The Fraunhofer Institute has developed an all-in-one module for hydrogen production that uses solar power to split water into hydrogen and oxygen. This system, known as a photoelectrochemical cell (PEC), generates its own electricity to perform the water-splitting process, transforming the device into a tandem PEC module designed for flexible and straightforward hydrogen generation.

The development process faced significant challenges due to the volatile nature of hydrogen. Mixing hydrogen with oxygen can lead to a dangerous detonating gas reaction. To prevent this, the tandem cell is designed with two strictly separate areas. A glass pane, coated on both sides with different semiconducting materials, absorbs short-wave light on the upper layer and converts long-wave light into electricity on the lower side. This design allows hydrogen to be produced at the bottom and oxygen at the top, with the hydrogen being captured and stored separately.

The system requires only sunlight and water to begin production. Field tests conducted by the Fraunhofer Institute have shown promising results. Even with limited sunlight in central Europe, a single tandem PEC module with an active area of half a square meter (5 sq. ft.) can produce 150 grams of pure hydrogen per year. Scaling up to 100 square meters (1,000 sq. ft.) would yield 30 kilograms (66 lbs) of hydrogen, providing a hydrogen vehicle with a range of 3,000 kilometers (2,000 miles).

While the current efficiency needs improvement, as commercial solar cells can generate 20 times more energy from the same amount of sunlight, the concept of directly obtaining hydrogen from a single element shows great potential. Continued efforts are expected to enhance the efficiency to practical levels.

 (Source: Fraunhofer & Notebookcheck)