Market and Operational Weather Risks in the Western U.S. Power Grid

The Western U.S. is a compelling test case for whether systems experiencing increased severe weather from climate change can quickly decarbonize. Western power system operators must manage exposure to more intense and widespread droughts and heat waves, which reduce the availability of hydropower and increase electricity demand. At the same time, over 60% of the Wests electricity consumption occurs in the three coastal states, which have all pledged to decarbonize their electricity supplies by 2050 or earlier, largely by increasing reliance on variable renewable energy (wind and solar). Challenges presented by the joint effects of decarbonization and extreme weather have already materialized in the West, including the 2020 rolling blackouts in California, caused by extreme heat (surging afternoon and evening demand) and system operators struggles to account for normal, evening declines in solar. Other looming issues for a potential future zero-carbon Western grid are shifting hydrological patterns (more winter precipitation falling as rain, and earlier spring snowmelt), which could exacerbate challenges related to seasonal variability in renewable energy production. This talk will feature results from several completed studies that seek to address current and future weather risks in the Western grid, focusing on the potential for reliability impacts and market price shocks. We will discuss modelling challenges in capturing simultaneous, multivariate extremes across large geographical extents; computational experiments designed to produce probabilistic measures of system performance; the need for integrating short- and long-term uncertainties, including climate and technology adoption pathways; and open questions regarding the representation of institutions. We will close by highlighting current efforts to address some of these modelling challenges.