Many future electricity scenarios, including those developed for the Swiss Federal Office of Energy (SFOE), use natural gas to bridge the transition to renewables. But such scenarios are inconsistent with the need to completely decarbonize energy supply. In this study we examined whether natural gas is indeed necessary or useful.

In a project funded by the National Research Program 70, we simulated hourly electricity production from a geographically specified set of renewable energy sources, coupled to consumer demand and the availability of electricity storage [1]. Relying only on domestic renewable electricity production, Switzerland would need either natural gas generation, or investments into new electricity storage such as batteries; natural gas would be the far less expensive option.

However, Switzerland currently imports 75% of its primary energy, mainly in the form of fossil fuels. Reducing these imports by more than half, but not eliminating them entirely, changes the picture dramatically. In this case, neither natural gas nor new storage would be required for the system to provide power when people need it, at average energy prices no higher than today.

Where would the imported renewable energy come from? The ideal source would be offshore wind sites in the North Sea, depicted in the Figure. These produce a stable flow of electricity, more in winter than in summer; this would balance Swiss hydropower production, which is lower in winter. Another potential source would be solar power from the south, such as Morocco. Rather than import natural gas through pipelines, Switzerland could import renewable electricity through power lines, and achieve a wider set of social and environmental objectives.

Figure: One week in January in the 2035 scenarios under different carbon targets: (left) using natural gas as a baseload power source; (middle) using gas as a bridging fuel as per the Swiss Energy Strategy 2050; and, (right) using offshore wind only.

[1] Díaz Redondo, P., van Vliet, O., and Patt, A. (2017) ‘Do We Need Gas as a Bridging Fuel? A Case Study of the Electricity System of Switzerland’. Energies, 10(7), p. 861. Available from:

The professor involved in this project is Prof. Anthony Patt, ESC member and head of the Climate Policy (CP) Group. The CP group is based in ETH’s Department of Environmental Systems Science.