A team from the Helmholtz-Zentrum Berlin, Ulm University, and Heidelberg University has now investigated how hydrogen can be produced at the South Pole using sunlight, and which method is the most promising. Their conclusion: in extremely cold regions, it can be considerably more efficient to attach the PV modules directly to the electrolyser, i.e. to thermally couple them. This is because the waste heat from the PV modules increases the efficiency of electrolysis in this environment. The results of this study, which has now been published in Energy & Environmental Science, are also relevant for other cold regions on Earth, such as Alaska, Canada, and high mountain regions, for example. In these places, solar hydrogen could replace fossil fuels such as oil and petrol.
When environmental physicist Kira Rehfeld, from Heidelberg University, visited Antarctica for her research, she was struck by the intense light there. “It's always light in summer. This solar radiation could actually be used to supply the research infrastructure with energy“, she observes. However, generators, engines, and heaters in these remote regions have mostly been powered until now by fossil fuels delivered by ship, such as petroleum or petrol, which cause global warming. Besides the high associated economic costs, pollution from even the smallest spills is also a major problem threatening the especially sensitive ecosystem.
Looking for ecofriendly solutions
Fossil fuels could be replaced by hydrogen, though, a versatile energy medium that in addition is able to be stored extremely well at low temperatures. “Our idea was therefore to use solar modules to produce climate-neutral hydrogen on site during the Antarctic summer by splitting water into hydrogen and oxygen through electrolysis”, says May, then a postdoc at the Helmholtz-Zentrum Berlin Institute for Solar Fuels. Rehfeld and May applied for funding from the Volkswagen Foundation to investigate whether hydrogen can be generated using sunlight even at sub-zero temperatures, and which method is best suited for this. Low temperatures can considerably reduce the efficiency of electrolysis, though cold actually increases the efficiency of most solar modules.
Read more at Helmholtz-Zentrum Berlin für Materialien und Energie
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