artificial photosynthesis for Hydrogen

A Solar Hydrogen System That Produces Both Heat And Oxygen

What looks like a blue satellite dish is actually a Swiss-developed solar reactor that not only generates high-efficiency hydrogen but also reuses wastes such as oxygen and heat energy. The EPFL’s “artificial photosynthesis” solar reactor can breakdown hydrogen from water using sunlight.


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.

After capturing as much light as possible, a giant curved mirror focuses the captured light roughly 1,000 times onto the photoelectrochemical reactor suspended in the center, where water is then fed into the reactor to breakdown hydrogen and oxygen using electrolytic water. The reactor can also capture by products, such as oxygen and thermal energy, where oxygen can be applied on medical and industrial purposes, and thermal energy can be used for heating through heat exchangers.

The reactor was tested on the EPFL campus for 13 days in August 2020, February and March 2021, to see how it performed in various weather situations.

Its average solar-to-hydrogen efficiency was determined to be more than 20%, producing around 500 g (1.1 lb) of hydrogen each day. According to the researchers, with this output, the system could run 1.5 hydrogen fuel cell vehicles traveling the average distance for a year, or provide almost half of the electrical needs of a four-person family.

The next step for the study team is to build a demonstration plant of many hundreds of kW within a metal manufacturing factory, where hydrogen would be used for annealing and thermal energy would be utilized on hot water while the collected hydrogen could be supplied to nearly hospitals.

Reference- New Atlas, Journal Nature Energy, Interesting Engineering, National Geographic