Three strategies for promoting green electricity in Switzerland

The Federal Act on a Secure Electricity Supply from Renewable Energy Sources, or Mantelerlass for short, which was amended by the Swiss parliament on September 29, 2023, is intended to accelerate the expansion of renewable energies. Its aim is to generate 35 terawatt hours (TWh) per year from green technologies (solar, wind, wood and biogas) by 2035. In comparison: in 2022, this figure was around 6 TWh. The new target would correspond to around half of Switzerland's expected electricity requirements for 2035. The other half would be covered by hydropower and imports. Switzerland would be supplied with electricity without nuclear energy and large fossil-fuel power plants.

 The Sweet Edge research consortium has analyzed various ways in which this goal can be achieved. Funded by the Sweet program (Swiss Energy research for the Energy Transition) of the Swiss Federal Office of Energy (SFOE), the consortium includes researchers from the Universities of Geneva and Bern, EPFL, ETH Zurich and other partners. They have developed three strategies for achieving the target of 35 TWh from green electricity by 2035. The study also included less ambitious targets (25 TWh/year with a mix of renewable energies or only with solar energy; 17 TWh with a mix). The technical, regional, economic and social impacts of the strategies were also carefully analyzed.

Strategy 1: Focus on diversity

The first strategy combines new technologies to ensure diversity and security of supply. To achieve the target of 35 TWh/year, it implies a mix of, for example, 25 TWh/year from photovoltaics, 8 TWh/year from biomass and waste and 2 TWh/year from wind. "This strategy includes discrete solar installations on facades and roofs and would be well received by the population. For the target of 35 TWh, solar installations can already be found throughout the country. Only in sunny Ticino and Valais would they be even more widespread," explains Evelina Trutnevyte, co-coordinator of Sweet Edge and Professor of Renewable Energy Systems at the University of Geneva. Wind farms would also be needed.

2nd strategy: focus on photovoltaic solar systems with batteries

This strategy relies on photovoltaic systems with storage batteries for self-consumption on private roofs. It requires a more active commitment from citizens, but has the advantage that certain less accepted technologies would be avoided. With the 35 TWh target, solar energy should supply 31 TWh/year, supplemented by 4 TWh/year from existing biomass and waste incineration plants. "Photovoltaic systems would be installed in the cantons of Bern, Zurich and Central Switzerland, where the density of suitable buildings is high and we are currently assuming a supportive funding policy. Graubünden and Valais would have to build many more plants, including on open spaces," explains Giovanni Sansavini, Professor of Reliability and Risk Engineering at ETH Zurich.

3. strategy: focus on productivity

This strategy focuses on optimizing the production of wind power and photovoltaic infrastructure, including rooftop and ground-mounted photovoltaics. It offers the advantage that plants would be concentrated in the most productive locations and investments in biomass and waste treatment plants would be avoided. To achieve 35 TWh/year, this option requires a mix of 30 TWh/year of photovoltaics and 5 TWh/year of wind energy. "Here, most of the photovoltaic solar energy would be concentrated in Alpine communities, particularly in Graubünden and Valais," explains Michael Lehning, co-coordinator of Sweet Edge and professor at EPFL. "This option would be the most efficient way of limiting winter imports."

Significant investments, but also many new jobs

The investment requirement from today to 2035 is between CHF 0.5 and 2.1 billion per year, depending on the strategy and target. The third strategy, "Productivity", would be the cheapest (CHF 1.4 billion per year for the 35 TWh/year target), as it requires the construction of the fewest plants. The first strategy ("diversity") would be the most expensive (CHF 1.7 billion) for the 35 TWh target, but the second cheapest for the less ambitious targets (17 and 25 TWh/year). As photovoltaics is the predominant energy source in all strategies, it would absorb at least 80% of the costs.

Depending on the strategy and target, the expansion of the required generation capacity could employ between 18,000 and 57,000 people full-time per year by 2035. Of these jobs, 33% could be in manufacturing, 62% in construction and installation, 4% in operation and maintenance and 1% in plant renewal. Photovoltaics with batteries would create the most jobs; the 35 TWh target would create 50,000 full-time jobs.

High acceptance of renewable energies and energy independence

In addition to the three strategies and their technical and economic assessment, the report uses survey data to document that concerns about energy security and supply, which have become more serious since the Russian attack on Ukraine, are accompanied by a strong desire for energy independence and domestic production of renewable energy. Nevertheless, according to Isabelle Stadelmann-Steffen from the University of Bern, "wind energy and ground-mounted photovoltaics - like nuclear energy - remain a controversial issue among the population". The Professor of Comparative Politics is responsible for a large population survey that was designed and conducted at the University of Bern and forms the basis for the acceptance analysis.

Realistic goals

The study shows that the four electricity generation targets are technically achievable without nuclear energy and large fossil-fuel power plants. The higher the target, the less electricity Switzerland has to import. With the target of 35 TWh/year, Switzerland can ensure an electricity supply that is almost entirely based on domestic production of renewable energies. Nevertheless, net electricity imports remain an important instrument for balancing supply and demand.

Source: www.unibe.ch