center and at a third-party demonstration facility — for approximately one year and six months, respectively — have maintained stable power generation performance to date.

"Building on the technological capabilities and market competitiveness we have accumulated through our solar manufacturing business, Hanwha Qcells will advance into a global renewable energy solutions company that opens the era of space solar power," Park Seung-deok, chief executive of Hanwha Qcells, said. "This project will be an important turning point in extending the possibilities of sustainable energy all the way to space."