(Photo : Wikimedia Commons)


Michael Grätzel and his team at the Laboratory of Photonics and Interfaces at École polytechnique fédérale de Lausanne in Sweden have developed dye solar cells that imitate photosynthesis in plants and techniques for making fuels, such as hydrogen, through solar water splitting.



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To be able to generate hydrogen fuel, the team would either use electricity-generating cells with an electrolyzer that divides the water molecules, or use photoelectrochemical cells that split the water directly into oxygen and hydrogen when exposed to light.



By using the first aforementioned method, Jingshan Luo, Grätzel's post-doctoral student, and his colleagues were able to use the device to convert hydrogen 12.3 percent of the power by the Earth's nearest star on perovskite absorbers, a compound which could be found in the laboratory from simple materials, like those used in the common car batteries, forgoing the requirement of using rare-earth metals to produce usable hydrogen fuel.



The high efficiency of the process would make the technique a rival of the other methods used to convert solar energy, and the number of advantages would put the new approach in the lead.



"Both the perovskite used in the cells and the nickel and iron catalysts making up the electrodes require resources that are abundant on Earth and that are also cheap," explained Jingshan Luo. "However, our electrodes work just as well as the expensive platinum-based models customarily used."



On the other hand, converting solar energy into hydrogen makes the storage of the energy possible, which deals with one of the biggest drawbacks met by renewable sources of power: the need to use the electricity as soon as it is generated.



"Once you have hydrogen, you store it in a bottle and you can do with it whatever you want to, whenever you want it," said Michael Grätzel. Such a gas can indeed be burned - in a boiler or engine - releasing only water vapor. It can also pass into a fuel cell to generate electricity on demand. And the 12.3% conversion efficiency achieved at EPFL "will soon get even higher," promised Grätzel.




Tagsrenewable energy, Hydrogen Fuel, Hydrogen, Hydrogen power, solar power, solar energy, Sun, Star, Sunlight, Hydrogen storage