Embracing wind power in the solar PV-dominated Swiss landscape

The Swiss energy transition, characterized by the nuclear phase-out, relies mainly on the integration of solar photovoltaic (PV), mostly because wind technology faces challenges in local public acceptance. This study aims to analyse Swiss PV and wind generation data from 2020 to 2023 to assess their complementarity using statistical indicators and energy flow simulation. The results emphasize the time complementarity of both technologies through a strong correlation on monthly, daily and hourly intervals using Spearman’s correlation coefficient. Then, we introduce a new definition for a capacity factor as seen from the grid, relying on the point of connection capacity instead of the installation capacity. Finally, we explore a use case at the Swiss nuclear generation (i.e., 22.3 TWh) by combining PV generation (13.28 GW, or 11.186 TWh) and wind generation (6.38 GW, or 11.186 TWh) with storage (around 90 GWh). The results show that such a renewable system achieves a capacity factor of over 80 % with a storage capacity equivalent to 5.8 % of today’s available pumped hydro capacity. We also explore various storage options, such as stationary, pumped hydro and electric vehicles. These results shed light on how the inclusion of wind can enhance energy security across the year in Switzerland.