Bioscience engineers at KU Leuven have created a solar panel that produces hydrogen gas from moisture in the air. After ten years of development, the panel can now produce 250 liters per day—a world record, according to the researchers. Twenty of these solar panels could provide electricity and heat for one family for an entire winter.
A traditional solar panel converts between 18 to 20% of the solar energy into electricity. If that electric power is used to split the water into hydrogen gas and oxygen, you lose a lot of energy. The KU Leuven bioscience engineers solved this problem by designing a solar panel of 1.6 m² that converts 15% of the sunlight straight into hydrogen gas.
It’s a unique combination of physics and chemistry. In the beginning, the efficiency was only 0.1 per cent, and barely any hydrogen molecules were formed. Today, you see them rising to the surface in bubbles. So that’s ten years of work—always making improvements, detecting problems. That’s how you get results.
—Professor Johan Martens
Twenty of these panels produce enough heat and electricity to get through the winter in a thoroughly insulated house and still have power left. Add another twenty panels, and you can drive an electric car for an entire year.
—KU Leuven researcher Jan Rongé
Today, most hydrogen gas is produced using oil and gas.—Grey hydrogen gas, in other words—not a big win for the climate or the environment. The KU Leuven researchers believe this is about to change.
The solar panel will be under test in Oud-Heverlee, a rural town in Flemish Brabant. The house we visit is well insulated and gets most of its power from solar panels, a solar boiler, and a heat pump. It is not connected to the gas grid. It only uses power from the grid in the winter.
Soon, 20 hydrogen gas panels will be added to this mix. If all goes well, more panels will be installed on a piece of land in the street. This will allow the other 39 families in the street to benefit from the project as well. The hydrogen gas produced in the summer will be stored and converted into electricity and heat in the winter.
The hydrogen gas produced in the summer can be stored in an underground pressure vessel until winter. One family would need about 4 cubic meters of storage—the size of a regular oil tank.
For Johan Martens, a test project like the one in Oud-Heverlee is what he and his team have been working towards for years.
We wanted to design something sustainable that is affordable and can be used practically anywhere. We’re using cheap raw materials and don’t need precious metals or other expensive components.
The actual cost of the hydrogen gas panels is still unknown, as the mass production is yet to start. The researchers, however, say that it should be affordable. The emphasis will not so much be on large production units, but rather on the combination of smaller, local systems. It will also require less energy-guzzling transport of energy, whether it’s gas, oil, or electricity.
Last week, Toyota announced that it wants to produce hydrogen gas with a prototype designed by Johan Martens’s team in 2014. This device is a little screen (10 cm2) that the engineers will scale up to a large panel.