In an effort to make solar energy generation a lucrative option for utility companies over the globe, researchers are on a hunt to develop systems that could affordably store solar energy for peak use. While companies such as LightSail Energy are planning to store renewable energy as compressed air, researchers at EPFL have come up with a way to store solar energy as hydrogen.
While there is nothing new in storing solar energy as hydrogen, current technology is expensive and would cost about $10,000 to cover a 10 square centimeter surface. Though, current technology has a decent efficiency of 12.4 percent, the high cost of materials employed makes it too expensive. Researchers at EPFL wanted to make something that could readily be produced and could effectively store solar energy as hydrogen by splitting water.
The solution came by using iron oxide, rust, enhanced with silicon oxide, covered with nanometer-thin layer of aluminum oxide and cobalt oxide to optimize the electrochemical properties of the material. The second part of the device is composed of dye and titanium dioxide, the basic ingredients of a dye-sensitized solar cell. This layer lets the electrons transferred by the iron oxide gain enough energy to extract hydrogen from water.
Though the materials make the cell relatively inexpensive with researchers expecting that the device should cost only $80 per square meter, the efficiency is quite modest – between 1.4 and 3.6 percent. However, the researchers are confident that the tandem solar cell could hit an efficiency of up to 16 percent with the same materials with some added improvements.