An integrated solar cell that produces hydrogen as a form of energy storage is being investigated by researchers at the Ecole Polytechnique Fédérale de Lausanne
(EPFL), in Switzerland. Converting solar to hydrogen is hardly a new idea, but so far solutions to the problem have been very costly. The EPFL system sidesteps this problem by using iron oxide, better known as rust, and water.
Of course, this is not common-or-garden rust but ‘nanostructured rust’: enhanced with silicon oxide and covered with a nanometer-thin layer of aluminum oxide and cobalt oxide. But it is still cheap to produce, say scientists at EPFL. The one drawback is low efficiency. At 1.4% to 3.6%, the prototype is not going into production anytime soon.
However, researchers are confident they can attain efficiencies of 10% in a few years, for less than USD$80 per square metre.