New study examines the resilience of the Swiss energy system
Researchers at ETH Zurich and ZHAW have developed a new optimisation model to plan electricity systems that better reflect real world conditions by including normal years and crisis scenarios. For Switzerland, the results are surprisingly clear. Major changes to the energy system are only really necessary if cross‑border electricity trade is reduced by more than about 70% for an entire year. In such rare but severe cases, having backup options becomes essential. A key finding highlights the strategic value of existing liquid fuel reserves (Pflichtlager), which can serve as a cost-effective "insurance" against rare disruptions with only minor technical adjustments.
Traditionally, energy planning focuses either on years, when everything works smoothly, or on crisis scenarios. But reality usually lies somewhere in between. To make this intuition clearer, the researchers use a simple everyday illustration:
Imagine packing for a holiday. You pack clothes for the weather you expect, maybe add some sports gear, and you also throw in an extra T-shirt—just in case. Not because you expect something to go wrong, but because the inconvenience would be annoying if it did. At the same time, you don’t pack double or triple outfits for every possible situation. That would be excessive and impractical.
Energy system planning works the same way. As countries move towards climate‑neutral (net‑zero) energy systems, electricity becomes the backbone of the economy. Overall energy consumption may fall, but the importance of a stable electricity supply increases. While this results in less energy imports overall, interruptions of electricity trading, which is an important component of the Swiss power system today and in the future, could become more impactful.
So the crucial question becomes: what if those electricity imports are sometimes reduced or disrupted? The researchers’ model helps answer this by weighing costs against risks, rather than assuming either perfect conditions or constant crises.
“We need a public debate about the level of insurance that we want to achieve, which risks matter and how likely disruptions are. Without this, we build systems that are either too vulnerable because they’re cheap, or overdesigned and too expensive.”
Dr. Jonas Savelsberg, Co-Author of the paper, Head of Nexus-e Group at Energy Science Center / ETH Zurich
For Switzerland, the results are surprisingly clear. Major changes to the energy system are only really necessary if cross‑border electricity trade is reduced by more than about 70% for an entire year. In such rare but severe cases, having backup options becomes essential. A key finding highlights the strategic value of existing liquid fuel reserves (Pflichtlager), which can serve as a cost-effective "insurance" against rare disruptions with only minor technical adjustments.
This text appeared originally on the ETH Energy Science Center's Website: https://esc.ethz.ch/news/archive/2026/08/new-study-examines-the-resilience-of-the-swiss-energy-system.html.