Key points are not available for this paper at this time.
As energy systems transform to rely on renewable energy and electrification, they encounter stronger year-to-year variability in energy supply and demand. However, most infrastructure planning is based on a single weather year, resulting in a lack of robustness. In this paper, we optimize energy infrastructure for a European energy system designed for net-zero CO₂ emissions in 62 different weather years. Subsequently, we fix the capacity layouts and simulate their operation in every weather year, to evaluate resource adequacy and CO₂ emissions abatement. We show that interannual weather variability causes variation of 10\% in total system cost. The most expensive capacity layout obtains the lowest net CO₂ emissions but not the highest resource adequacy. Instead, capacity layouts designed with years including compound weather events result in a more robust and cost-effective design. Deploying CO₂-emitting backup generation is a cost-effective robustness measure, which only increase CO₂ emissions marginally as the average CO₂ emissions remain less than 1\% of 1990 levels. Our findings highlight how extreme weather years drive investments in robustness measures, making them compatible with all weather conditions within six decades of historical weather data.
Gøtske et al. (Thu,) studied this question.