Anyone with good cleaning tips?

[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.

[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 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]

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

[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.

[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.

[silversaver]

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 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.

gpg, it is normal in OC. That's also why we need water softener. Be sure you use good ones with high flow distributor and 10% crosslink.

[Volusiano]

gpg, it is normal in OC. That's also why we need water softener. Be sure you use good ones with high flow distributor and 10% crosslink.

I'm not sure what high flow distributor and 10% crosslink means for a water softener. Mine is a pretty generic Sears water softener. It seems to do the job OK. The softened water feels soft and slippery on the skin, and the detergent seems to work effectively. Whenever I travel and shower at a hotel with hard water, I can tell the difference right away.

Regarding the shower door, if you wipe it down clean regularly, you won't have hard mineral stains accumulated on it, of course. In my case, I was lazy and just let it build up over the years, so that's why it became very hard to clean after a while. Now that I realize how hard it is to clean the build up, I've begun to wipe it down regularly and don't have hard-to-clean stain spots on it anymore.

But since I don't want to go up on my roof often to wipe down my solar panels regularly like I can with the shower door, I won't personally want to spray my panels down with regular city water or even soft water and let it dry by itself. I would want to either squeezee it dry, or rinse it with pure water before I let it dry by itself.

[bando]

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.

yes that may well be the case with us since we are likely to overproduce. but a 5% reduction for us would be almost 1000kwh which is significant. our tier 1 starts at 15c and tier 4 is 38c.

hosing off seems to do the trick and gets us 4-5% more output if it hasn't rained in a while (which it hasn't in a few weeks - we haven't had a drop!)

we are planning on getting some pressure washing and windows cleaned soon and will probably ask them to clean the panels even though they are pretty new. it's more to see how the performance varies and give us a good idea of output loss on squeaky clean vs. lightly dust covered vs. caked-on dirt/dust. if we do this i will be sure to keep before/after readings and report back here. of course we have to make sure we keep track of the weather on those days too since a cloudy day reduces output A LOT.

my gut feeling just on what we had from the very beginning to now is 10% loss for "very dirty" and 5% on "light dust cover".

[J.P.M.]

yes that may well be the case with us since we are likely to overproduce. but a 5% reduction for us would be almost 1000kwh which is significant. our tier 1 starts at 15c and tier 4 is 38c.

hosing off seems to do the trick and gets us 4-5% more output if it hasn't rained in a while (which it hasn't in a few weeks - we haven't had a drop!)

we are planning on getting some pressure washing and windows cleaned soon and will probably ask them to clean the panels even though they are pretty new. it's more to see how the performance varies and give us a good idea of output loss on squeaky clean vs. lightly dust covered vs. caked-on dirt/dust. if we do this i will be sure to keep before/after readings and report back here. of course we have to make sure we keep track of the weather on those days too since a cloudy day reduces output A LOT.

my gut feeling just on what we had from the very beginning to now is 10% loss for "very dirty" and 5% on "light dust cover".

Bando: Check your P.M.'s

[silversaver]

Bando,

Have you using the "report" feature on Locus monitoring? Click on "reports", then "Generated vs. Expected". You'll get this screen.

[silversaver]

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 ??

Performance wise, I really don't see any evidence that SP will out performance other makes, maybe small margin. Durability isn't something easy to accommodate.

[J.P.M.]

Performance wise, I really don't see any evidence that SP will out performance other makes, maybe small margin. Durability isn't something easy to accommodate.

Pretty much my point. S.P.'s great stuff, usually overkill and overpriced for what most people need. What I presented is very similar to what I've been observing/recording since getting involved w/my HOA and more than a few cooperative neighbors who have let me see how their systems are doing. I consider that stuff confidential but since this data was already published by Bando and mine is do w/what I please, I thought it may be good info to share. Still anecdotal however.

[silversaver]

Pretty much my point. S.P.'s great stuff, usually overkill and overpriced for what most people need. What I presented is very similar to what I've been observing/recording since getting involved w/my HOA and more than a few cooperative neighbors who have let me see how their systems are doing. I consider that stuff confidential but since this data was already published by Bando and mine is do w/what I please, I thought it may be good info to share. Still anecdotal however.

Yes, that's why I'm here. I'm glad I got the great deal on Bosch discontinued panels and the performance seems par with SunPower (older 225W panel). Again, you got what you pay for but I'm just happen with my solar system after months of research

[J.P.M.]

Yes, that's why I'm here. I'm glad I got the great deal on Bosch discontinued panels and the performance seems par with SunPower (older 225W panel). Again, you got what you pay for but I'm just happen with my solar system after months of research

I've found you get what you pay for or less.