Scientists in Germany have developed a breakthrough solar technology that could significantly transform the future of clean energy production. Researchers at the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) have created a new solar module capable of converting 31.3% of incoming sunlight directly into green hydrogen, marking one of the highest efficiencies ever achieved by a direct solar-to-hydrogen system.
The innovation combines Concentrating Photovoltaic (CPV) cells directly with Proton Exchange Membrane (PEM) electrolyser cells, allowing solar energy to split water into hydrogen and oxygen without the need for intermediate electrical conversion. The development is being viewed as a major step towards making commercial-scale green hydrogen production more efficient and economically viable.
Unlike conventional solar-powered hydrogen systems, which require electricity generated by solar panels to pass through multiple conversion stages, the new technology eliminates the need for AC-DC conversion and voltage adjustments. By directly connecting the solar cells with the electrolyser, the system minimises energy losses and significantly improves overall efficiency.
The module uses a Fresnel lens to concentrate sunlight onto highly efficient III-V multi-junction solar cells. These advanced photovoltaic cells generate more than 4 volts of electricity, which is supplied directly to two PEM electrolyser cells. The electrolysers then split water molecules into hydrogen and oxygen, producing green hydrogen using only solar energy.
Researchers tested the prototype under real-world conditions using a compact system with a lens area of approximately 64 square centimetres. During the field trials, the module successfully converted 31.3% of the incoming solar energy into chemical energy stored as hydrogen, making it one of the most efficient direct solar-to-hydrogen systems demonstrated to date.
Dr. Frank Dimroth, Head of the III-V Photovoltaics and Concentrator Technology Department at Fraunhofer ISE, said the record efficiency demonstrates that hydrogen can be produced directly from sunlight in an extremely efficient manner. He described the achievement as an important milestone in advancing next-generation clean energy technologies.
The III-V solar cells used in the project are among the world’s most efficient photovoltaic devices and have long been used in satellites and space missions because of their exceptional performance and durability. Researchers believe that concentrating photovoltaic technology could now make these high-performance cells economically viable for large-scale terrestrial applications.
Green hydrogen is widely regarded as a key fuel for the global energy transition because it produces zero carbon emissions when used. It has applications across steel manufacturing, chemicals, heavy transport, electricity generation and long-duration energy storage. If successfully commercialised, the technology could reduce dependence on fossil fuels while accelerating the adoption of clean energy worldwide.
Although the prototype has achieved record-breaking efficiency, the researchers emphasised that the technology is still in its early stages of development. Fraunhofer ISE is currently seeking investors to support commercialisation and plans to establish a new company, Clearsun Energy, to bring the technology to market. A commercial launch timeline has not yet been announced.
If successfully scaled for industrial use, the breakthrough could pave the way for producing green hydrogen directly from sunlight, offering a cleaner, more sustainable and highly efficient alternative to conventional energy sources.
Disclaimer: This report has been editorially prepared using publicly available information and agency inputs. While every effort has been made to ensure accuracy, unintentional errors or omissions may occur. Readers are encouraged to verify critical information from official sources.
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