New Swiss nuclear plants viable only with state subsidies and much lower costs, ETH study finds

The study at a glance

On Monday, 19 researchers from ETH Zurich and the Paul Scherrer Institute (PSI) published a comprehensive analysis of whether new nuclear power plants could fit into Switzerland's future energy landscape. The study applies four different energy system models for the year 2050, exploring a range of political and economic conditions. The authors stress that their work is not a recommendation for or against nuclear energy, but a scientific contribution to the current policy debate about repealing the country's ban on new reactor construction.

“We will not make a plea for or against nuclear energy.”

When nuclear pays – and when it doesn’t

The models collectively point to a clear bottom line: under today’s market and regulatory framework, new nuclear plants cannot compete against alternatives like solar, hydro, and battery storage. The picture changes only if the state provides direct subsidies and absorbs a share of the investment risk, similar to the support mechanisms already in place for renewables.

Costs matter decisively. The study uses a benchmark of CHF 12,000 per kilowatt, reflecting actual construction expenses seen in recent European and US projects. At that level, even with state backing, three of the four models show new nuclear investments failing to achieve profitability. A substantial reduction in building costs would be a prerequisite for any scenario in which nuclear becomes financially viable.

A net-zero Switzerland without new reactors

Achieving climate neutrality by 2050 does not require new nuclear capacity, the researchers find. Switzerland’s current and planned portfolio of hydropower, photovoltaics, other renewables, and storage is sufficient to meet the net-zero target, provided the country maintains efficient electricity trade with its neighbours.

“It works without it.”

The catch is winter. During the cold months, when solar and hydro output drops, Switzerland would still need to import electricity. New nuclear plants could shrink those import volumes but would not make the country fully self‑sufficient in the winter season. From a technical standpoint, the study notes, new reactors could be integrated into a net-zero electricity system; whether they are built depends purely on economic and political choices.

A polarised debate waiting for numbers

The publication lands in the middle of a heated parliamentary debate over lifting the ban on new nuclear plants, in force since 2017. The study’s twin messages (no to competitiveness today, yes to conditional viability with subsidies) ensure that both advocates and opponents will find support for their positions. Political argument over the numbers themselves is almost certain in the coming months.