A device has been engineered that combines solar energy and ambient water vapor to produce an impressive daily average of 250 liters of hydrogen. Researchers from Katholieke Universiteit Leuven in Belgium The panel generates a record 250 liters (66 gal) of hydrogen per day and could be used to economically provide local electricity and heating. Source: Tom Bosserezestimate that an array of 20 such panels, paired with an underground pressurized tank, could economically provide all of a household's electricity and heating needs.

The 1.6 m² solar panel directly converts 15% of incident solar radiation into hydrogen. Conventional solar panels boast solar-to-electricity conversion efficiencies in the 18% to 20% range, but if the power produced is then applied to the electrolysis process for hydrogen evolution, overall efficiency declines.

Hydrogen is often produced from fossil fuel sources and can be expensive to produce and store. The new system seeks to eliminate these concerns by combining high conversion efficiency with a small-scale system designed to work at the local scale.

A prototype system will be field tested at a residence in the rural Belgian town of Oud-Heverlee. The hydrogen gas produced in summer can be stored in an underground pressure vessel of about 4 m³ capacity until winter.