Is Solar Panel Cleaning Worth It in Las Vegas?
Short answer: sometimes. Light, even desert dust on a tilted panel usually costs less than a cleaning, and UNLV research found washing gave only a very small gain on campus panels. Cleaning is worth it when your glass has bird droppings, mud streaks, mineral film or construction dust, or when your monitoring app shows a clear drop against the same month last year.
We clean solar panels for a living, so you might expect us to say always. We would rather you pay for a cleaning when it actually helps.
What the research says
| Study or test | Where | What it found |
|---|---|---|
| UNLV thesis on campus solar plants (Tanaka) | Las Vegas | Washing gave a very small efficiency and power gain. It took at least 0.2 inches of rain to partly restore clean output. |
| UNLV thesis on washing water quality (Boeing) | Las Vegas | About a 1.88% efficiency loss from dust, at a site covered in compacted soil and rock to keep dust down. Distilled water cleaned best. |
| Review of dust on solar panels (Yakubu et al.) | Global | Losses from about 10% in mild conditions to over 40% in arid regions, depending on dust type, wind and rain. |
| UC San Diego study (Kleissl) | San Diego | Homeowners would not get their money back paying to wash rooftop panels there. |
| Jinko Solar engineer | Coastal Southern California | Cleaning gave about a 3% to 5% gain. |
| Footprint Hero side-by-side test | US home test | Gains of 10.8% and 13.4% on the dirtiest panels, well below the 20% to 25% often claimed in ads. |
The pattern is clear: how much you gain depends on what is on the glass. Thin dust costs little. Heavy soiling in dry, dusty places can cost a lot. Las Vegas homes can land at either end, which is why we check before we sell.
When cleaning is worth it
- Bird droppings on any panel. They fully shade the cells underneath and can cut a whole panel’s output by about a third.
- Pigeons nesting under the array
- Mud streaks after a dust storm or a short monsoon shower
- White mineral film from someone hosing the panels with tap water
- Construction dust from a build site next door
- A clear drop in your app versus the same month last year, with no new shade
- A low-tilt or flat array, where rain cannot run off
When you can skip it
- A thin, even layer of dust and nothing else
- Output on clear days matches the same month last year
- The panels were cleaned in the last six months
- Someone at the door says every house needs three cleanings a year, without looking at your numbers
Do the math for your own roof
You need three numbers: your yearly production in kWh (it is in your monitoring app or NV Energy bill), the share you are losing to dirt, and what a kWh is worth to you.
- Find your loss. Compare a clear, sunny day this month with a clear day in the same month last year. Take off about half a percent for normal panel aging. What is left, if your roof has no new shade, is roughly your soiling loss.
- Turn it into kWh. Yearly production × loss %. A system making 12,000 kWh that loses 5% gives up 600 kWh.
- Turn it into dollars. New NV Energy customers get net-metering credit at 75% of the retail rate, about 10.7 cents per kWh. 600 kWh × $0.107 is about $64 a year.
- Compare with the price. Most Las Vegas cleanings run about $100 to $250. If a year of losses is less than the cleaning, wait, unless there are droppings.
| Yearly production | 2% loss | 5% loss | 10% loss |
|---|---|---|---|
| 8,000 kWh | About $17 | About $43 | About $86 |
| 12,000 kWh | About $26 | About $64 | About $128 |
| 16,000 kWh | About $34 | About $86 | About $171 |
Values use 10.7 cents per kWh. Older systems on earlier NV Energy net-metering tiers may get a higher credit, which makes cleaning pay off sooner.
Why the “20 to 40% more power” claims are misleading
Big percentages come from panels that were badly soiled, or from before-and-after readings taken at different times of day. One widely shared Reddit post showed output jump from 2.46 kW to 3.26 kW after a wash, but the readings were an hour apart in the morning, when the sun is climbing fast. A fair test compares the same time of day, on similar clear days.
Solar installers push back on cleaning for the same reason: on a typical roof, a yearly wash often costs more than the power it brings back. That holds for light dust. It does not hold for droppings, mud or mineral film, and that is where we focus.
Worth it FAQs
Is solar panel cleaning a scam?
No, but it is often oversold. Cleaning genuinely helps when panels have droppings, mud or mineral film. Selling the same three cleanings a year to every house, without checking production, is where it turns into an upsell.
Doesn’t Las Vegas wind clean the panels?
Wind moves loose dust around but does not remove droppings, mud or mineral spots, and it brings new dust with it. Dust storms usually leave panels dirtier, not cleaner.
Does rain clean solar panels in Las Vegas?
Not much. Las Vegas gets around 4 inches of rain a year, mostly in short monsoon storms, and UNLV found it took at least 0.2 inches to partly restore output. Light rain often leaves mud streaks, and droppings stay put.
How much more power will I get after a cleaning?
It depends on how dirty the panels were. Light dust may give back a few percent. Heavily soiled panels in a side-by-side home test gained about 11% to 13%. Check your own app on a clear day at the same time before and after.
Can not cleaning damage my panels?
Dust itself does not hurt panels. Bird droppings can, because they create hot spots on the cells underneath, and nesting debris builds up around wiring. That is why droppings are a reason to clean even when the power loss looks small.
Not sure? Ask us first
Send us your panel count and what your app shows. If a cleaning will not pay for itself, we will tell you. See typical Las Vegas cleaning prices or our residential cleaning service.
Sources: UNLV (Tanaka), UNLV (Boeing), Yakubu et al. review, Solar.com on UC San Diego study, Footprint Hero test, The Cool Down on the Reddit post, Nevada net metering 2026. Updated October 2026.