EIP-ETH Collaboration: Rethinking future Swiss electricity supply

Since last year, Energy Infrastructure Partners and the Energy Science Center at ETH Zurich have signed a research collaboration. In this collaboration, EIP and ESC have developed scenarios for the future of Switzerland’s electricity system and assessed their impact on average electricity prices, price volatility and required investments for generation capacity. The collaboration has developed data-backed insights to illustrate potential pathways into a sustainable and secure energy future, while identifying potential risks and opportunities to the Swiss and European energy systems.

For this collaboration, we have defined a reference scenario, that presents the cost-optimal development of the Swiss power system. In this scenario, Switzerland relies primarily on rooftop PV and will achieve 35 GW of installed capacity in 2050. In general, new renewable energies such as rooftop PV, alpine PV, wind power, and biomass contribute 40 TWh to the modelled electricity supply in 2050. A similar contribution is made annually by hydropower. Summed up over the year, Switzerland produces the same amount of electricity as it consumes, indicating that a phase-out of nuclear power can be compensated for. While both importing and exporting of electricity happen throughout the year, Switzerland exports more than it imports in summer and imports more than it exports in winter in the reference scenario. Furthermore, the reference scenario was also run with an extended lifetime of Swiss nuclear power plants (NPP60/80).

In order to test how resilient the reference scenario is, we “shocked” it with three artificial extreme events. In the “Shock NTC30” scenario, we examined the possible impact of restrictions in net transfer capacities (NTCs) on the reference scenario. We did so as starting from 2025 onwards, all transmission system operators in EU member states must keep at least 70 percent of the relevant electricity grid capacity available for cross-border EU trade. In extreme cases, this could limit the net transfer capacities in the direction of Switzerland down to 30 percent. In the
“Shock Nuclear” scenario, we assumed that similar to the situation in 2022, 50 percent of the French nuclear power plants would be unavailable due to unplanned outages. In the “Shock Winter” scenario, Switzerland is forced to have a balanced electricity trade balance in winter, i.e., the same amount must be imported as exported.

In the results we see that despite reduced grid transfer capacities (Shock NTC30) and despite lower availability of the nuclear power plants in France (Shock Nuclear), Switzerland can still ensure electricity supply at all times. Above all, flexible hydropower is responsible for this, as it can be used in hours of scarce power generation or occupied grid capacities. The “Shock NTC30” scenario not only affects winter imports, but also summer exports, which are no longer possible to the extent that they were in the reference scenario. This leads to
significantly higher levels of PV curtailment.

The only scenario resulting in supply issues is the “Shock Winter” scenario. Forcing Switzerland to keep a balanced winter trade balance with the installed capacities of the reference scenario means that a significant share of domestic demand can no longer be met. Assuming capacities given by the “NPP60/80” scenario with an extended lifetime of nuclear power plants mitigates the supply issues created by this shock.

Two additional scenarios with additional (a) renewable or (b) higher hydrogen import availability were tested as well and resulted in less supply issues.

Reference scenario: eip_reference

Shock scenarios:
• Reduction of NTC to 30%: eip_shock_ntc30
• Lower availability of nuclear power in France: eip_shock_nuclear
• Balanced electricity trading in winter: eip_shock_winter

Prevention scenarios:
• High renewables potential and target: eip_prevention_renewables
• High hydrogen import availability: eip_prevention_gas

Further information on ETH-EIP collaboration:
• EIP press release: https://www.energy-infrastructure-partners.com/

Please note that in the Interactive Results Viewer the results are available only for the Energy Topic “Future electricity system”