Climate Change Impacts on Renewable Energy Across Western North America

---

Written by Aaron Studwell for Industrial Info Resources (Sugar Land, Texas)--A recently published study, Assessment of Climate Change Impacts on Renewable Energy Resources in Western North America, was conducted by Lawrence Livermore National Laboratory (LLNL) and commissioned by the U.S. Department of Energy (DOE). The research evaluates how projected climate changes may affect renewable energy resources across the Western Electricity Coordinating Council (WECC) region.

The WECC spans the western United States and southwestern Canada, covering a diverse mix of geographic and climatic conditions. Given the growing role of renewables in the electricity stack--particularly in regions with aggressive decarbonization targets like California--understanding how climate change might impact generation potential is critical for infrastructure planning and grid reliability.

LLNL researchers used a high-resolution global climate model with three-hourly data output across three distinct periods: historical (1979--2014), mid-century (2015--2050), and end-of-century (2062--2097). Generation capacity factors (CFs) were calculated using industry-standard methods that incorporate solar irradiance, air temperature, and wind speed extrapolated to turbine hub height. The study also defined "resource droughts" as days when capacity factors dropped below 50%, 25%, or 10% of the historical average for that calendar day--providing a means to assess seasonal and long-term variability in renewable availability.

Key findings indicate that mean solar capacity factors remain relatively stable through mid-century but decline modestly (~3%) by century's end. This drop is primarily due to increased cloud cover from higher evaporation and evapotranspiration, which reduces solar irradiance and photovoltaic output. Regional differences are significant: California and the Desert Southwest retain higher solar CFs but still show downward trends, while the Northwest (NWPP-NW and NWPP-NE) sees more pronounced seasonal reductions, especially in winter and spring.

Wind energy CFs are more variable, showing minor changes by mid-century but falling by an average of 7.5% by the end of the century across the WECC. Eastern portions of the region, including Alberta, Wyoming and New Mexico, currently possess greater wind potential, though most are expected to see declines--except for California, which shows a slight future increase.

Resource droughts are expected to intensify, particularly for wind. Historically (~1979--2014), wind droughts occurred around 22 days per year. By the end of the century, that number is projected to rise to 34 days annually. Solar droughts remain rare--under one per year in most areas--but still trend slightly upward.

Compound energy droughts, where both solar and wind CFs are low, remain relatively infrequent and are largely influenced by cloud cover. However, areas like NWPP-NE, where solar and wind contributions are more balanced, could face up to 17 compound drought days annually by the century's end.

The study concludes that while solar energy offers more consistent year-round output, wind's greater variability introduces challenges under changing climate conditions. Offshore wind--especially for California--emerges as a promising, more stable alternative, with higher CFs, minimal seasonal variation and only a ~3% projected decline. The findings underscore the importance of diversifying renewable generation, investing in energy storage and improving transmission infrastructure to maintain system reliability in the face of climate change.

Industrial Info Resources (IIR) is the leading provider of industrial market intelligence. Since 1983, IIR has provided comprehensive research, news and analysis on the industrial process, manufacturing and energy related industries. IIR's Global Market Intelligence (GMI) helps companies identify and pursue trends across multiple markets with access to real, qualified and validated plant and project opportunities. Across the world, IIR is tracking over 200,000 current and future projects worth $17.8 trillion (USD).