Common Questions

Clean panels capture more sunlight. According to NREL's PV Fleet Performance Data Initiative, soiling losses range from 2–15% annually across U.S. solar systems, with some sites losing significantly more during pollen-heavy seasons. Customers typically see improved production within 24 hours of service.NREL Soiling Losses Report (2024)

Check your monitoring app for declining production trends compared to the same period last year. Visible haze, bird droppings, or debris are obvious signs. In Wisconsin, most systems need cleaning after winter road salt season and again after spring pollen. NREL research specifically found that rainfall alone doesn't recover pollen losses — mechanical cleaning is required. (For a full breakdown of 8 region-specific signs, see our When to Clean guide linked in the footer.)NREL: Rain Not Enough to Wash Pollen (2023)

No — this is the most common myth in solar. Research from NREL and the German Aerospace Center (DLR) confirms that rain only partially removes loose dust. It cannot remove pollen, bird droppings, mineral deposits, or agricultural residue. Light rain actually makes panels dirtier by redistributing particles and leaving mineral residue as it evaporates. Professional cleaning with deionized water is the most effective way to recover lost output.Renewable Energy World: NREL Pollen Study

For most systems, yes. NREL data shows median soiling losses of 2–3% for typical U.S. sites, but spring pollen and agricultural areas can push losses above 15%. A Princeton University study found that combining regular cleaning with environmental monitoring significantly boosts long-term PV output. Beyond production recovery, professional inspections catch issues — cracked cells, hot spots, pest damage — before they become costly repairs.Princeton: Panel Cleaning & Air Quality (2021)

We strongly advise against it. Tap water contains calcium and magnesium that leave white mineral deposits, which actually reduce light transmission further. Wisconsin has notoriously hard water (18–20 grains per gallon in the Madison area). Beyond water quality, climbing on your roof without fall protection is the leading cause of injury for homeowners. Our deionized water system eliminates 100% of mineral content, and our soft rotary brushes are specifically engineered for solar glass coatings.Madison Metropolitan Sewerage District: Water Hardness

Yes — and it's more common than most homeowners realize. The standard ISO HO-3 policy (the dominant form used by most U.S. insurers, including State Farm, Allstate, and Liberty Mutual) explicitly excludes loss caused by "wear and tear, deterioration, inherent vice, and neglect." Cleaning is considered routine maintenance, and the Insurance Information Institute notes that insurers may deny claims if damage results from neglected upkeep. Every state's insurance code also includes a "duty to mitigate" clause requiring you to take reasonable steps to prevent damage. A simple paper trail of professional cleanings — with timestamped before-and-after photos — protects you. See our Warranty Protection page for the full breakdown with citations.Insurance Information Institute: HO-3 Homeowners Sample Policy (PDF)

Natural panel degradation averages about 0.5% per year according to NREL's review of over 1,900 systems — meaning panels retain roughly 87–90% output after 25 years. That's a slow, gradual decline. If you're seeing a sudden 10–25% drop, it's almost certainly soiling, not aging. Soiling losses are fully recoverable with professional cleaning; degradation is not. The key difference: degradation happens over decades, soiling happens over weeks.NREL Photovoltaic Degradation Rates Review

Wisconsin subjects panels to a relentless four-season cycle. Winter brings road salt spray and deicing chemicals that drift onto rooftops. Spring pollen from oak, birch, and maple creates a sticky biofilm that rain cannot remove — NREL research specifically identified pollen as a persistent soiling agent. Summer adds agricultural dust and fertilizer drift. And hard water throughout the region (18–20 grains) means even well-intentioned garden-hose cleaning leaves damaging mineral deposits.NREL: Addressing Soiling on PV Modules

Late April through early May — after pollen peaks and salt residue has set — is the most impactful time. This helps panels perform strongly heading into the high-production summer months (May–August), when they generate the majority of your annual energy. An optional fall cleaning before shorter daylight hours can further optimize annual output.

Yes. Agricultural environments experience 2–3x higher dust accumulation than urban areas. Crop harvesting, fertilizer application, unpaved roads, and equipment activity all generate airborne particulates. A study from the IEA Photovoltaic Power Systems Programme found that soiling rates in agricultural zones can exceed 15% annually without intervention.IEA PVPS: Soiling Losses Impact Report

Most residential systems (15–30 panels) take 30–60 minutes. Larger commercial installations may take 2–3 hours depending on access and system size. We work efficiently while maintaining quality standards, and you don't need to be home.

We serve Southern Wisconsin — the 15-county Wisconsin DHS Southern Region anchored on Madison. That covers Adams, Columbia, Crawford, Dane, Dodge, Grant, Green, Iowa, Juneau, Lafayette, Marquette, Richland, Rock, Sauk, and Vernon counties (Madison, Fitchburg, Sun Prairie, Middleton, Verona, Waunakee, DeForest, Oregon, Stoughton, Mount Horeb, Janesville, Beloit, Monroe, New Glarus, Brodhead, Baraboo, Reedsburg, Portage, Lodi, Dodgeville, Mineral Point, Spring Green, and surrounding cities). Don't see your city? Request a quote anyway — chances are we can help.

We use soft rotary brush heads, biodegradable soap, and 100% deionized water — no pressure washing, no harsh chemicals. This is the exact method recommended by manufacturers including Tesla, SunPower, LG, and LONGi. Our process will not void your warranty, and deionized water leaves zero mineral residue.

Yes — try our free instant calculator at /pricing (Residential tab). Enter your panel count and home style and you'll see your price in seconds, no contact info required. Residential pricing is $7/panel for 1-story homes ($150 minimum) or $9/panel for 2-story homes ($215 minimum) — we charge whichever is greater, never both. Commercial, agricultural, and government sites are custom-bid — tell Marquis a little about your facility on the Commercial tab and he'll personally email you a written bid with a firm price within 24 hours. No call-around games.

Residential cleaning is $7 per panel for 1-story homes with a $150 minimum, or $9 per panel for 2-story homes with a $215 minimum — we charge whichever is greater, never both. So a 20-panel 1-story home is $150 (the minimum wins) and a 30-panel 2-story home is $270 (30 × $9 = $270, above the $215 minimum). Standard mileage is included on the final quote. For an instant estimate with no contact info required, use the live calculator on our /pricing page. Commercial, agricultural, and government sites are custom-bid within 24 hours — every facility is different.

Nothing bad. Rain that falls within a day or two of a Solar Alchemist cleaning is just water on already-clean glass — the deionized rinse leaves no mineral residue for the rain to redistribute. If you ever notice streaks, spots, or unusual debris within 48 hours of our visit, text Marquis and we'll schedule a complimentary touch-up. We stand behind our workmanship — the glass will look right when we leave and hold up against normal weather.

Yes. We service residential rooftops, commercial buildings, agricultural operations, and government facilities across Southern Wisconsin. Our most recent state-government job was cleaning the Wisconsin State Capitol's solar array — installed in 2009 and never cleaned in 16 years, with a measured +16.7% production lift after one visit. We're set up for procurement: EIN and W-9 available on request, Certificate of Insurance naming your entity as additional insured, itemized written scopes-of-work, and timestamped service documentation suited for O&M records, performance bonds, and PPA contracts.

Yes. For commercial facilities, agricultural operations, property managers, and government clients with multi-site portfolios, we offer scheduled annual or bi-annual maintenance contracts with locked-in pricing, fixed cleaning windows, and unified documentation across every site. This is what most insurance carriers and PPA contracts now require as proof of ongoing maintenance. Tell us about your portfolio on the Commercial tab and Marquis will personally structure a custom bid sized to your operation within 24 hours.

Every job includes: a written itemized scope-of-work signed before service begins, a Certificate of Insurance naming the property owner or contracting entity as additional insured, timestamped before-and-after photos of each panel section, irradiance readings where applicable, and a final service log with date, technician, panel count, and method. These records meet the documentation requirements of most commercial property insurance carriers, PPA O&M clauses, and government procurement standards.