Key facts
- A new prototype system directly converts sunlight into hydrogen fuel with 31.3% efficiency.
- The system combines advanced solar cells with proton exchange membrane electrolyzer cells.
- This direct conversion method is more efficient than generating electricity first.
- The technology utilizes III-V solar cells, known for their high performance and durability.
- Green hydrogen is seen as a critical clean alternative for hard-to-abate industrial sectors.
- The development is in its early stages, and a spin-off company is seeking investors.
Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) in Germany have developed a novel prototype system that directly converts sunlight into hydrogen fuel with a record efficiency of 31.3 percent. This breakthrough addresses a key challenge in the green hydrogen sector by bypassing the traditional two-step process of generating electricity from solar panels and then using that electricity to produce hydrogen.
The new system utilizes highly efficient III-V solar cells, commonly found in spacecraft due to their performance and durability, integrated with proton exchange membrane electrolyzer cells. This direct conversion method significantly improves efficiency, as noted by Dr. Frank Dimroth, who stated, "Our new record shows that hydrogen can be produced very efficiently directly from sunlight."
Green hydrogen is considered a vital clean energy source for industries that are difficult to decarbonize, such as steelmaking and shipping, as its combustion produces only water vapor. However, the production of green hydrogen has faced significant hurdles, including high costs and inefficiencies. A study published in Nature Energy indicated that in 2023, only 7% of planned green hydrogen capacity was completed on schedule, highlighting an "implementation gap."
An International Renewable Energy Agency (IRENA) report also cautioned against the "indiscriminate use of hydrogen," suggesting that renewable energy might be better utilized directly in other applications rather than being converted into hydrogen, due to efficiency losses. The Fraunhofer ISE's direct solar-to-hydrogen approach aims to overcome this by making the process more efficient and potentially commercially scalable.
Despite the promising results, the technology is still in its early stages. Dr. Dimroth mentioned that "Development is still in its early stages, and it's hard to say how quickly we'll be able to achieve competitive systems." To advance the concept, the researchers are seeking investors for a planned spin-off company, Clearsun Energy. The current global energy crisis has reportedly revitalized investor interest in green hydrogen research, potentially aiding in securing the necessary funding.