Summary

Switzerland faces a critical energy supply crisis in winter. A comprehensive study by energy company Axpo shows: Without substantial measures, massive electricity shortages threaten with significant economic and social consequences. The study presents two solution scenarios – either the construction of large centralized gas power plants or a reversal of the nuclear phase-out. The expansion of rooftop photovoltaics alone is insufficient and economically inefficient.

People

Topics

  • Winter electricity supply and power shortages
  • Renewable energy versus nuclear power
  • Gas power plants as transitional solution
  • Energy transition and decarbonization
  • Switzerland's electricity import dependency

Clarus Lead

Switzerland urgently needs new capacity for winter electricity supply – as shown by a study by energy company Axpo. The core problem: With the gradual phase-out of nuclear energy, 40 percent of winter production will be lost, while demand increases in cold months and renewable energies are produced mainly in summer. The study, developed by 50 expert specialists together with scientists from ETH Zurich and the Paul Scherrer Institute, proposes two concrete scenarios to close the emerging electricity gap.

Detailed Summary

The Core Problem of Winter Supply

Switzerland already imports nearly as much electricity in winter as during the crisis winters of 2022/23. The reason lies in seasonal asymmetry: While photovoltaics and hydropower provide electricity mainly in summer, electricity consumption in winter is significantly higher. With the planned phase-out of nuclear energy, this gap widens dramatically. According to the study, hydropower offers only limited expansion potential, as storage capacity is already nearly exhausted.

Wind Energy as a Source of Hope

The Axpo study rates wind power surprisingly positively. It delivers two-thirds of its annual production in the winter half-year and is cost-effective compared to other technologies (only 6 cents/kWh subsidy). An accelerated expansion is recommended with emphasis. However, approval procedures remain a major obstacle – currently wind projects take over ten years on average. The study calls for consistent implementation of the acceleration decree, additional suitable areas, and waiving municipal vetoes.

Solar Energy: Economically Inefficient for Winter Electricity

The study's assessment of rooftop photovoltaics is surprisingly critical. Although socially popular, it produces only 8 percent of its annual output in winter (December–February). An expansion path that primarily relies on rooftop solar would significantly increase the cost of the energy transition. The subsidy requirement for winter electricity is four to five times higher than for nuclear power (35 vs. 8 cents/kWh). The study also identifies a "hidden subsidy": solar system owners do not pay grid fees for self-consumption, unfairly shifting costs to other electricity customers.

Scenario 1: Gas Power Plants as Flexible Bridge Solution

The first scenario combines solar and wind power with large centralized gas power plants that actively participate in the electricity market. This flexibility enables optimal supplementation to fluctuating renewable production. Market-active gas power plants are significantly cheaper than pure reserve power plants and generate ongoing electricity market revenue. Operation from 2035 is technically possible but requires timely regulatory frameworks for subsidies, CO₂ charges, and waste heat utilization. Critical: Initially diesel would be used, not low-carbon alternatives. Greenhouse gas emissions would initially increase but could be compensated long-term through accelerated electrification.

Scenario 2: Nuclear Power as Stabilization Factor

The second scenario hinges on reconsidering the nuclear phase-out. Nuclear power plants reliably deliver large amounts of electricity in winter and reduce import dependency. Extended operation of existing nuclear power plants is the most economically efficient option. New construction (Leibstadt/Gösgen) would cost 8.6–12.5 billion francs, with government subsidies of 20–60 percent of investment. New construction would constitute an unprecedented effort – up to 10,000 people simultaneously on the construction site (by comparison: NEAT construction with a maximum of 4,000 people). Implementation by 2050 requires lifting the new construction ban, accelerated permits, funding instruments, and innovative financing models (e.g., the British system with user cost participation during construction phase).

Key Findings

  • Urgency: Without substantial measures, significant winter electricity shortages threaten with massive economic consequences
  • Insufficiency of Solar Alone: Rooftop photovoltaics cannot close the electricity gap and is four to five times more expensive than nuclear power for winter electricity production
  • Two Real Options: Either large gas power plants (possible from 2035) or reversal of the nuclear phase-out (new construction by 2050)
  • Wind Power Priority: Winter value and cost efficiency make accelerated wind expansion an indispensable component of both scenarios
  • Regulatory Necessity: Both solutions require rapid political decisions and legal frameworks

Critical Questions

  1. Data Quality of Forecasts: What uncertainty margins and sensitivity analyses underlie the import dependency and demand scenarios? How robust are the assumptions with changed electrification rates (e.g., heat pumps, e-mobility)?

  2. Conflicts of Interest at Axpo: To what extent does Axpo's independent electricity business (production, trading, supply) influence study results? What economic incentives does the company have to favor nuclear power or gas power plants over other technologies?

  3. Alternative Scenarios: Were hybrid solutions (e.g., large-scale storage, demand-side management, interconnections to the EU) analyzed with equal depth? Why are these not presented as equally valid options in the summary?

  4. Implementation Risks Gas Power Plants: How realistic is operation start-up in 2035 given current regulatory obstacles and political resistance to fossil infrastructure? What scenario costs arise with delays?

  5. Financing Models Nuclear New Construction: Is the British financing model transferable to the Swiss electricity market structure? What risks emerge for private investors with cost overruns and construction delays?

  6. Climate Balance Gas Power Plants: How is the accumulated greenhouse gas burden assessed during a 20–30-year transition phase with natural gas? At what CO₂ capture and storage rate does the climate balance actually turn positive?

Bibliography

Primary Source: Neue Zürcher Zeitung – "According to Axpo, Switzerland must decide: Either build large gas power plants or new nuclear power plants" – 24.03.2026

Supplementary References from Article:

  • Axpo Study (50 expert specialists, supported by ETH Zurich and Paul Scherrer Institute)
  • Interview Martin Neukom (Zurich Energy Director) – 19.03.2026
  • Commentary David Vonplon: "Switzerland Says Goodbye to the Illusion of a Nuclear-Free Future" – 13.03.2026
  • Interview Jürg Grossen – 07.03.2026

Verification Status: ✓ 24.03.2026

This text was created with support of an AI model. Editorial Responsibility: clarus.news | Fact-Check: 24.03.2026