Engineers at EPFL have built and tested a solar reactor that can generate hydrogen gas from sunlight and water. The system is not only highly efficient at producing hydrogen, it also captures the “waste” products of oxygen and heat to put them to use too.

Hydrogen is set to be a key player in renewable energy, and one of the most effective ways of producing it is by splitting water into its constituent molecules. When done using solar energy, this process is called artificial photosynthesis, and that’s the process this new reactor is tapping into.

The EPFL reactor looks like a satellite dish, and it works on a similar principle – the large curved surface area collects as much light as possible and concentrates it onto the small device suspended in the middle. In this case, the dish is collecting the heat from the Sun and focusing it by around 800 times onto a photoelectrochemical reactor. Water is pumped into this reactor, where the solar energy is used to split its molecules into hydrogen and oxygen.