Wildfire Smoke Reduces Solar Panel Output by 20%

A Washington homeowner recently reported a 20% decrease in solar panel energy output during periods of wildfire smoke, despite the sky appearing sunny. This phenomenon occurs because the microscopic particles in wildfire smoke scatter and absorb sunlight before it reaches the solar panels, diminishing their electricity generation capacity. Greg Field, owner of PGT Home Energy Solutions in Tempe, Arizona, explained that such reductions are not uncommon and can be mistaken for inverter malfunctions when homeowners observe a bright sky but declining production. This situation underscores how environmental factors like wildfire smoke can impact solar systems independently of traditional obstructions such as clouds, tree shadows, or panel debris.

Nicole Tomasin, chief commercial officer at Energy Access Innovations in Dallas, elaborated on the mechanism, stating that wildfire smoke creates a layer of microscopic particles suspended in the atmosphere. This layer interferes with sunlight, scattering and absorbing it before it can be utilized by the solar panels. Tomasin indicated that the 20% reduction observed by the Washington homeowner was a likely consequence of both airborne smoke particles and any soot or ash that may have settled directly on the panels. She further clarified that the visual brightness of the sky does not equate to the intensity of usable light reaching the panels, meaning a hazy-sunny appearance can still indicate significantly reduced solar energy potential.

The impact of wildfire smoke on solar energy production extends beyond the immediate presence of smoke in the air. Ash and soot particles can accumulate on the surface of solar panels, forming a physical barrier that impedes light absorption. This accumulation can lead to prolonged periods of reduced energy output. Tomasin noted that air quality in a region might improve and clear of smoke days or even weeks before the solar panels are free of accumulated particulate matter. Consequently, solar production can remain depressed long after the visible smoke has dissipated, requiring external cleaning or rainfall to restore optimal performance. This highlights a critical, often overlooked, vulnerability of solar energy systems in areas prone to wildfires, necessitating proactive monitoring and maintenance strategies for homeowners and solar energy providers alike.

This issue affects homeowners relying on solar power for their energy needs, potentially increasing their reliance on grid electricity and associated costs during smoke events. For the solar industry, it points to the need for developing more resilient systems or mitigation strategies, such as advanced panel cleaning technologies or predictive models that account for environmental particulate matter. The incident serves as a reminder that the efficiency of solar energy generation is susceptible to a wider range of atmospheric conditions than previously assumed, particularly in regions experiencing increased wildfire activity. Understanding these impacts is crucial for accurate energy production forecasting and for ensuring the reliability of renewable energy sources.