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Researchers from Empa and the University of Geneva have calculated that it would take ten times more photovoltaic energy and 120 times more wind power to reduce Switzerland’s dependence on foreign countries. .
The researchers advocate a massive increase in wind energy production which should increase to twelve terawatt hours, once morest 0.1 TWh currently. Solar should also increase sharply.
20min/Matthias Spicher
More heat pumps in buildings, more electric cars on the roads. These trends, which respond to Switzerland’s strategy to achieve climate neutrality by 2050, will result in an increase in the demand for electricity in our country. But today, Switzerland is already dependent on imports from neighboring countries, up to 11% of its consumption. Imports which also have a high carbon footprint, as many come from gas or coal-fired power stations. As a result, researchers from Empa and the University of Geneva have worked on scenarios to reduce this dependence, while focusing on renewable energies.
20% more electricity needed
The researchers therefore calculated the additional electricity needs in Switzerland in the coming years. They estimated them at around 12 terawatt hours per year. That is 20% more than today. In addition, it will be necessary to replace nuclear electricity, since the Federal Council plans to phase out the atom gradually. However, this replacement must be done by renewable energies which are much more irregular in terms of productivity, note the scientists.
The researchers therefore developed different scenarios and analyzed how the Swiss electricity mix should be composed, in order to minimize imports – and therefore the greenhouse gas emissions linked to electricity. According to them, the share of imported electricity will increase anyway and therefore the CO₂ emissions too. But these will be partially offset by the increasing electrification of heating and mobility, which will reduce these emissions by up to 45%.
Especially needs in winter
It is especially in winter that Switzerland will depend on foreign countries because of the lower yields of solar energy. In the eyes of the researchers, the scenario that has obtained the best results in terms of emissions reduction calls for a tenfold increase in solar power to 25 terawatt hours (currently 2.7 TWh), and a massive increase in wind power of around 12 terawatt hours ( 0.1 TWh currently), so 120 times more than today. “This energy is mainly produced in winter and at night,” explains Martin Rüdisüli. “So it can help reduce our dependence on imports during these times.”
The authors of the study further believe that seasonal energy storage is a growing challenge. In all the scenarios calculated, large electricity surpluses are to be expected in summer due to the development of photovoltaics. According to the researchers, the greatest potential for transferring these surpluses in winter lies in “Power-to-X” technologies, which allow the transformation of excess electricity into storable chemical energy carriers such as hydrogen or synthetic methane, as well as than in thermal accumulators such as geothermal probe fields.
Currently, the electricity imported into Switzerland comes mainly from gas or coal-fired power stations, which are responsible for around 25% of all greenhouse gas emissions in Europe. While in Switzerland, the current comes mainly from hydraulics and nuclear, technologies with a low carbon footprint.
According to the researchers, the electricity produced in Switzerland generates 40 g of CO2 equivalents per kilowatt hour. But the average for the entire Swiss electricity mix – including imports – is around 108 g. “At peak times, it can even go up to 600 g”, according to Martin Rüdisüli, of the Federal Laboratory for Materials Testing and Research (Empa). Imported electricity is therefore very polluting.
(cht)