Arrays around Centennial Golf Course sit in a dust corridor. Farm ground west of town, gravel overflow lots at Ford Idaho Center, and steady traffic off I-84 Exit 38 all put fine grit in the air. Course irrigation adds hard-water mist to the low edges of arrays on fairway-backing lots.
Soiling here is not one thing. From roughly June through October you get agricultural dust drifting in off the farm ground west and south of Nampa, heaviest during cutting and harvest, and it is a fine silt that settles rather than blows off. Layered on that is grit from the gravel overflow lots and event traffic around Ford Idaho Center and the Garrity Boulevard interchange, which spikes on event weekends instead of building evenly. In spring, cottonwood and grass pollen from the course turf and the mature trees on these older lots sticks to glass that already has a dust film on it. None of it is dramatic on any single day. It stacks, quietly, and by August the array is producing noticeably less than it did in May without anything having broken.
Dust rinses. Hard water does not. Nampa city water tests as hard as about 7 grains per gallon, and any sprinkler head that reaches the low edge of a ground mount, a shop-roof array, or a low-pitch garage array leaves mineral deposits every time it cycles. Those dry into a scale film that a hose makes worse, because you are rinsing hard water onto hard water. On fairway-backing lots you can also catch mist off the course's own irrigation on windy mornings, April through October. If your array's bottom row looks hazier than the top row, that is almost always sprinkler reach, not dust. We clean with 100% pure deionized water and no soap, so the minerals lift and nothing is left behind to attract the next round of dust.
The houses ringing this course are mostly 1990s and 2000s builder construction with composition shingle roofs at fairly shallow pitch, and that matters more than people expect. On a steep roof, rain sheets off and takes some of the dust with it. On a 4:12 or 5:12 the water crawls, and a summer thunderstorm just turns the silt into a muddy film that dries in place. Retrofit arrays on these homes usually went on whatever plane had room, so plenty of them are west-facing over a garage rather than clean south, which means they collect afternoon dust and produce less to begin with. Flush-mounted panels with a shallow tilt also drain slowly along the bottom rail, and that lower edge is where the dirt line and the water spotting both show up first.
Cleaning recovers output lost to soiling. It does nothing for anything else, and it is worth knowing which one you have before booking. Pull up your monitoring app and look at the shape of the loss. A gradual slide over dusty weeks that recovers after a hard rain is soiling, and washing helps. A sudden drop, or one string or one panel down while the rest are fine, is hardware, and you want your installer, not us. A clean morning curve with a bite taken out of it mid-afternoon is shading, usually the mature trees that have grown in around these older lots over twenty-plus years, and no amount of washing moves a shadow. Panels also lose roughly half a percent a year to normal degradation. That is permanent, and clean glass will not bring it back.
Solar panel cleaning is quoted per array, since a six-panel garage retrofit and a twenty-four-panel south roof are not the same job. We work with pure deionized water and a soft brush on a fed pole, from the ground wherever the reach allows. No soap, no detergent, no wax. Soap leaves a film, and a film on a panel is a dust magnet that has you calling again in six weeks. No pressure washer either, which risks frame seals and junction boxes on older arrays. We stay off the panels themselves, and on these older comp-shingle roofs we only walk what is safe to walk, especially in July heat. Same-day and next-day slots, fully insured, locally owned, 4.9 stars across 115+ Google reviews, and every visit carries our 7-Day Rain Guarantee. Monthly and Quarterly memberships are available with no contract if you want the array bundled with your window work.
Free, no-obligation estimate in under 60 seconds.
Get My Free EstimateCentennial Golf Course area →
Centennial Golf Course area →
Centennial Golf Course area →
Centennial Golf Course area →
Centennial Golf Course area →
Centennial Golf Course area →
Centennial Golf Course area →
Nampa →
Still wondering about something? Call or text us at (208) 453-6760.
In a dry Nampa summer with farm dust in the air, soiling losses of a few percent up to the low teens are realistic on a shallow-pitch array that has not seen rain in weeks. Steeper arrays that get rinsed regularly lose less. The honest answer is to check your monitoring app against last spring. If the loss is small and your array is small, cleaning may not pencil out, and we will tell you that.
No. That is one of the most common calls we get around this course, because the landscaping on these 1990s and 2000s lots is now twenty to thirty years mature. If your production drops off at a predictable time of day and recovers, that is a shadow, not dirt. Cleaning changes nothing. Trimming or a panel-level optimizer conversation with your installer is the fix.
Yes, and it is the one worth fixing at the source. Nampa water is hard enough that repeated overspray builds a mineral scale that dulls the glass in a band along the bottom rail. We can lift it with deionized water, but if the head keeps cycling onto the array it comes right back. Adjust or swap that head, then have the panels cleaned once, and it stays clean.
Once a year is enough for most homes here, timed for late summer after harvest dust and before the shorter days when every hour of production counts. Go to twice a year if you are close to open farm ground, backing an active construction phase, or if a sprinkler reaches the array. Do not clean on a schedule for its own sake. Watch your production numbers and clean when they tell you to.
We work from the ground with a fed pole whenever the reach allows, which covers most single-story and garage arrays here. When we do have to be on the roof, we walk only what is safe on 1990s and 2000s composition shingle, which gets soft and scuffs easily in July heat, and we never step on the panels. If a roof is too brittle or too steep to work safely, we will say so instead of risking it.
No on both. Soap leaves a residue that holds dust and puts you back where you started within a couple of months, which is why we use 100% pure deionized water and nothing else. Pressure risks driving water past frame seals and into junction boxes, and on an older array that is an expensive way to save fifteen minutes. Slower and dry is the right trade here.
Free estimate in 60 seconds. Same-day and next-day slots available.
Get Free Estimate Now