While solar power typically brings to mind shiny solar panels, another way to harness the sun’s energy is to convert it into fuels. Plants do this effortlessly. And scientists have been trying to copy them for years to make solar fuels that can be stored for use when sunlight isn’t available.
Researchers have developed a solar fuel system that could be easily scaled up to practical commercial devices. The device uses sunlight to split water into hydrogen for storage as fuel. The team from Forschungszentrum Jülich (Jülich Research Center) in Germany published their findings in Nature Communications.
Photosynthesis is the process by which plants convert light into chemical energy to make simple carbohydrates from carbon dioxide and water. Artificial photosynthesis systems, also called artificial leafs, typically emulate water-splitting using solar cells and catalysts.
The concept of solar-powered water-splitting has been around since the 1970s. But most research to date has been on laboratory-scale experiments focusing on better absorber materials and catalysts to improve efficiency.
To make a practical system, the German researchers made a base unit that can be repeated to make as large an area as desired. The base unit consists of three thin-film silicon solar cells connected in series. On the backside of each cell, the researchers created two electrolyzer electrodes made of nickel foam.
To showcase its scalability, the researchers put together 13 base units to make a device with an area of 64 cm2. Currently, the device only has an efficiency of 3.9 percent, but the researchers said “there’s still plenty of room for improvement” and that the efficiency could be increased to 10 percent with other solar cell materials.