A wind turbine in Rhineland-Palatinate (Photo: Imago / Westend61)
Reading aloud According to plans of the Federal Government, by 2050 80 percent of our electricity should come from renewable sources - above all from wind and solar power. However, this will only work if the Germans cache large amounts of energy in wind gas, according to a study by the Research Center for Energy Networks and Energy Storage at the Technical University of Regensburg and Greenpeace Energy. This is the only way to ensure that the lights do not go out even on calm and sunny days.

Wind gas consists of a mixture of hydrogen, which is produced from excess electricity in electrolysis cells, and the even higher-energy gas methane, which is synthesized from the previously obtained hydrogen. Since all carbon dioxides are bound in the synthesis, which releases the subsequent combustion, the CO 2 balance is neutral. This procedure would even allow Germany to overcome the 80-percent hurdle and, in addition to a completely emission-free power supply, avoid pollution from industry and traffic. Above all, the flexible storage, transport and applications of gas are crucial.

Already today there are huge underground gas storage facilities in Germany that could supply the necessary gas quantities: almost 24 billion cubic meters of wind gas fit into existing cavern and pore storage facilities. With a methane-hydrogen mixture, it would be possible to store over 200 terawatt hours of energy - roughly 5000 times the energy that can be hoarded today in German pumped-storage power plants.

Shortcoming missing equipment

To transform the surplus electricity into gigantic amounts of gas, however, innumerable plants for the electrolysis and synthesis procedures as well as gas power plants for the reconversion must be built. As the surplus at peak times increases sharply with rising wind and solar shares in the electricity mix, the study estimates that electrolysis systems with up to 134 gigawatts of storage capacity would be required. For comparison: The world's largest such plant in operation - opened last July in Mainz - makes just 6 megawatts, or 0.006 gigawatts.

In order to create the power act of a complete decarbonization with the help of wind gas nevertheless, the authors of the study see also the politics in the zugzwang: The wind technology is not considered in the official energy scenarios adequately. For the clean fuel cell cars, for example, the same standards should apply by law as for electric cars with a battery. In addition, the research into efficient technologies for reconversion of electricity must be brought to the fore. After all, financial arguments in favor of wind gas also speak: the initial investment in technology would turn into cost advantages starting around 2035. display

Source:

  • Michael Sterner rt al., Importance and Necessity of Windgas for the Energiewende in Germany, 2015
© science.de - Felix Austen
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