At an initial glance, the parabolic reflector might be mistaken for ordinary telecommunications apparatus. However, the one situated on the EPFL campus stands unparalleled – functioning as a faux tree. A reactor perched atop the dish harnesses sunlight to metamorphose water into green hydrogen, oxygen, and warmth. This unique contraption marks the premier full-system manifestation of solar-powered hydrogen generation.
“In contrast to standard laboratory-scale exhibitions, our setup encompasses all supplemental devices and constituents, providing a clearer insight into the attainable energy efficiency of the entire system, as opposed to the gadget in isolation,” elucidated Sophia Haussener, chief of the Laboratory of Renewable Energy Science and Engineering within the School of Engineering, in an announcement.
The venture is predicated on exploratory investigations that established the notion at a lab scale, employing LRESE’s potent solar simulator. The group has now divulged their “amplified, effective, and multifaceted procedure” in genuine circumstances via Nature Energy.
“Surpassing 2 kilowatts of output power, we’ve breached the 1-kilowatt threshold for our trailblazing reactor while preserving unrivaled efficiency at this magnitude. The hydrogen fabrication pace attained in this undertaking signifies a promising stride towards the commercial actualization of this innovation,” Haussener conveyed.
This system can energize hydrogen fuel cells and supply residential and commercial central heating. The dish focuses the sun’s beams, subsequently injecting water into its focal point, where a photoelectrochemical reactor resides. Within this chamber, photoelectrochemical cells employ solar power to electrolyze or disintegrate water molecules into hydrogen and oxygen.
Simultaneously, thermal energy emerges, coursing through a heat exchanger that harnesses it rather than dissipating it as a system loss. The oxygen molecules liberated by the photoelectrolysis reaction are also recuperated and utilized. “Oxygen is often deemed a byproduct, yet in this instance, it can be effectively captured – for instance, for medicinal applications,” Haussener asserted.
The technology is already experiencing commercial implementation. LRESE-spinoff SoHHytec SA collaborates with a Swiss metal production establishment to construct a demonstration facility at a multi-100-kilowatt scale, generating hydrogen for “metal tempering procedures, oxygen for neighboring medical centers, and warmth for the factory’s hot-water necessities.”
Additionally, the system can energize hydrogen fuel cells and offer residential and commercial central heating. Per the press release, the EPFL campus system can power roughly 1.5 hydrogen fuel cell vehicles traversing an average annual distance or satisfy up to 50% of the electrical consumption and over 50% of the yearly thermal demand for a typical Swiss family of four, yielding around half a kilogram of solar hydrogen daily.