Comparison

What does a kilowatt hour cost in winter?

Every technology delivers part of its power in winter and part in summer. Here, the winter kWh carry the full cost. Solar power counts for nothing in summer. Power from nuclear and wind, which flows around the clock, counts for 4 centimes in summer.

A cloud of steam above the cooling tower of the Gösgen nuclear power plant against the evening sky — Gösgen nuclear power plant: running since 1979, it would reach 60 years in 2039. Photo: Joris Egger, CC BY-SA 4.0

Wind turbines on the Jura pastures of Mont Crosin under a blue sky — Mont Crosin wind farm in the Bernese Jura, the largest in Switzerland. Photo: Rapipolo, CC BY-SA 4.0

Cost per kilowatt hour in the winter half-year, in centimes

The bar shows the range from cheap to expensive assumptions, the line the middle one.

Windnow, permits difficult

17–26

New nuclear plant2045 at the earliest, more likely 2050

10–51

Solar, roofs (Swiss Plateau)now

24–63

Solar, alpinenow, permits difficult

29–57

Solar, facadesnow

37–78

Seasonal batterynow

far outside: 1’437 to 4’141 ct.

23 CHF

Assumptions: lifetime of 30 years for solar, 20 years for batteries, 60 years for nuclear. Real interest rate of 2 to 5 percent, 3 to 7 percent for nuclear. Nuclear construction costs of 6’000 to 16’000 CHF per kW, construction time of 8 to 15 years. All values and sources on the page Assumptions and sources.

New nuclear plant: cheap on paper, but risky

With the construction costs from the BAK Economics study for economiesuisse (the Swiss business federation), a winter kWh costs around 19 centimes.29 With costs like those of Britain’s Hinkley Point C, it is over 50 centimes.31 It would deliver power in 2045 at the earliest, more likely 2050.32

Wind: the cheapest new winter source

Around 22 centimes per winter kWh. But permits today often take ten years or more.

Solar on the Swiss Plateau: expensive for winter, but available now

As overcapacity together with wind and storage lakes, it closes the gap, without decades of construction and without the cost risk of a large project.

Seasonal battery: ruled out

Each kilowatt hour from it costs more than 50 times as much as from any other solution.

The cheapest is what already exists

Running Gösgen and Leibstadt for 80 instead of 60 years costs the least. The Federal Council considers this technically feasible.28 But it only postpones the question by 20 years.

The scenarios for 2050 compared

Scenarios for 2050 compared
Scenario 2050	Imports in winter	Surplus per year	Cost per year	per kWh	Available
2050 under the Electricity Act, without nuclear	5.5 TWh (above guideline)	19.8 TWh	4.9 bn CHF	7.2 ct.	step by step until 2050
Solar deliberately oversized	0.0 TWh	35.4 TWh	7.3 bn CHF	10.6 ct.	step by step until 2050
Renewable mix with more wind	0.0 TWh	28.1 TWh	6.2 bn CHF	9.0 ct.	step by step until 2050, permits for wind difficult
Store the summer in batteries	0.0 TWh	13.1 TWh	119.4 bn CHF	173.8 ct.	battery technically available now
A new nuclear plant from 2050	0.0 TWh	26.8 TWh	5.7 bn CHF	8.4 ct.	nuclear plant in 2045 at the earliest, more likely 2050
Gösgen and Leibstadt run for 80 years	0.0 TWh	31.5 TWh	5.1 bn CHF	7.4 ct.	running beyond 60 years requires approval

Cost per year: new solar plants and wind turbines, battery, nuclear plants and imported power, at today’s prices. Existing hydropower, the grid and levies are not included, because they are the same in all scenarios. Surplus: power that has to be exported or curtailed.