Anyone with good cleaning tips?

[Volusiano]

water hardness @21

Is that in grains per gallon, or is that the parts per million TDS (total dissolved solid) reading?

If it is grains per gallon, that's actually pretty hard. My city is about 20 grains per gallon.

If it's parts per million TDS reading, that's really low. Anything below 10 ppm TDS can probably be considered pure enough for cleaning purposes so you can get away without leaving stain spots behind when dried up. My TDS reading is around 700-800 ppm, regardless of whether this is coming straight from the city, or through my water softener.

[russ]

water hardness @21

You are lucky - underground here is all limestone and the water is so hard that it hurts when shower water hits you In the 500 to 600 range. Shower glass is spotted after a day.

[silversaver]

You're probably lucky to live in an area that doesn't have severe hard water, in which case the soft water is also not as hard.

water hardness @21

[Volusiano]

I think soft water is good enough. there's not water spot on my shower glass panels after 12 years (2nd water softener with Fleck 7000 valve)

You're probably lucky to live in an area that doesn't have severe hard water, in which case the soft water is also not as hard.

[silversaver]

I think soft water is good enough. there's not water spot on my shower glass panels after 12 years (2nd water softener with Fleck 7000 valve)

[Volusiano]

I should be able to reach all the panels on the roof with brass nozzle, but the water is coming from hard water garden hose. I'll try to connec to the hose that were through water softener from home, hope I have enough water pressure to reach the top of my roof from side of house. I don't really want to walk on the roof.....

Soft water from water softener may be better than hard water, but it's not the same as pure water. Water softeners exchange calcium and magnesium ions with sodium ions. It helps make detergent work better, and the water feel more soft and slippery on your skin. But when dried, spots still form on the glass. If the build-up is left over the years, spots can etch into the glass, making removal virtually impossible. I just spent hours cleaning my glass shower doors with a lot of elbow grease and a very strong cleaner caller DRIVEN Extreme Duty Glass Cleaner to get the mineral deposits off my shower doors' glass. After that experience, I swear I'll never put a water hose on the solar panels with anything but purified deionized DI water or RO water. Or let the rain take care of the cleaning.

[bcroe]

Washing Panels

All this talk of washing panels is scaring me. Sure single panel/micro converters don't generate
much potential. But my strings run 360 to 410 VDC. The only thing between that and everything
else is a thin layer of transparent insulation, and the hopefully waterproof wiring insulation. Just
one slip & fall into a panel could connect you to it. Water in the picture just multiplies the risk.

Mostly relying on rain for cleaning here in ILL. There is a LONG poled brush, but the whole length
of it is made out of insulating material, not metal. And no ladder involved. Bruce Roe

[silversaver]

very nice point. Just got myself a 22' Werner alum multi-position ladder from Home Depot that should take care the access to roof.

http://www.homedepot.com/p/Werner-22-ft-Aluminum-Telescoping-Multi-position-Ladder-300-lb-Load-Capacity-Type-IA-Duty-Rating-MT-22/100658955

I should be able to reach all the panels on the roof with brass nozzle, but the water is coming from hard water garden hose. I'll try to connec to the hose that were through water softener from home, hope I have enough water pressure to reach the top of my roof from side of house. I don't really want to walk on the roof.....

[frizzlefry]

I'll have to go find the research and analysis and was done on panel cleaning but I believe it was on the order of 1% or less difference on production numbers in the long run. I definitely don't plan on hiring someone to clean the panels as it just extends the ROI time frame but if there's excessive ashes, and no rain in sight, I may be inclined to hop on the roof with a hose. But so far from what I can tell, my max output hasn't changed much over the past couple of weeks. 34-36kWh per day for the high output days. Im not going to sweat even 100-200kWh difference in a year. That would be around $13-26/yr.

[Volusiano]

I spray mine down early AM, with plain water and jet stream nozzle. I do it while the overnight dew is still on them.

If you have hard water, the Mr Clean Car Wash Kit has a DI rinse cartridge, but not much pressure for distance.

Good point that cleaning should be done when the panels are still cool enough.

I used to use Mr Clean car wash kit to wash my car and rinse with the DI cartridge. I think they've discontinued selling it for a while now. You'd have to position the nozzle about an inch away from the surface because the spray is very weak in a vertical line (to conserve the DI life).

[Mike90250]

I spray mine down early AM, with plain water and jet stream nozzle. I do it while the overnight dew is still on them.

If you have hard water, the Mr Clean Car Wash Kit has a DI rinse cartridge, but not much pressure for distance.

[J.P.M.]

JPM- for what it's worth, here are my last four days since cleaning. You are right about yesterday being slightly less productive (it seemed to be a little foggier in the early AM that day and mild Santa Ana winds):

1/12 50.14
1/13 50.68
1/14 50.00
1/15 50.79

Further to all this cleaning stuff and not directly related - I JUST HAPPENED TO NOTICE:

1.) Bando's output seems to be a somewhat constant multiple of J.P.M.'s (mine), at least on clear days, something like 2.1 times J.P.M.'s, +/- a bit, at least for 3 consecutive, mostly clear days, with nearly identical irradiance.

2.) Bando has an 11.76 kW system, non Sunpower.
J.P.M. has a 5.32 kW system, Sunpower.
therefore,Bando's size is 2.21 times J.P.M.'s

3.) Bando has split array with 2 off south orientations.
J.P.M has 1 array 195 az., 18.5 deg. tilt.
Looks like both have some late afternoon winter shading.

4.) I'd suggest from the above if Bando's orientation were the same as J.P.M.'s, that Bando's output per installed kW might be about the same as J.P.M.'s.

Perhaps this is anecdotal, but it seems to lend some support to my opinion that any well made system using decent panels will probably perform close to or about as well as a Sunpower system, probably for a lot less money.

I maintain that Sunpower's good stuff and perhaps necessary if space constrained, but if not perhaps not as cost effective by far when compared to other quality systems that will likely last as long or longer than the owner will be in the house.

I'm just sayin' ya' know ??

[J.P.M.]

JPM- for what it's worth, here are my last four days since cleaning. You are right about yesterday being slightly less productive (it seemed to be a little foggier in the early AM that day and mild Santa Ana winds):

1/12 50.14
1/13 50.68
1/14 50.00
1/15 50.79

I'm still fooling w/ the data. Nothing firm yet. I'm comparing my 01/13 "dirty" array and 01/14 "cleaned" array. My output went from 23.88 kWhrs. to 24.19 kWhrs. day/day, 01/13 to 01/14/2014. But, the amount of horizontal irradiance as measured/recorded was nearly identical both days, a bit more on the 14th as measured on a horizontal surf., and a bit more on the array on the 14th when adjusted for the array surface orientation and slight changes day/day in the solar incidence angles by something like the increase in output. The 14th was warmer and windier than the 13th and those things need to be considered, one tending to decrease output, the other perhaps (probably ?) tending to increase output. The takeaway for now is that my cleaning experiment has resulted in a visually cleaner array, but I'm not sure I can quantify the benefits, if any, YET. The differences may be too small to quantify as they may be lost in the mud of the rest of the variables. Sometimes things like this have some similarities to separating fly crap from pepper. Stay tuned.

[bando]

JPM- for what it's worth, here are my last four days since cleaning. You are right about yesterday being slightly less productive (it seemed to be a little foggier in the early AM that day and mild Santa Ana winds):

1/12 50.14
1/13 50.68
1/14 50.00
1/15 50.79

[J.P.M.]

Mine used to be 20 minutes behind but recently, it been less than 10 minutes behind. I can count on one hand the times data's been "lost" over the last year and a half. Worst was when it went for half a day but all the data was recovered by the next day. I wish they'd update their Android app: it doesn't play well with Jelly Bean. It crashes if you try to load previous days' data. Works fine on Gingerbread which I still have on my phone.

It sent off another e-mail. Will report what happens, if anything. More of a PITA & sloppy than anything. Thanx for the info.