May 22, 2017
How do we store solar energy for periods when the sun doesn’t shine? We do know that solar energy can be stored by converting it into hydrogen. The problem? Current hydrogen-production technologies have given promising results in the lab, but they are still too unstable or expensive and need to be further developed to use on a commercial and large scale.
The good news is that researchers at École Polytechnique Fédérale de Lausanne and Swiss Center for Electronics and Microtechnology have now designed a device that outperforms in stability, efficiency and cost, using commercially available solar cells and none of the usual rare metals.
The approach taken by the researchers is to combine components that have already proven effective in industry in order to develop a robust system.
Their prototype is made up of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals.
The electrochemical part of the process requires a catalyst made from nickel, which is much less expensive and widely available.
Hydrogen that goes the distance
The device converts solar energy into hydrogen and has already run for more than 100 hours straight under test conditions. The method, which surpasses previous efforts for stability, performance, lifespan and cost efficiency, is published in the Journal of The Electrochemical Society.
A 12-14m2 system installed in Switzerland would allow the generation and storage of enough hydrogen to power a fuel cell car over 10,000km every year”, says Christophe Ballif, who co-authored the paper. “In terms of performance, this is a world record for silicon solar cells and for hydrogen production without using rare metals.”