Solar power increase after cleaning panels

[1am7h30n3]

Ok I'm going to start off by saying that I've never been a believer in cleaning solar panels, all the times I've seen people mention it they've done something like measure 1kW of solar production and then climb on their roof and clean the panels with cold water and then immediately run back to their inverter and see 1.5kW and go wow I've just improved my production by 50% (or whatever number), and then get all disappointed when the "improvement" disappears in a few hours as the cooling effect of the water wears off, etc.

I've never cleaned my solar panels (installed about 1 year ago). I live on a dirt road, so there's plenty of dust flying around. It's been a dry winter. So my panels were really filthy, think brown, not black.

I picked one day which (by looking at the shape of the solar production graph in my logs) was a nice clear day and was before we had the first proper rain of this season in my area, this day was 14 October 2022. Last night we had a very nice rain which would have cleaned the panels off a bit and today was perfectly sunny, so I chose today, 25 October 2022, as my "clean panel comparison" day. I noted down the solar production kW for a few times in the morning for each day and made a table to compare them.

time	dirty (kW)	clean (kW)	% inc
06:00​	0,05​	0,07​	40​
06:30​	0,12​	0,19​	58,33333​
07:00​	0,26​	0,44​	69,23077​
07:30​	0,45​	0,68​	51,11111​
08:00​	0,63​	0,91​	44,44444​
08:30​	0,79​	1,12​	41,77215​
09:00​	0,95​	1,29​	35,78947​
09:30​	1,1​	1,43​	30​
10:00​	1,21​	1,57​	29,75207​
10:30​	1,31​	1,69​	29,00763​

Honestly I'm very impressed, that's a huge increase in production and that's not even proper cleaning, it's just a rain water rinse off. I'm converted, I was wrong, apparently cleaning solar panels does make a big difference.

 

[3WA]

You just convinced me not to get solar. More housework.

 

[Priapus]

Ok I'm going to start off by saying that I've never been a believer in cleaning solar panels, all the times I've seen people mention it they've done something like measure 1kW of solar production and then climb on their roof and clean the panels with cold water and then immediately run back to their inverter and see 1.5kW and go wow I've just improved my production by 50% (or whatever number), and then get all disappointed when the "improvement" disappears in a few hours as the cooling effect of the water wears off, etc.

I've never cleaned my solar panels (installed about 1 year ago). I live on a dirt road, so there's plenty of dust flying around. It's been a dry winter. So my panels were really filthy, think brown, not black.

I picked one day which (by looking at the shape of the solar production graph in my logs) was a nice clear day and was before we had the first proper rain of this season in my area, this day was 14 October 2022. Last night we had a very nice rain which would have cleaned the panels off a bit and today was perfectly sunny, so I chose today, 25 October 2022, as my "clean panel comparison" day. I noted down the solar production kW for a few times in the morning for each day and made a table to compare them.

time	dirty (kW)	clean (kW)	% inc
06:00​	0,05​	0,07​	40​
06:30​	0,12​	0,19​	58,33333​
07:00​	0,26​	0,44​	69,23077​
07:30​	0,45​	0,68​	51,11111​
08:00​	0,63​	0,91​	44,44444​
08:30​	0,79​	1,12​	41,77215​
09:00​	0,95​	1,29​	35,78947​
09:30​	1,1​	1,43​	30​
10:00​	1,21​	1,57​	29,75207​
10:30​	1,31​	1,69​	29,00763​

Honestly I'm very impressed, that's a huge increase in production and that's not even proper cleaning, it's just a rain water rinse off. I'm converted, I was wrong, apparently cleaning solar panels does make a big difference.

@Neuk_ and I have been down this route. Don't care what the data says, I am not cleaning my panels again. At most, I'll just hose them down, if I feel like it.

But a whole 0.38kWh is not enough motivation for me.

 

[1am7h30n3]

You just convinced me not to get solar. More housework.

Or just be lazy like me and wait for the rain to do the work for you

 

[1am7h30n3]

@Neuk_ and I have been down this route. Don't care what the data says, I am not cleaning my panels again. At most, I'll just hose them down, if I feel like it.

But a whole 0.38kWh is not enough motivation for me.

I don't know if I can ever see myself wasting water and time cleaning solar panels, especially in South Africa where we have water restrictions (but the dams are full, anyway...). 0.38kW isn't much, I agree, but my system is tiny, so it's a 30% increase for me, that does make quite a big difference. I'm more in this for the interest, I wanted to know how much difference it would make, I'm certainly not recommending anyone to go out and clean their panels (it would likely depend on how dirty the panels are, I live on a dirt road, most don't, etc.).

 

[Neuk_]

@Neuk_ and I have been down this route. Don't care what the data says, I am not cleaning my panels again. At most, I'll just hose them down, if I feel like it.

But a whole 0.38kWh is not enough motivation for me.

Every time I think of cleaning my panels I think of you laughing at me and I just hose them down.

 

[RonSwanson]

Panel efficiency benefits more from the cooling effect of the water than from being clean. That said, the cooling effect is short-lived (they heat up again within a few minutes) and they do benefit from a quick clean (a few squirts from a domestic hose-pipe), especially if it is a large array. I personally do not do the "COVID-19 deep-cleansing" that others do (soap, brushes, squeegees and mops) but instead just give them a few squirts from afar, about twice during the dry winter season. Even stubborn Hadeda poop just needs a bit of a soak and another squirt.

 

[Mike Hoxbig]

Panel efficiency benefits more from the cooling effect of the water than from being clean. That said, the cooling effect is short-lived (they heat up again within a few minutes) and they do benefit from a quick clean (a few squirts from a domestic hose-pipe), especially if it is a large array. I personally do not do the "COVID-19 deep-cleansing" that others do (soap, brushes, squeegees and mops) but instead just give them a few squirts from afar, about twice during the dry winter season. Even stubborn Hadeda poop just needs a bit of a soak and another squirt.

Even once the cooling effect wears off, the benefit is still that there's less dust blocking the light from getting in...

 

[HowTo]

I think we should nail the culprit, Esdom.
Otherwise we should be fine.

 

[Snyper564]

Ok I'm going to start off by saying that I've never been a believer in cleaning solar panels, all the times I've seen people mention it they've done something like measure 1kW of solar production and then climb on their roof and clean the panels with cold water and then immediately run back to their inverter and see 1.5kW and go wow I've just improved my production by 50% (or whatever number), and then get all disappointed when the "improvement" disappears in a few hours as the cooling effect of the water wears off, etc.

I've never cleaned my solar panels (installed about 1 year ago). I live on a dirt road, so there's plenty of dust flying around. It's been a dry winter. So my panels were really filthy, think brown, not black.

I picked one day which (by looking at the shape of the solar production graph in my logs) was a nice clear day and was before we had the first proper rain of this season in my area, this day was 14 October 2022. Last night we had a very nice rain which would have cleaned the panels off a bit and today was perfectly sunny, so I chose today, 25 October 2022, as my "clean panel comparison" day. I noted down the solar production kW for a few times in the morning for each day and made a table to compare them.

time	dirty (kW)	clean (kW)	% inc
06:00​	0,05​	0,07​	40​
06:30​	0,12​	0,19​	58,33333​
07:00​	0,26​	0,44​	69,23077​
07:30​	0,45​	0,68​	51,11111​
08:00​	0,63​	0,91​	44,44444​
08:30​	0,79​	1,12​	41,77215​
09:00​	0,95​	1,29​	35,78947​
09:30​	1,1​	1,43​	30​
10:00​	1,21​	1,57​	29,75207​
10:30​	1,31​	1,69​	29,00763​

Honestly I'm very impressed, that's a huge increase in production and that's not even proper cleaning, it's just a rain water rinse off. I'm converted, I was wrong, apparently cleaning solar panels does make a big difference.

Had some nice rain today - I will also do the comparison tomorrow and last week.

 

[AmazeBalls]

Definitly saw an improvement. Was maxing out at 6kw, now getting around 7kw which is in line around the same time last year when i had it installed.

 

[Sepeng]

Ja look, I don't monitor my system nearly as close as I should so can't say for certain, but I'm pretty sure my max has increased quite a bit these last few days. So sure, my anecdotal opinion is to agree with you.

 

[TheChamp]

Another factor to consider is that it is generally cooler after it rained, so you have clean panels, nice sunlight without the heat, it's a recipe for a good yield.