A proposed path for Switzerland
More electric.
Ready for winter.
Electric heating and transport need more electricity. Winter brings the hardest supply test: heating rises while solar output falls.
We propose keeping Gösgen and Leibstadt while operation stays safe and economic for their owners, and developing two new reactors. Beznau’s planned retirement comes before new reactors in our schedule, so suppliers need separate winter supply to replace it. Hydro, useful renewables and further winter delivery remain part of the plan.
Demand and replacement evidence
Explore the 2050 programmeProduction worth keeping
12.6 TWh
Switzerland’s reactors generated this much electricity from October 2024 to March 2025. Nuclear was the second-largest domestic source, after hydro.
Winter generation · BFE table 5
Why winter mattersOur choiceKeep productive reactors, build their successors and secure winter supply between them.
Keep the winter contribution
12.6 TWhElectricity from Swiss reactors in October 2024–March 2025. Nuclear was the second-largest domestic source, after hydro.
Source and limitsTwo reactors leave winter supply to secure
4.6 TWhElectricity still missing over the year with two new reactors in our demanding-weather 2050 case. Other winter supply is still needed.
Same package with the two reactors removed and no replacement added: 13.3 TWh.
Source and limitsReplace Beznau before its successors arrive
The announced retirement comes before our new-reactor dates. Electricity suppliers need a separate winter package for those earlier years.
Source and limits
Keep in viewThe 2050 result uses 2016/17 weather, recorded October water and imports up to 2 GW. Our proposal depends on safety, approvals, credible delivery and viable owner contracts.
How much more electricity?
Electricity used by customers, before network losses.
Observed · 2024
57.5 TWh/year
What Switzerland used
The starting point for our electrification calculations.
Electricity consumption · BFEOur scenario · 2050
94.2 TWh/year
What we plan for
More electric heating and transport, with efficiency gains and an allowance for data center growth.
Demand varies with weather. The data center allowance holds a published 2030 scenario constant through 2050.
Demand assumptions and calculationStart here
How Swiss electricity works
Power, energy, winter supply and storage—explained with real Swiss data.
Follow the guide
Read in order, or choose a chapter
Understand
01Swiss electricity, explained
Power, energy, winter supply and storage, with real Swiss data.
02How much electricity will we need?
Electric heating and transport raise electricity demand. Our central sector scenario is about 93 TWh; the supply programme adds data center growth.
03Keeping Switzerland powered through winter
Keep nuclear and hydro at the centre of winter supply. Add useful renewables, paid flexibility and contracted delivery for the remaining gaps.
Compare
04What our dams can deliver
Prioritise Grimsel 4, Grimselsee and a viable Mattmark winter shift. Their different benefits depend on water, project delivery and paid owner services.
05Where batteries and heat storage help
Use batteries for short gaps, store heat in suitable heating networks, and pay owners for useful services. Keep prolonged winter supply secure.
06The case for keeping nuclear in the mix
Keep safe reactors, replace Beznau on time, and develop new nuclear with evidence from real builds and conditional Swiss delivery dates.
Choose
07Compare the cost of dependable electricity
Prioritise viable nuclear extensions, develop complete new-build offers and pay for winter readiness. Generation prices cover only part of dependable supply.
08Can more solar cover Switzerland’s winter?
Build economical solar with useful output and buyers. See what a much larger fleet costs, how summer sales change the comparison, and what still supplies winter nights.
09Keep the lights on while new nuclear is built
Replace Beznau's output before new nuclear arrives, and buy emergency reserve separately. A timeline, purchasing roles and real Swiss reserve costs.
10A supply plan for 2035, by day and by night
A concrete first package after Beznau, with solar, hydro, existing nuclear and realistic limits on what electric cars can contribute.
11What Switzerland should build by 2050
New reactors reduce the winter supply gap. Our programme combines them with safe extensions, hydro and additional winter electricity.
12A path to reliable Swiss electricity in 2050
Keep safe nuclear plants, develop their successors and build around winter needs. Our proposed direction, priorities and timetable.
Follow the evidence.
See the assumptions.
You should be able to check every number we use. Our source register links to original publications. Model results include their inputs, methods and limits.
We separate observations, calculations, policy targets and scenarios. When evidence is missing, we say so.
Open the source register