Should you wash your solar panels? • Hacker News Board

Re: Should you wash your solar panels?

#51

Post by longitudinal93 » Mon, Jul 27, 2026, 2:46 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.

This simple procedure increases the selling price of everything. Just a fact.

Re: Should you wash your solar panels?

#52

Post by delichon » Mon, Jul 27, 2026, 2:47 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.

We had a contractor doing repairs before we sold our house. Without being asked he took an orbital sander to the wooden hand railings along the stairs to the front door and said "people really notice this".

A family came for the tour and before walking in the father put his hand on the rail, looked up at the house, and said "this place seems well maintained". Then they bought the house after a small pleasant (for us) bidding war.

The contractor earned his high rate and then some.

Re: Should you wash your solar panels?

#53

Post by austinl » Mon, Jul 27, 2026, 2:47 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.

Having recently bought a house, I love thinking about things that increase perceived value relative to cost (more so because they're nice to have, not because we plan to sell any time soon).

A few things we changed right away: - new mailbox (replacing a rusted 30+ year old one) - lots of landscaping work (the majority of which I can do myself) - installed a wine fridge (I always felt it gave the sense that the kitchen was upgraded when we were touring places) - replaced old door knobs with modern matte black levers; ~$50 each

The house was built in 1968, so it's been interesting to think about all of the small things that make it feel dated that can be changed for not much money.

Re: Should you wash your solar panels?

#54

Post by tombert » Mon, Jul 27, 2026, 2:48 PM UTC

I haven't noticed too much of a power increase in my backyard solar farm after cleaning, but I do notice a very significant increase by weeding the surrounding stuff. Even a pretty small amount of shade will very significantly reduce your yield, like seriously 20-30%.

Oh, also, I've noticed that at least with my panels, bird poop seems to be particularly bad. The dust that accrues doesn't seem to do much, but even a relatively small bit of bird poop will be almost as bad as weeds. Fortunately it's not terribly difficult to clean once it's dried.

Re: Should you wash your solar panels?

#55

Post by peter_stokes » Mon, Jul 27, 2026, 2:49 PM UTC

bebe8393jrir wrote: post #5

> If I increase the power output of the system then the additional capacity will not be eligible for the feed-in tariff and will revert to present-day prevailing tariff which is about 4x worse before you even consider that I currently get to use electricity and still get paid for generating it. > This is the yin and yang of market-distorting incentives. Today's incentive to install solar becomes tomorrow's disincenti…

when it first started it was basically 450GBP/MWh (In 2010 GBP). and that was paid for every kWh generated (whether exported or not). And the PPA lasts for 20-25 years.

Re: Should you wash your solar panels?

#56

Post by dd8601fn » Mon, Jul 27, 2026, 2:50 PM UTC

DharmaPolice wrote: post #44

wongarsu wrote: post #31

Earlier quoted context omitted.

Exactly. "Is it clean and tidy right now" is a decent proxy for "Has this been properly taken care of in the past" Obviously it's not infallible. But even if the owner only cleaned their stuff now that they are selling it that still tells you they are the type of person to take action where it's beneficial

I think it's more of a negative indicator. It's like turning up to a job interview wearing dirty clothes - unless you're a savant it's probably indicative that you don't give a shit or have some sort of other problems in life. But wearing clean clothes doesn't give you points because it's assumed to be the norm in that setting.

Right. Clean house on the market means almost nothing.

Gross house means almost certainly not maintained.

Re: Should you wash your solar panels?

#57

Post by bruce511 » Mon, Jul 27, 2026, 2:50 PM UTC

rcxdude wrote: post #34

cestith wrote: post #21

Earlier quoted context omitted.

Tracking systems are also becoming more popular. You spend a little more up front but get a lot more usable power.

I get the impression they are getting less viable because the extra cost and maintenance outweighs just putting more panels down. There are some calculations that suggest even mounting them on angled frames might not be worth the cost, depending on how dirty they get when you just lie them flat on the ground. (This assumes that you have enough space, but for grid-scale solar this is not the limiting factor. The costs…

I can speak to this somewhat. My panels are on adjustable frames. Typically I switch from flat (summer) to tilted (winter).

As always ymmv and depends somewhat on your location. I'm around 30 degrees from the equator.

During summer, lying flat gets a lot more power. And more importantly the start and end of the generating period is longer. Ie the panels get more sun in the morning and evening thankfully they were tilted.

In winter the sun is more "from one direction" and obviously is lower on the horizon.

Re: Should you wash your solar panels?

#58

Post by ChrisMarshallNY » Mon, Jul 27, 2026, 2:53 PM UTC

I know that dust on the panels is one of the reasons that one of the Mars rovers eventually croaked.

Re: Should you wash your solar panels?

#59

Post by left-struck » Mon, Jul 27, 2026, 2:53 PM UTC

namdnay wrote: post #26

ape4 wrote: post #24

I imagine rain will clean them. In most places it rains every so often.

my experience is that unless you get some really torrential rain, it's not enough to clean the sand/dust/grime

Can confirm, my car doesn’t get cleaner unless there’s a downpour

Re: Should you wash your solar panels?

#60

Post by skippyfish » Mon, Jul 27, 2026, 2:54 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.

It's not just emotions, it's also a matter of time and uncertainty.

I was in a buying situation where my old lease was expiring soon, I had a second kid on the way, and the last thing I'd have wanted is to buy a place where I'd have contractors milling around for weeks or months to make various repairs. I was willing to pay a hefty premium for a place that's in a move-in condition.

I don't think this extends to "you'll get $10k less if you don't vacuum", but it's a common courtesy on a million-dollar transaction to maybe not leave a mess.