Kira Rehfeld from Heidelberg University was struck by Antarctica's intense light when she visited it for her research. It's always sunny in summer. She observes that this solar radiation could be used to provide energy for the research infrastructure. Global warming has meant that generators, engines and heaters in remote areas have largely been powered by fossil fuels such as petrol or petroleum. Not only are there high economic costs but also pollution from even the smallest of spillages is a serious threat to the ecosystem.Hydrogen could replace fossil fuels, but it is versatile and can be stored at very low temperatures. "We therefore had the idea to use solar modules to generate climate-neutral hydrogen at site during Antarctic summer by splitting water in hydrogen and oxygen using electrolysis," May, then a postdoctoral researcher at the Helmholtz Zentrum Berlin Institute for Solar Fuels, said. May and Rehfeld applied for funding from Volkswagen Foundation to study whether hydrogen can still be produced using sunlight at sub-zero temperatures and which method is most suitable for this. Although electrolysis efficiency can be significantly reduced by low temperatures, most solar modules work better at cold temperatures.Moritz Klbach and May, his HZB colleague have now empirically compared two approaches. One is a traditional setup where the photovoltaic modules are physically and thermally separated from the electrolysis tanks. The other is a thermally coupled setup, in which the module is in close contact to the wall of an electrolysis tank. This promotes thermal diffusion. Klbach used a freezer to simulate Antarctic conditions. He cut a hole in the cabinet's door and installed a quartz window. The cabinet was then illuminated with simulated sunlight. The electrolysis container was filled with 30% sulphuric (also known by battery acid), which has a freezing point of -35 degrees Celsius. It conducts electricity well.Klbach set up the cells and performed the measurements. The thermally coupled PV module produced significantly more hydrogen than the one without. This is because the PV modules are illuminated and pass their heat directly to the electrolyser. We were able to improve the efficiency of the electrolyser by adding thermal insulation. Klbach says that the electrolyte temperature rose during illumination, from -20 to as high at +13.5 degrees Celsius."This study confirmed that thermally coupled systems may have a higher efficiency than those that are thermally decoupled. It remains to be determined if these advantages can be economically exploited. "We want to test prototypes in real-world conditions during the next phase. This will be an exciting endeavor and we are looking for partners to do so," May says.Solar hydrogen that is locally produced could be an alternative to fossil fuels. It would also eliminate the pollution threat to the environment and CO2 emissions. This could not only work at the South Pole but in other regions where it is extremely cold and sparsely populated. These could include Canada, Alaska, the High Alps, Canada, Alaska, and other mountainous areas like the Himalayas.May says that solar-generated hydrogen may be feasible in remote areas of the world. This is in reference to the 60-year-old triumph of photovoltaics which supplied power to satellites orbiting the Earth.
