SunHydrogen, Inc., a developer of breakthrough technology for producing renewable hydrogen using sunlight and water, has announced strong test results from a recent visit to Japan. Collaborating with consultants Professor Kazunari Domen, Dr. Hiroshi Nishiyama, and Dr. Taro Yamada at the University of Tokyo, and visiting the Honda R&D facility in Tochigi, SunHydrogen has made significant strides in large-area solar-to-hydrogen efficiency.
At Professor Domen’s laboratory at the University of Tokyo, SunHydrogen conducted large-area solar testing of its 1200cm² hydrogen modules, manufactured in partnership with CTF Solar. These modules formed part of the company’s recent 1m² demonstration system. The 1200cm² modules achieved an active-area solar-to-hydrogen efficiency of 9%. This is a record high efficiency reported for a hydrogen module of this size.
Previously, SunHydrogen had validated an efficiency exceeding 10% in its smaller 100cm² hydrogen modules, tested at Honda R&D. The current results demonstrate that even with a tenfold scale-up in size, the company has maintained near the 10% efficiency threshold. This achievement underscores the viability of their technology for larger-scale applications. Furthermore, the modules were tested across a broad temperature range, from 5°C to 40°C, and maintained stable efficiency throughout. A state-of-the-art LED solar simulator, capable of simulating the solar spectrum over a large area, was used for these tests.
Following the lab testing at the University of Tokyo, the SunHydrogen team visited their joint development partners at Honda R&D. They observed on-sun rooftop testing of SunHydrogen’s 100cm² hydrogen modules. Honda’s innovative housing unit design enables hydrogen and oxygen separation without membranes – a novel approach. Honda will soon begin testing the larger 1200cm² modules under similar real-world, on-sun conditions. SunHydrogen anticipates using the performance data from these extended tests to further refine its module design.
This visit to Japan provided valuable insights and key validation for SunHydrogen’s technology, both in controlled laboratory settings and real-world outdoor environments. The University of Tokyo’s solar simulator enabled the most comprehensive and precise efficiency testing of the large-area modules to date. Honda’s membrane-free separation approach represents a significant milestone in real-world implementation of the technology.