New study shows: Nu­clear power would make the en­ergy tran­si­tion safer and cheaper - even in the fu­ture

The bill on a se­cure elec­tric­ity sup­ply from re­new­able en­ergy sources (so-called um­brella law) is on its final leg in par­lia­ment. With this fed­eral act, re­new­able en­er­gies are to be mas­sively ex­panded by 2050. But are the goals of this new ref­er­ence sce­nario achiev­able and will we have enough win­ter elec­tric­ity? And can we do with­out nu­clear power plants al­to­gether in the fu­ture? The En­ergy Sci­ence Cen­ter at ETH Zurich was com­mis­sioned by economiesu­isse to in­ves­ti­gate these ques­tions. The re­sults of the study now avail­able show: The fed­eral act is nec­es­sary, but not suf­fi­cient to achieve the am­bi­tious goals (35 TWh of re­new­ables are to be added by 2035, 45 TWh by 2050). In the ref­er­ence sce­nario, net im­ports in win­ter also grow to up to ten ter­awatt hours - this cor­re­sponds to about three times the an­nual elec­tric­ity con­sump­tion of the city of Zurich. Al­ter­na­tive sce­nar­ios with longer op­er­at­ing times of the ex­ist­ing NPPs are sig­nif­i­cantly cheaper and safer. An ad­di­tional, new NPP from 2040 on­wards would fur­ther strengthen se­cu­rity of sup­ply and would also have eco­nomic prospects, al­though there are un­cer­tain­ties re­gard­ing in­vest­ment and fi­nanc­ing costs. At the same time, NPP elec­tric­ity prac­ti­cally does not com­pete with the ex­pan­sion of solar power on roofs - re­new­ables and nu­clear power are not an "ei­ther or", but a "both and".

Longer life­times for nu­clear power plants sig­nif­i­cantly re­duce sys­tem costs and in­crease se­cu­rity of sup­ply

As of today, the Swiss NPPs Bez­nau 1 and 2 are ex­pected to re­main in op­er­a­tion for 60 years, Gösgen and Leib­stadt for 50 years each. This would mean that the last NPP in Switzer­land would be taken off the grid in 2034. This study analy­ses the ef­fects of ex­tend­ing the op­er­at­ing lives of nu­clear power plants to 65 and 80 years re­spec­tively. The re­sults speak for them­selves: Longer life­times make the elec­tric­ity sys­tem around 11 bil­lion Swiss francs cheaper by 2050. This would pay for the sub­sidy mea­sures of the Cli­mate Pro­tec­tion Act re­cently adopted by the Swiss elec­torate three times over. The afore­men­tioned win­ter elec­tric­ity short­fall could be closed by 2050. The NPPs are in sym­bio­sis with pho­to­voltaics and pro­vide re­li­able elec­tric­ity, es­pe­cially in the cold sea­son.

The world does not end in 2050: New NPPs se­cure sup­ply in the long term

A sce­nario with a new NPP from 2040 on­wards also per­forms well in com­par­i­son to the ref­er­ence sce­nario de­signed by the "um­brella law" (sys­tem cost re­duc­tion of around 12 bil­lion Swiss francs and clos­ing of the win­ter elec­tric­ity gap - with­out tak­ing into ac­count the in­vest­ment costs of a new NPP). Un­cer­tain­ties exist with re­gard to in­vest­ment and fi­nanc­ing costs, which is why both sav­ings and ad­di­tional costs are pos­si­ble in the final eco­nomic analy­sis up to 2050. How­ever, since the ob­ser­va­tion pe­riod of the model ends in 2050, the ef­fects of the ex­pan­sion are not fully rep­re­sented. Sub­stan­tial ad­di­tional ben­e­fits in the areas of se­cu­rity of sup­ply with cli­mate-neu­tral elec­tric­ity until around 2100 are very likely.

Nu­clear en­ergy or mas­sive in­creases in alpine solar and wind power - we need at least one op­tion

Fur­ther com­par­isons of sce­nar­ios and sen­si­tiv­i­ties also make it clear that large-scale re­new­able plants can also help to en­sure se­cu­rity of sup­ply in win­ter: Pho­to­voltaics on roofs are mas­sively ex­panded in every sce­nario, but alone they do not pro­vide se­cu­rity of sup­ply. This re­quires ei­ther en­ergy from ex­tended or new nu­clear power plants or an equiv­a­lent ex­pan­sion of wind and alpine solar plants (open spaces). The re­sults clearly in­di­cate that a mul­ti­ple of the ca­pac­i­ties en­vis­aged in the "Solar Ex­press" and the "Wind Ac­cel­er­a­tion Bill" would be nec­es­sary. It is not pos­si­ble to do en­tirely with­out ei­ther NPPs or other large-scale re­new­able plants.

Sen­si­tiv­i­ties show: elec­tric­ity trad­ing in­dis­pens­able in every sce­nario

The study also re­veals in­ter­est­ing facts about the re­la­tion­ship be­tween Switzer­land and Eu­rope: from 2025, the EU plans to re­serve 70 per­cent of grid ca­pac­i­ties for elec­tric­ity trad­ing in the Sin­gle Mar­ket. This could re­strict trade with Switzer­land, which the study de­picts in a sen­si­tiv­ity analy­sis. It shows: with­out an ex­change with Eu­rope, the elec­tric­ity sys­tem will be around 50 bil­lion Swiss francs more ex­pen­sive over­all by 2050. Even greater ef­forts will be needed to cover win­ter de­mand with do­mes­tic pro­duc­tion.

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