A pilot-scale parabolic dish solar reactor constructed on the campus of École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland, has been demonstrated to efficiently generate hydrogen and heat.

With an output power of 2 kW, the photoelectrochemical system concentrates solar radiation nearly 1,000 times to convert water into valuable and renewable hydrogen, oxygen and heat. Water pumped into the reactor is electrolyzed to yield the gases while the heat produced is passed through a heat exchanger so that it can be harnessed for ambient heating and other applications.

SoHHytec SA, an EPFL spinoff, is currently partnering with a Swiss-based metal production facility to build a demonstration plant at the multi-100-kW scale to provide hydrogen for metal annealing processes, oxygen for nearby hospitals, and heat for the factory’s hot-water needs.

Efforts are also underway to scale up the system to provide residential and commercial central heating and hot water, and to power hydrogen fuel cells. At an output level of about half a kilogram of solar hydrogen per day, the campus system could power around 1.5 hydrogen fuel cell vehicles driving an average annual distance. This output could also satisfy up to half the electricity demand and more than half of the annual heat demand of a typical four-person Swiss household.

The system described in Nature Energy has achieved a solar-to-hydrogen device-level efficiency of greater than 20% at a hydrogen production rate exceeding 2.0 kW (0.8 g/min).

To contact the author of this article, email shimmelstein@globalspec.com