Why Rain Won’t Save Your Solar Panels This Pollen Season
If you’ve assumed a good rainstorm keeps your solar panels clean, the research says otherwise. A 2023 study by NREL, Duke University, and international university partners, published in the IEEE Journal of Photovoltaics, found that pollen buildup alone can cut panel efficiency by as much as 15% during peak pollen season. Even more surprising: unwashed panels lost roughly 10% of their annual production, and rain didn’t meaningfully help. Researchers found it took months for natural rainfall to restore performance, while a simple manual cleaning boosted output 5-11% almost immediately.
Why Does This Matter for Utah County Homeowners?
This hits close to home. We get heavy spring pollen from junipers, pines, and cottonwoods, followed by long, dry summers with almost no rain to rinse panels off naturally. Combine that with dust from fast-growing areas like Saratoga Springs, Eagle Mountain, Lehi, American Fork, and South Jordan, and panels here are working against the same conditions researchers studied, without the benefit of consistent rainfall to help.
What Does Lost Output Actually Cost You?
Every percentage point of lost output is money leaving your pocket and going straight to the power company. That’s less to put toward your family, your work, or whatever actually matters to you. Keeping your panels clean isn’t about chasing perfection, it’s about making sure the system you already paid for is doing its job.
How Do You Know If Your Panels Need Cleaning?
If it’s been a while since your panels were cleaned, now is a good time to check. A quick inspection can tell you whether you’re losing power to buildup you can’t easily see from the ground.
Sources: NREL, “NREL Research Finds Rain Not Enough To Wash Pollen From Solar Panels” (2023); IEEE Journal of Photovoltaics, December 2023.