Because they don't clean them selves. Forget about the hippie "no water" solar panel cleaning bullshit. It don't work. Do you want scratched solar panels? Because that's how you get scratched solar panels. The one way to clean them is the "car wash method" where you use soap plus water and some manual scrubbing... ain't no body got time for that... I use my pressure washer. It's a little generac 2.5gpm pump on a horizontal 208cc Honda clone. But it's getting old, had it since 2015 or so. I'm going to haul the old one to the tractor auction and sell it before it blows up and it's worthless. I have an old Honda gx390 that ran for a while with effectively no air filter, so it burns oil. Well I'm rebuilding it. The bore has some taper and oil rings were worn down to nothing. I guess dirt likes to get caught in the oil rings and wear them out. It burned oil like crazy. Because of no air filter and sum dumb ass put the biggest carburetor jet they could find in it so the oil and dirt were getting washed down the cylinder by ridiculous amounts gasoline. That results in an engine you fill up with oil run it and the low oil shutdown kicks the engine off after 45 minutes to an hour. Rebuilding this the be about a 48 state legal de-CARB'ed engine. With a new std bore block, std piston, new rod, new tappets, 0.01 over bore rings I'm using as file fit rings, ultra thin head gasket that will bump compression about a half number, I'll test timing advance, retard and put a retro style adjustable carb on it. The higher compression, possibly advanced timing, and adjustable carburetor will give more power, use less fuel and make a tiny bit more NOx than the 50 state legal version. I still have my new pandemic 4gpm, 4,000psi pressure washer pump still sitting in the box. Been sitting there for about 2 years, need to so someone with it already.
In the winter, my panels are nearly vertical. So snow and ice slides off on its own. In the summer months, my panels are near diagonal. I think the rain keeps them plenty clean.
LOL Have a niece/nephew in UT that had a gig at the local 'solar farm' Panel Technicians. John Deere Gator pulling a 250 gal tank. Pressure washer in back of Gator. Water is 'deionized(?WTF) and soft, that is no alkali. Run up and down the alleyways pressure washing the panels. Squeege off the bird shit. Reach the end of the farm after about a week. Start all over. Paid for college..... How big? pretty big.
Mine lay flat year round so they need regular attention because I get a lot of wind and birds daily. All I've ever used is an automotive squidge and sponge, and don't get any scratching. Good enough for car windows good enough for solar.
Its that film they get on them that you really can't see that builds up over time and starts chipping away at their efficiency that gets you. Guess it is pollen and airborne environmental pollutants that make up the film. Soap, water and soft window brush gets it off and worth doing at least every other year if not every spring or fall.
Car wash soap with a dash of Purple Power and white vinegar, long handled car wash brush, and pressure washer to rinse. Gets my tiny solar farm squeaky clean. Pollen is murder here, and if it gets hardened onto something it is almost impossible to get off. I had to use 0000 steel wool once, so now I just wash them when I wash the car.
I wash mine when i'm in the end of the rain system April or around , need to have all the polon soft , I use Bleach / dishwashing soap , MK and mix a real straight heavy soap that the pressure washer can spray out , I need a man lift to get up to my panels . 3 days Im done 5 sets of 45 panels Sloth
Got the new engine mostly put back together. The old worn out engine had 72psi of compression cold and 72psi warm.
Also I can't reach a third of them, because they are clumped together. I used a "F188" Honda knockoff piston. Now my cold never fired compression is about 120psi. Everything I can find on the internet says compression on a stock engine is about 100 to 105 psi close to sea level. I'm at 4,000ft with about 12% less air. It runs great it started on the first pull. I put a carb with adjustable air bleed, it came with a big old main jet, unmarked of course, definitely least a 1mm or #100, probably a 104, ran rich, smoked on throttle up. First test I did was swap in a #69, it didn't want to stay running and I expected that. Next step up because it wouldn't run I skipped over all of my 70s jets and went with a #86, it would run, but didn't want to throttle up quicly still too lean and I think I got some engine knock because of it running lean and having such high compression. I thought I had a 90 and 92 but didn't find them, so I stuck in a 95 and ordered another 100, 97, 95, 92 and 90 set.
Lets say you live on the NE and WYO border. And have a big-ass solar farm. And you get hailstones hitting between 100 and 150 MPH. Result, no panels to wash. 'baseball' sized hail. Baseball-Sized Hail Smashing Into Panels At 150 MPH Destroys Scottsbluff Solar Farm | Your Wyoming News Source (cowboystatedaily.com) Bet you can get a good deal on salvaged (whole) panels.....
Until the hail takes them you got to keep them clean. Looks like 10% of the panels survived. We don't get many broke panels per hail storm around here. All but one golf ball size or lager hail storm from the last 15 years came from the north. Panels are normally south facing. So the hail hits at an acute angle and usually doesn't damage them.
If you have like 7kw or more of panels to clean, don't even mess with a consumer grade pressure washer. If you have a few panels or a few kw of panels that are easy to reach "car wash" them or use an electric pressure washer. A dozen panels or more that are easy to get to, a consumer grade one will probably be fine. I have 30 big panels all clumped together so a 4gpm pump with a larger engine is the way to go.
I have advanced the timing, it ran even better had more power. Then I installed a go-kart intake plus air filter and it allows so much more air into the carb it stalls the engine on throttle up every time. Have to put a bigger main jet in the carb. Like a lot bigger. I tried running an #86 on the stock intake and it didn't want to throttle up, had to put in a #98 before it would run okay, setteled on a #100. I'll probably try a #102 today.
Put a #102 jet in my gx390 pressure washer, niet. Still needed more. I had to go to a #105 to get it just to throttle up, still wanted to die, im pretty sure it's still a bit lean. I have a #107 I need to try.
Ran up the gx390 powered 4gpm pressure washer to clean off the solar panels. It was a nice day in the low 80s, perfect day for cleaning solar panels. I bought an oil dipstick temperature gauge. I knew the gx390 runs hot running 4,000rpm and wide open throttle for an hour at a time, well now I know how hot. The temperature of the oil peaked at 260F. On a 100F day that could easily be 280F. Yeah dats hot. Too hot. I should probably investigate ways to cool down the oil a bit and filter it too, might as well just for the hell of it.
One might attach a heatsink at the bottom of the crank case. For added cooling a computer fan might be employed against the heatsink.
The under side of the engine is irregular shaped and has a gap in the fan shroud to allow for some cooling air to it. I probably have a liquid to liquid heat exchanger around some where and could run the oil as cool as I want it, assuming I have a way to circulate the oil.
