What seemingly looks like a blue satellite dish is actually a solar reactor developed by Swiss scientists that not only generated high-efficiency hydrogen, but also reuses byproducts such as oxygen and thermal energy.

The “artificial photosynthesis” solar reactor created by the EPFL is able to decompose hydrogen from water through sunlight.

First, a large curved mirror captures as much light as possible, and focuses the captured light nearly 1,000 times onto the photoelectrochemical reactor suspended in the center, where water is then pumped into the reactor to decompose 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.

EPFL had conducted a 13-day test during August 2020, as well as February and March 2021, in order to understand the operation status under different climate conditions. As pointed out by the actual test, the reactor is able to achieve an average efficiency of more than 20% in hydrogen production through solar power at about 500g of hydrogen each day, which fulfills roughly 50% of power consumption, or more than 50% of annual heating requirement, for four households.

Sophia Haussener, Associate Professor heading the Laboratory of Renewable Energy Science and Engineering at EPFL, commented that the output power of the solar hydrogen reactor, while it doesn’t sound like a lot, has exceeded 2kW, and has surpassed the 1kW cap of the pilot reactor. The research team’s next step for actual applications plans to establish a demonstration plant of several hundreds of kW within a metal manufacturing plant, where hydrogen would be used for annealing, and thermal energy on hot water, while the collected hydrogen could be supplied to nearly hospitals.

 (Cover photo source: EPFL)