Solar Panel Splits Water to Produce Hydrogen

A research team in Belgium says its prototype panel can produce 250 liters of hydrogen gas per day

Solar panels are multiplying on rooftops and in gardens worldwide as communities clamor for renewable electricity. But engineers in Belgium say the panels could do more than keep the lights on—they could also produce hydrogen gas on site, allowing families to heat their homes without expanding their carbon footprints.

A team at Katholieke Universiteit Leuven, or KU Leuven, says it has developed a solar panel that converts sunlight directly into hydrogen using moisture in the air. The prototype takes the water vapor and splits it into hydrogen and oxygen molecules. If it scales successfully, the technology could help address a major challenge facing the hydrogen economy.

Hydrogen, unlike fossil fuels, doesn’t produce greenhouse gas emissions or air pollution when used in fuel-cell-powered vehicles or buildings. Yet nearly all hydrogen produced today is made using an industrial process that involves natural gas, and this ultimately pumps more emissions into the atmosphere.

A small but growing number of facilities are producing “green” hydrogen using electrolysis, which splits water molecules using electricity—ideally from renewable sources such as wind and solar. Other researchers, including the team in Belgium, are developing what’s called direct solar water-splitting technologies. These use chemical and biological components to split water directly on the solar panel, forgoing the need for large, expensive electrolysis plants.