Solar panels are powering through US West wildfire smoke: Study

The wildfire smoke that often wafts across the U.S. West may only be causing minimal disturbance to the output of photovoltaic solar panels, a new study has found.

Smoke-linked losses of photovoltaic resources remain modest outside of the areas immediately surrounding active blazes, where plumes are denser, according to the study, published in Nature Communications.

Meanwhile, power produced by panels nationwide has remained relatively stable — even during extreme fire seasons, the study authors observed.

While previous studies have focused on the connection between specific wildfire events and solar panel function, the researchers sought to understand any impacts from smoke cover spreading across the U.S.

“We show there are significant impacts to solar power resources near these fires," first author Kimberley Corwin said in a statement, referring to the immediate areas of the big blazes.

"When smoke is transported farther away, as we have seen in the Midwest and along the East Coast recently, it presents much less of a concern in terms of prolonged solar losses," added Corwin, a postdoctoral fellow at Colorado State University.

That knowledge, she explained, could have major implications as the U.S. looks to ramp up the contributions of solar power in its overall energy portfolio and strategizes where to place future facilities.

Corwin and her colleagues specifically looked at the impact of wildfire smoke on irradiance, or the amount of solar light that makes its way to the surface of a panel. In general, solar power generation can be hampered by many factors, including cloud cover, smoke and other sources of air pollution.

The scientists focused on a particular type of irradiance — which includes both direct sunlight and sunlight scattered by the atmosphere — and which is most relevant to prevalent flat-plate photovoltaic systems.

During the very active 2020 wildfire season, smoke burning in California, Colorado and Oregon ultimately covered large swaths of the East Coast. Yet although the plumes brought some short-term production losses, they only caused modest long-term effects, according to the study.

“While you do see large reductions close to active fires, that drops off quickly with distance," Corwin said. "Substantial losses are specific to the area directly around the fire where the smoke column is denser and therefore blocks more of the light.”

Output levels for fire-adjacent California PV plants in 2020 plunged by about 11-17 percent in comparison to averages of low-smoke years, while those near blazes in Greece in 2021 dropped by 10-20 percent, per the study.

The massive, travelling smoke plumes do linger in the skies for days, but they do so in a dilute form and in a way comparable to other weather variabilities, according to Corwin.

"Even during extreme wildfire seasons with heavy smoke, as seen in 2020, we project little change in average PV resource availability, except in areas with optically thick, fresh, local smoke plumes," the authors stated.

The decreases caused by transported smoke typically stayed below 5 percent and in some areas, less than 2 percent, Corwin noted.

To adapt to those short-term impacts, however, Corwin suggested that battery storage could help minimize short-term power impacts. By switching to battery reserves, operators would be able to avoid relying on fossil fuels to make up for deficits, she added.