Security of supply and climate neutrality by 2050

Energy security can no longer be taken for granted, and the risk of an energy shortage is a bitter reality. "The failures of the last ten years weigh heavily. The course for a secure, sustainable energy supply must be set now," says Michael Wider, President of VSE. The study Energy Future 2050, which VSE carried out in close cooperation with Empa, is the first scientific modeling to simulate Switzerland's overall energy system across sectors up to the year 2050, taking into account neighboring countries as well.

Empa researchers Matthias Sulzer and Martin Rüdisüli were responsible for the scientific lead of the study. Over a period of around two years, they worked with a team of scientists and numerous industrial partners to create a unique database that covers all energy sources and all sectors. "Previous work has usually only dealt with individual aspects or simplified models. The model that has now been created provides for the first time a holistic overview of our energy system," says Sulzer. In addition, it can also be used for further studies: "New findings or changed framework conditions can easily be integrated.

The study shows various possibilities, including constraints, costs and necessary framework conditions, for achieving energy and climate policy goals with today's technology. Energy Future 2050 is based on four representative scenarios along two dimensions, "domestic acceptance for new energy infrastructure" (defensive vs. offensive expansion) and "energy policy relationship with Europe" (isolated vs. integrated energy market).

These are the twelve core results for the transformation of our energy supply up to the year 2050:

1. Without a massive acceleration in the expansion of new capacity and a massive increase in efficiency, focused conversion and expansion of the grids, and a close energy exchange with Europe, we will not achieve the energy and climate targets. 
   The current rate of expansion of photovoltaics (PV) and especially wind power will not be sufficient to achieve Switzerland's energy and climate targets by 2050, and Switzerland would have to continue to rely partially on fossil fuels. With the current addition rate of PV of the last two years, the defensive scenarios lack up to 7 GW or 20% of the necessary solar production. In the case of wind power, which is currently not being expanded at all, there will be a shortfall of around 1.2 GW in the offensive scenarios at the current rate of expansion in 2050.
2. The demand for electricity in Switzerland will increase.
   Switzerland's base electricity demand will decrease slightly by 2050 due to improved technology and efficiency measures. Nevertheless, the substitution of fossil fuels in the transport and heating sectors will lead to a strong increase in electricity demand from 62 TWh today to 80-90 TWh in 2050. Depending on the scenario, this corresponds to an increase of 25-40%. Due to the increasing electricity demand and the successive decommissioning of Swiss nuclear power plants by 2044, a production gap of 37-47 TWh arises, which has to be filled by the addition of new plants.
3. High acceptance of new energy infrastructure and close energy cooperation with the EU create the best conditions for security of supply and achieving energy and climate targets at the lowest cost.
   Overall, the "offensively integrated" scenario creates the most robust energy supply for Switzerland. In the "offensively integrated" scenario, the annual system costs are the lowest at around 24 billion CHF, and the dependence on electricity imports in winter is also relatively low at around 7 TWh (19% of winter half-year demand). In contrast, the costs in the "defensive-insulated" scenario amount to about 28 billion CHF and the import dependency for electricity is around 9 TWh (22% of the winter half-year demand).
4. Due to increased efficiency, a rebuilt energy system is less expensive than the status quo.
   This is especially true for the offensive scenarios. Replacing today's fossil fuel imports with electricity leads to reductions in annual system costs of 1 to 5 billion CHF, depending on the scenario. This significantly increases efficiency because electricity applications are more efficient than combustion processes. This does not yet take into account the expansion and conversion of the electricity grid.
5. Restructuring the energy system reduces Switzerland's overall energy import by a factor of 4 to 6.
   Today, the import dependency is 79% of a total primary energy demand of 259 TWh. In 2050, depending on the scenario, this import share drops to 30-42% of a total primary energy demand of 115-132 TWh, which reduces the absolute import dependency by a factor of 4 to 6. This is made possible by electrification, which results in higher system efficiency, increased efficiency on the demand side and the expansion of domestic energy production.
6. Switzerland will remain an importer of electricity.
   In winter, electricity must continue to be imported. The dependency on electricity imports in winter increases from 3 TWh today to 7 TWh in the "offensive-integrated" scenario; in the "defensive-isolated" scenario, 9 TWh of winter electricity must be imported. The import problem will temporarily worsen around the year 2040, because by then there will be no hydrogen infrastructure, most of Switzerland's nuclear power will already be off the grid, and electricity demand will increase due to progressive electrification.
7. Climate neutrality is only possible through comprehensive electrification. 
   In all four scenarios, climate neutrality requires the replacement of fossil fuels with electricity, especially in the transport and heating sectors. As a result, a minimization of domestic greenhouse gases from today's 35 million tons of CO₂ equivalents to 2.6 to 3.3 million tons can be achieved in all scenarios. To achieve net zero, additional measures involving the use of negative emission technologies are necessary, such as CO₂ capture in waste-to-energy plants or directly from the air (direct air capture). The additional costs for this amount to 3 to 3.5 billion CHF per year and are included in the system costs.
8. Hydropower remains the mainstay of the Swiss energy system. 
   It will dominate electricity generation in all scenarios with around 35 TWh. In the offensive scenarios, about 2 TWh of water storage can be added, which increases the winter security of the power system.
9. Alpine photovoltaic and wind power bring significant advantages for winter power supply.
   The generation from alpine PV open space plants amounts to about 2 TWh in 2050 in the offensive scenarios, the wind production amounts to about 3 TWh. Electricity imports are reduced by these plants. They thus make a substantial contribution to winter electricity supply.
10. Hydrogen can become an essential element of Switzerland's energy supply.
    The import of green hydrogen via the emerging European hydrogen infrastructure can become a mainstay of energy supply in winter, alongside hydropower and PV. In the "offensive-integrated" scenario, hydrogen-fueled gas-fired power plants supply about 13 TWh of electricity year-round, including 9 TWh in winter, covering about 20% of winter demand. The addition of new nuclear power plants such as Small Modular Reactors (SMR) is not economical under the condition of a strongly developed hydrogen infrastructure in the EU ("H₂-Backbone EU"), because the hydrogen-fueled gas power plants can cover the demand more flexibly and more cheaply.
11. Security of supply requires backup power plants and storage.
    The future energy system will be largely supplied by weather-dependent renewable production such as PV and wind power. In order to maintain security of supply under these conditions, backup power plants and storage facilities are necessary. The costs for this amount to about 1 billion CHF per year and are integrated in the system costs.
12. The restructuring of the energy system requires the conversion and expansion of the power grid.
    PV is massively expanded with a production of 18 TWh in the "offensive-integrated" scenario up to 28 TWh in the "defensive-insulated" scenario, mainly decentralized on roofs. Together with the electrification of transport and heat applications, this requires grid expansion and reconstruction, especially at the lower grid levels. The expansion of alpine PV also requires the construction of corresponding supply lines. This grid expansion is not yet considered in the present study and will be investigated in a further study by the VSE in 2023.

"With the Energy Future 2050, the industry is making a competent and scientifically sound contribution to the energy policy discussion and to the further development of our energy system," says VSE Director Michael Frank. The results show that achieving the energy and climate targets will by no means be a foregone conclusion, but will require major efforts. Business as usual is not an option. From the point of view of VSE, security of supply must be declared a national interest and hurdles must be removed so that security of supply and climate neutrality are possible by 2050.