Researchers have developed a solar powered system that splits water at -20 ° C. The technology could serve as a renewable fuel source at high altitudes and in polar environments.
The distribution of fossil fuels to remote locations with cold climates, such as research stations in Antarctica, poses a number of challenges. These include the cost and difficulty of getting the fuel (usually diesel) to these locations and the potential for contaminating sensitive ecosystems in the event of a spill, in addition to the CO2 emissions generated by their use.
Using hydrogen as a fuel is preferable to fossil fuels because it is renewable and has very little, if any, contribution to the greenhouse effect. In areas where the temperature is regularly below freezing, hydrogen can be easily stored in tanks, so a method of local hydrogen production would go a long way towards meeting the energy needs of remote populations. One problem with this is that most conventional methods of making hydrogen do not work well at sub-zero temperatures.
Now a research team in Germany led by Matthias May from the University of Ulm has developed a technology that enables hydrogen to be produced at low temperatures. The process works by using electrolytes with low freezing points, such as dilute sulfuric acid, to enable the use of water at lower temperatures. This is combined with strict thermal control of the entire device in order to avoid heat loss to the environment and to transfer additional thermal energy from the solar cell to the electrolyte, which leads to an internal working temperature of around 10 ° C.
May says a commercially viable version of this system could be widely used. “Antarctica is an extreme example, but even in places like Mongolia or in mountainous regions there are large parts of the year when it is actually very sunny, but the temperatures are close to 0 ° C or below … it is actually quite a fraction the population of the world who live in such areas. ‘
Gary Moore, an expert on water splitting at Arizona State University in the US, says, “The research opens avenues for the development of such niche applications into technologies with global market penetration.”
Many solar fuel researchers believe hydrogen can wean the world from fossil fuels – Moore sees this work as an important step in making that vision a reality.