New solar reactor makes green hydrogen cheaper than electrolysis

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia has developed a novel "beam-down" solar reactor that uses concentrated sunlight to produce green hydrogen fuel more cost-effectively than traditional electrolysis. Unlike conventional solar thermal systems that focus sunlight atop a tower, this design uses heliostats to reflect sunlight downward onto a ground-level platform, where intense heat drives a thermochemical reaction to split water into hydrogen and oxygen. This approach leverages doped ceria, a modified mineral that facilitates a two-step oxygen exchange process at reduced temperatures, enabling efficient and reusable hydrogen production. This innovation addresses the challenge of decarbonizing hard-to-electrify sectors such as heavy industry and transport, which currently rely heavily on fuel-based energy sources. While electrolysis remains energy-intensive and costly, CSIRO’s beam-down reactor demonstrates strong reactivity under moderate conditions and has the potential to match electrolysis in both performance and cost with further refinement. The ground-level receiver design also offers greater flexibility for high-temperature