Cleaning Solar Panels.

[Sunking]

All it take is water from a hose.

[Yaryman]

Yaryman. Could you update what the option you choose for cleaning those panels? I like to set quarterly panel clean if possible and try to learn until the first one due.

My long awaited decision on which cleaning method to use has finally been made.
After going to both Home Depot and Lowes to look at the options, I choose this squeegee product.
The plan is to just spray the panels and then squeegee them off so as to not get water spots.
I also went with a 16 foot extension product from Lowes. All the good extension poles have threads on the end.
The squeegee I selected wasn't meant for a threaded pole, so I had to place it on the top of the pole a screw that sucker down.

[solar_newbie]

Just do what you do for your glass windows... But to not gentle a little bit.

[J.P.M.]

My installer said to used Simple Green. My friend's installer said use water only. I don't know who's right.

Either one. I use dish soap and can't measure a change in efficiency whether I remove any water spots or not.

Most of solar PV is not rocket science. Cleaning panels is probably a lot like cleaning a launch pad - doesn't matter much the method as long as it's done on a somewhat regular basis with safety in mind. Just don't do it when the panels are hot and don't use a pressure washer. Shortly after sunup is perhaps best.

[8.4]

My installer said to used Simple Green. My friend's installer said use water only. I don't know who's right.

[woodtiger]

I am thinking about getting a pressure water so that I can get the water up to the second story roof, and make it 'rain.' Hopefully that will be enough to clean the panels.

[solar_newbie]

Wrong! Turning off the breaker just means that the panels are not supplying power to a useful load. There is still plenty of DC voltage on the panels. In the case of a grid tie system it could be as much as 400V DC, or even higher in unusual cases.
You can hope that the insulation on the wires is all good even after you soak it with water. And the water will not be a good conductor.
Some experiments have shown that even if you use salt water for conductivity you do not get a dangerous current path if the water stream has broken up into droplets by the time it hits the voltage source.
Do not try this with high voltage (power transmission lines) though.

You are right. DC voltage is still exist. For string inverter, it might go as high as 600-1000. However, for micro inverter, a single panel does not generate a lot of voltage.

[inetdog]

Why they kill you ? Just turn off the breaker, no electric will be in those panels right ?

Wrong! Turning off the breaker just means that the panels are not supplying power to a useful load. There is still plenty of DC voltage on the panels. In the case of a grid tie system it could be as much as 400V DC, or even higher in unusual cases.
You can hope that the insulation on the wires is all good even after you soak it with water. And the water will not be a good conductor.
Some experiments have shown that even if you use salt water for conductivity you do not get a dangerous current path if the water stream has broken up into droplets by the time it hits the voltage source.
Do not try this with high voltage (power transmission lines) though.

[solar_newbie]

Better yet, do it in the middle of the night, so they can't kill you. Bruce Roe

Why they kill you ? Just turn off the breaker, no electric will be in those panels right ?

[bcroe]

MR Clean Car Wash Kit has a DI rinse cartridge.

http://www.amazon.com/Mr-Clean-AutoDry-System-Starter/dp/B0006M56CE

Just hose the dirt off the panels, and then a rinse with the treated DI water.

Do it in the AM, when the panels are cool, and maybe pre-dampened from dew

Better yet, do it in the middle of the night, so they can't kill you. Bruce Roe

[Mike90250]

Where to get "soft water"? My tap water gives spot when washing my cars without wiping dry..

MR Clean Car Wash Kit has a DI rinse cartridge.

http://www.amazon.com/Mr-Clean-AutoDry-System-Starter/dp/B0006M56CE

Just hose the dirt off the panels, and then a rinse with the treated DI water.

Do it in the AM, when the panels are cool, and maybe pre-dampened from dew

[J.P.M.]

How often do we wash it if it doesn't rain in Socal?

I belive hosing them off every 4-6 weeks in the absence of rain will hold my performance degradation to about 3 % average or so. Your mileage will vary.

Also, as written, I can't measure a difference in performance due to water spots.

[solar_newbie]

water softner

It eats space in the garage next to the water heater . It is no go for me. The water is not that hard to be needed.

[silversaver]

Where to get "soft water"? My tap water gives spot when washing my cars without wiping dry..

water softner

[solar_newbie]

I just hose them down with soft water. no water spots. Maybe twice per year, that is really what you need to do besides the rain.

Where to get "soft water"? My tap water gives spot when washing my cars without wiping dry..