Swiss voters are expected to decide in February 2027 whether new nuclear power plants should again be permitted in Switzerland. If voters say yes, a decisive economic question arises: can a new nuclear power plant be built and financed so that it produces electricity at competitive costs?
CHF 10 to 15 Billion for a New Nuclear Power Plant
In the debate over new nuclear plants, a study by the Swiss Academies of Sciences estimated costs of up to CHF 43 billion. That figure, however, refers to a particularly large reactor whose construction is also marked by severe cost overruns. For a power plant the size of Gösgen, Avenir Suisse estimates in a new analysis costs of CHF 10 to 15 billion, similar to what the Gotthard Base Tunnel cost.
This estimate, however, assumes that lessons are learned from the delays and cost overruns of recent projects in Europe and the United States, and that a proven, fully designed reactor type is used. In the baseline scenario, the electricity produced costs about CHF 172 per megawatt-hour.
Nuclear Power Can Compete with Solar
How competitive nuclear power really is, however, only becomes clear when compared with other sources of electricity. At first glance, solar power often appears cheaper than electricity from a new nuclear plant. But production costs alone tell only part of the story.
Timing matters too. Solar power is often generated when there is already a lot of electricity available in the grid and prices are low. In 2025, solar power achieved an average of only CHF 56 per megawatt-hour, against an average wholesale price of about CHF 100. Additional grid expansion costs come on top. Taking these factors into account, electricity from larger solar installations costs about CHF 160 per megawatt-hour, on par with nuclear power. Small rooftop systems, at around CHF 280, are considerably more expensive.
Political Risks Make Financing More Expensive
Even if nuclear power can keep pace with solar, that does not yet make it competitive. The cost of electricity from a new nuclear plant exceeds the average wholesale electricity price of recent years, which, however, is distorted by various subsidies. Whether this situation changes depends largely on the terms under which a new plant can be financed. This is where policy comes into play.
A nuclear power plant takes about ten years to build and must then sell electricity for 60 years. A later decision to phase out nuclear power, as in Germany, can devalue such an investment in one stroke. Investors therefore demand a high risk premium, and it makes a major difference: if financing costs fall from 8 to 5%, the levelized cost of electricity drops by one third.
A Clear Compensation Rule Instead of Subsidies
Do new nuclear plants therefore need loan guarantees, subsidies, or guaranteed electricity prices? Avenir Suisse considers this the wrong approach: risks from construction delays, cost overruns, or low electricity prices should remain with investors and not be passed on to the public. The state should only minimize the risk it creates itself.
Avenir Suisse therefore calls for more predictable approval procedures and a clearly defined compensation rule in case policymakers later halt a plant. The United Kingdom has such a rule for the Hinkley Point C plant, and Switzerland a similar principle for hydropower. The same standard should apply to all electricity sources: inefficient subsidies, for example in the solar sector, should be abolished. And if the market fails to provide enough secure winter capacity, the state should compensate that service directly rather than promote a specific technology.