Research examines the effect of wildfire smoke on solar energy generation in the US
New findings from Colorado State University show that while wildfire smoke is increasingly blanketing much of the United States, its long-term impact on solar energy generation remains relatively minimal.
The study, published in Nature Communications, highlights that the reduction in average solar photovoltaic output due to wildfire smoke is generally modest, except in areas immediately surrounding active fires, where dense smoke plumes dominate. Despite recent intense wildfires, photovoltaic energy generation in the US has shown stability even during extreme events.
The CSU-led team used a mix of modeled and historical data from multiple wildfire seasons to assess baseline changes in solar energy resources associated with smoke. Postdoctoral fellow Kimberley Corwin, lead author of the paper, highlighted the importance of the findings as the country aims to expand solar energy’s contribution to its energy mix from 3% to 45%.
“Similar research has been done on specific events – especially around California’s larger fires. However, our work goes further and quantifies the effects over large time scales and geographic areas,” Corwin explains. “We show that there are significant impacts to solar energy resources near these fires, but that when smoke is transported further away, as we have recently seen in the Midwest and along the East Coast, this is much less of a concern in terms of long-lasting solar energy.” That has implications for where future facilities should be located for both long-term efficiency and grid stability.”
The research team focused on the effects of smoke on Global Horizontal Irradiance (GHI) – a measure of the total solar energy reaching the Earth’s surface, including both direct and scattered sunlight. GHI is especially relevant for planar photovoltaic systems, which dominate U.S. solar energy production.
To contextualize their findings, the team analyzed daily case studies from California’s highly active 2020 wildfire season and the quieter 2019 season. These were supplemented with monthly and annual aggregations of smoke impacts at the state, regional and national levels. Advanced satellite-based tools, such as the NOAA Hazard Mapping System Smoke product, helped the researchers measure impacts at different scales.
The study found that while smoke plumes from fires in California, Colorado and Oregon reached the East Coast in 2020, their effect on solar energy was largely transient. “While you see large reductions near active fires, that decreases rapidly with distance,” Corwin said.
“Significant losses are specific to the area immediately surrounding the fire, where the smoke column is denser and therefore blocks more light. Meanwhile, the impact of the large, transported plumes that can linger for days but are diluted is relatively modest compared to the average change in solar energy seen under other conditions, which is only about 5% and – in some places – even less than 2% compared to the average in years with little smoke.”
Improved battery storage could further mitigate short-term disruptions due to wildfires, Corwin added. Increased storage capacity would allow operators to rely on reserves instead of turning to natural gas to offset temporary power shortages near fire zones.
Corwin initiated this research as part of her doctoral studies in Atmospheric Sciences under Professor Emily Fischer. Her work was supported by funding from NASA, a CSU Food-Energy-Water Systems graduate program and the CSU SoGES GCRT grant. Co-authors include Jesse Burkhardt, Amit Munshi and Fischer of CSU.
Professor Fischer called Corwin’s work a “critical step in understanding the full implications of climate-driven increases in wildfire smoke.” She added: “This paper, and the other chapters of Kimberley’s thesis, have radically increased our understanding of how smoke affects the ground light needed for photosynthesis, solar energy generation, as well as the impact on other aspects of air quality.”
Research report:Availability of solar energy resources under extreme and historical wildfire smoke conditions
