May 23 2019
The South Pole receives sunshine like the rest of the world—and in summer virtually around the clock. Rather than providing research stations in the Antarctic with crude oil for generating the electricity and heating they require, solar hydrogen could be made from sunlight in summer as a substitute. Hydrogen possesses a high energy density, can be stored easily, and can be used as fuel when required later without spoiling the environment. An interestingly simple concept—but one that raises a number of questions. Matthias May (HZB) and Kira Rehfeld (Heidelberg University) now are keen to scrutinize how viable this kind of solar fuel generation might be in Antarctica. Financial support for the project was provided by the Volkswagen Foundation.
The idea: during summer, a module with photovoltaic and catalytic materials is splitting molten ice into hydrogen (H2) and oxygen. The H2 is stored. (Copyright: Heike Cords/HZB)
Besides penguins, it is predominantly scientists who reside in Antarctica—gathering neutrinos, analyzing glaciers and ice cores, and examining how organisms endure the hostile environments. A number of research stations work 365 days and require electricity and heat, a major portion of which is produced from crude oil. Environmental physicist Dr. Kira Rehfeld from Heidelberg University observed how expensive and arduous the transportation of crude oil to this region of the world is, however, when she participated in an Antarctic expedition. Even the minutest leaks are a huge problem for the sensitive ecosystem, which is why stringent precautions must be followed during transport.
Summer at the south
The sun shines in Antarctica around the clock during the summer months and is very strong. Would it not be possible to transform this solar energy into a type of energy that could be easily stored? Rehfeld thought about this idea together with HZB expert Dr. Matthias May when she returned home.
Solar energy can be stored in hydrogen
May is exploring multifaceted material systems that use sunlight to divide water molecules into hydrogen and oxygen. The hydrogen molecules store the energy from light in the form of chemical energy. This chemical energy consecutively can be converted into electrical power (electricity) or heat, with the hydrogen being changed back to just water with no destructive emissions.
And hydrogen can be stored in tanks
A vital point: it is possible to compress and store hydrogen gas in tanks, so that the hydrogen stored in summer can be useful in the winter time as well as when there is no sunshine. Rehfeld and May created a project outline that they presented to the Volkswagen Foundation under the Foundation’s "Experiment" program. The project is currently being sponsored for 18 months with a grant of 120,000 euros. May and Rehfeld will conduct a feasibility study during this time.
But does water-splitting work when it is cold?
They will have to formulate methods for solving many issues: splitting water with solar energy necessitates that photovoltaic thin-film semiconductors must be integrated with electrochemical reactions. However, while photovoltaic converters function quite well even at temperatures below zero, chemical reactions occur very gradually when it is cold. Furthermore, modules for the creation of hydrogen from sunlight must work autonomously and be generally maintenance-free.
However, preliminary solutions do not essentially have to be mostly inexpensive. “The rise of photovoltaics also began with solar cells that were initially very expensive and could only be used in satellites”, argues May.
Supplying the Antarctic stations with crude oil is also extremely expensive and in addition involves high risks to the environment. It is definitely worthwhile to think about alternatives.
Dr. Kira Rehfeld, Environmental Physicist, Heidelberg University