Should you wash your solar panels? • Hacker News Board

Re: Should you wash your solar panels?

#101

Post by bityard » Mon, Jul 27, 2026, 4:55 PM UTC

jader201 wrote: post #96

CrzyLngPwd wrote: post #90

I clean my solar panels, 7kwh, every monmth or two. When I check on the VRM portal it makes a difference, and since I am so dependent on them all year round, I have no problem giving them some attention from time to time. Ten mins well spent.

> I clean my solar panels, 7kwh, every monmth or two. This honestly sounds like a non-trivial strike against installing solar panels, especially if they’re installed on tall roofs. I definitely wouldn’t want to have to clean them that often, or pay to have them cleaned that often. If you’re spending only 10 minutes on them, then maybe you don’t have that many, and they’re not up high.

Roof-mounted solar panels are a necessity in urban situations but they are a maintenance nightmare compared to a ground-mounted array. That has to be accepted as "the cost of doing solar" when there is no other alternative.

Re: Should you wash your solar panels?

#102

Post by metadat » Mon, Jul 27, 2026, 4:56 PM UTC

jader201 wrote: post #96

CrzyLngPwd wrote: post #90

I clean my solar panels, 7kwh, every monmth or two. When I check on the VRM portal it makes a difference, and since I am so dependent on them all year round, I have no problem giving them some attention from time to time. Ten mins well spent.

> I clean my solar panels, 7kwh, every monmth or two. This honestly sounds like a non-trivial strike against installing solar panels, especially if they’re installed on tall roofs. I definitely wouldn’t want to have to clean them that often, or pay to have them cleaned that often. If you’re spending only 10 minutes on them, then maybe you don’t have that many, and they’re not up high.

On tall roofs there tends to not be much dust.

Re: Should you wash your solar panels?

#103

Post by john01dav » Mon, Jul 27, 2026, 4:59 PM UTC

delusional wrote: post #36

wodenokoto wrote: post #6

> why would you clean them when you're about to sell the house? So they look good and the potential buyer sees something that looks to be in good condition and working well.

Exactly the same reason you should probably clean the rest of the house when you're selling it. Theoretically, the price of the house before cleaning should be equal to the value if the house after cleaning, minus whatever the cleaning costs. In reality, you'll get much less for your house without cleaning it, because human emotions.

Being rational about this (i.e., buying a dirty or otherwise manageably flawed house) is a great way to save or make money in markets where the majority of the cost is the building.

Re: Should you wash your solar panels?

#104

Post by bityard » Mon, Jul 27, 2026, 5:02 PM UTC

ynac wrote: post #83

There are at least a couple of outfits claiming a nano coating or a nano glass surface for solar panels that are so smooth as to not collect dusts. Their other claim is greatly improved angular photon capture since the panel is just that flat. The two companies I've seen claim ~20% improvement - and less maintenance.

20% seems high enough that if it was really _that_ effective, the companies making the panels would be tripping over themselves to buy this coating to apply it to the panels right in their factories. (And charge a premium for it.)

Re: Should you wash your solar panels?

#105

Post by john01dav » Mon, Jul 27, 2026, 5:02 PM UTC

harrall wrote: post #50

delusional wrote: post #36

Earlier quoted context omitted.

Exactly the same reason you should probably clean the rest of the house when you're selling it. Theoretically, the price of the house before cleaning should be equal to the value if the house after cleaning, minus whatever the cleaning costs. In reality, you'll get much less for your house without cleaning it, because human emotions.

It’s not just emotions, it’s a sign that, when presented with something annoying that you should do but not strictly required, it shows that you pushed through and did it anyway. It doesn’t prove that you’ve been generally on top of things for the lifetime of the house but the inverse situation where you couldn’t clean one time for guests sure doesn’t.

There are other reasonable interpretations of such things. More precisely, one may simply care in different ratios about various things than is typical. For example, one may be fastidious with replacing furnace filters and water heater anode rods while not caring about their lawn beyond city or hoa mandates.

Re: Should you wash your solar panels?

#106

Post by bityard » Mon, Jul 27, 2026, 5:03 PM UTC

dd8601fn wrote: post #64

varispeed wrote: post #27

Earlier quoted context omitted.

In many countries it is actually illegal to use tall ladder etc. owners would have to erect a scaffolding to make access for work people to clean it safely.

There are definitely some wacky nanny state rules out there… but I’m a little skeptical of “In many countries it is actually illegal to use tall ladder”

It would not surprise me if this was a law in Germany, for example.

Re: Should you wash your solar panels?

#107

Post by scarecrowbob » Mon, Jul 27, 2026, 5:04 PM UTC

CrzyLngPwd wrote: post #90

I clean my solar panels, 7kwh, every monmth or two. When I check on the VRM portal it makes a difference, and since I am so dependent on them all year round, I have no problem giving them some attention from time to time. Ten mins well spent.

I am curious how much of a difference it makes.

I have 4kw of panels and 15kwh of storage. I only get down to about 80% most nights (I heat with wood and propane).

But my system will charge completely in about 2 hours of full sun. If it took 3 hours it wouldn't make a difference. So I generally don't clean them (well, the rain and snow do that work).

I do remove snow, because that has a very noticeable impact.

Is the difference that you are pushing back to a grid (I am not), so the power all gets used regardless of you being the one to use it?

Re: Should you wash your solar panels?

#108

Post by jaggederest » Mon, Jul 27, 2026, 5:06 PM UTC

the_sleaze_ wrote: post #77

Question for people here: my local power company charges a fee if solar is attached to the grid and is high enough to make installing residential solar impractical. I'm thinking the best thing to do would be put a large battery in between the grid and my home and selectively recharge the battery with the solar. I believe that setup circumvents the fee since the only thing using energy is the battery, as though it wer…

> I believe that setup circumvents the fee since the only thing using energy is the battery, as though it were an off grid setup.

Entirely based on your jurisdiction, but that kind of zero-export requires the same permits and connection fee as a full net metering in mine. You can't end run the process by just being sneaky, electrical work needs permits and they'll either make you take it out (!!) or bring it into full compliance.

As an example, my utility is one of those ones that requires a separate manual disconnect, even though the vast majority of all-in-one inverters have a built in disconnect. It doesn't make any sense and it's at least two grand in permit + equipment, but that's the rule.

Re: Should you wash your solar panels?

#109

Post by alberth » Mon, Jul 27, 2026, 5:06 PM UTC

wodenokoto wrote: post #6

> why would you clean them when you're about to sell the house? So they look good and the potential buyer sees something that looks to be in good condition and working well.

OT: a friend of mine recently bought a house. They were surprised to learn at closing that the seller had financed their solar panels and that wasn’t apart of the home purchase.

So they had to negotiate who was going to pay off the solar panel, and this all had to be completed before home sale.

Re: Should you wash your solar panels?

#110

Post by rconti » Mon, Jul 27, 2026, 5:07 PM UTC

ynac wrote: post #83

There are at least a couple of outfits claiming a nano coating or a nano glass surface for solar panels that are so smooth as to not collect dusts. Their other claim is greatly improved angular photon capture since the panel is just that flat. The two companies I've seen claim ~20% improvement - and less maintenance.

My solar panels are leaning in stacks in my yard, as our house is currently being removed with a new roof, etc. I'm planning on cleaning them while they're "loose", but I wonder if it also makes sense to apply a(n automotve-style) ceramic coating to them.