Executive Summary

Switzerland operated a total of 706 hydroelectric power plants with a capacity exceeding 300 kilowatts as of January 1, 2026. Expected average energy production fell in 2025 to 37'162 GWh/a (gigawatt-hours per year), compared to 37'350 GWh/a in the previous year. Expansion through new construction and renovations amounted to approximately 50 GWh/a, led by the Sousbach run-of-river power plant in Lauterbrunnen with 30.5 GWh/a. Two hydroelectric power plants in Valais remain shut down following the 2024 storm, including the Rhône power plant Susten-Chippis with an expected production of 215 GWh/a. For monitoring the Energy Strategy 2050, domestic production amounts to 36'724 GWh/a.

Persons

  • Federal Office of Energy (BFE) (Data collection and monitoring)

Topics

  • Hydroelectric power production and energy supply
  • Energy Strategy 2050
  • Natural hazards and infrastructure damage
  • Energy storage

Clarus Lead

Switzerland is significantly missing its expansion targets for hydroelectric power production: By 2035, 37'900 GWh/a should be achieved, yet in 2025 production was only 36'724 GWh/a – a decline of 176 GWh compared to the previous year. This shortfall is caused by three factors: residual water remediation, low inflows, and ongoing damage from the 2024 storm in Valais. These delays jeopardize supply security at a time when energy storage is becoming increasingly critical for grid stability.

Detailed Summary

The decline in expected production of 188 GWh in 2025 results from several competing effects. On one hand, new construction contributed 50 GWh/a: The Sousbach run-of-river power plant in Lauterbrunnen alone provides 30.5 GWh/a, and the facility in Bondo was restored after the 2017 rockfall. On the other hand, data updates and residual water remediation led to a decrease of 188 GWh. Particularly severe are the consequences of the summer 2024 storm in Valais: Two power plants remain out of service, most notably the large Rhône power plant Susten-Chippis with 215 GWh/a expected production, which has been temporarily set to zero.

Regional differences are substantial: Valais generates 28.1% of Swiss hydroelectric power production (10'469 GWh/a), followed by Graubünden with 21.4% (7'919 GWh/a), Ticino with 9.4%, and Bern with 9.2%. The maximum possible generator output was adjusted to 16'475 MW (minus 101 MW). In 2025, 12 power plants were undergoing renovation and 6 were under construction with expected production expansion of nearly 40 GWh/a. Hydropower covered approximately 58.5% of domestic electricity demand in 2025 (10-year average).

Key Findings

  • Swiss hydroelectric power production in 2025 at 36'724 GWh/a below 2035 target (37'900 GWh/a)
  • 2024 storm damage in Valais leads to outages of up to 215 GWh/a at the Rhône power plant
  • Residual water remediation and low inflows reduce production expectation by 188 GWh/a
  • Hydropower remains the backbone of Swiss electricity supply at 58.5% share

Critical Questions

  1. Evidence: How are production expectations updated following storm damage – does the BFE use forecast models for repair duration of the Rhône power plant, or is the "temporary zero-setting" based on incomplete information?

  2. Conflicts of Interest: Who bears the costs for restoring the two damaged power plants – operators, insurers, or the federal government – and could this create incentives for faster repairs?

  3. Causality: Are the "low inflows" in 2025 the result of drought or reservoir management? How strongly do residual water remediation measures affect the production decline in isolation?

  4. Feasibility: What timeline does the BFE expect for completing the 12 ongoing renovations and 6 new construction projects – will the planned 40 GWh/a expansion be sufficient to reach the 2035 target of 37'900 GWh/a?

  5. Data Quality: Are production expectations based on historical averages or on current climate scenarios that factor in lower inflows due to glacier retreat?

Sources

Primary Source: [Hydroelectric Power Statistics 2025 – Federal Office of Energy] – https://www.news.admin.ch/de/newnsb/fE2dUJAXwqRaZzBX999Rt

Supplementary Resources:

Verification Status: ✓ 04.05.2026

This text was created with the support of an AI model. Editorial responsibility: clarus.news | Fact-check: 04.05.2026