Oct 14, 2026Product Planning
Solar Skimmers on Cloudy Days: What to Expect
A solar skimmer runs on its battery and the panel tops it up. What a grey week does to runtime, where the adapter fits in, and what to tell owners.
The message tends to arrive after a run of grey days: the skimmer has stopped in the middle of the pool. Often nothing is wrong with it. The battery ran down because the panel had too little light to put back what the skimmer used, and nobody had told the owner what to do next.
We build two solar skimmers, the S100 and the Y90 Pro, and we've already written about what to check before you put your logo on one. This piece covers a narrower question buyers keep sending us: what happens to a solar skimmer when the sun doesn't cooperate, and how should a retailer set expectations so a cloudy week doesn't turn into a return?
Does a solar skimmer stop when it's cloudy?
It keeps going as long as the battery has charge. Think of the battery as the tank and the panel as the top-up. On a bright day the panel puts energy back while the skimmer works. Under heavy cloud it puts back very little, so the skimmer is mostly living on what the battery stored earlier. One grey day after a sunny spell usually goes unnoticed. A whole grey week, with the panel never catching up, will show: the skimmer can run a little shorter each day until it stops.
What does the 20 W on the box actually mean?
A panel's watt rating describes its output in strong, direct sun. Our S100 carries a 20 W panel and the Y90 Pro a 10 W one, so the S100's panel has twice the rated output in the same light. The S100 is also rated for up to 25 hours on a charge. Treat both figures as best cases. Morning shade from a fence, a film of pollen on the panel or a low autumn sun all cut what the panel delivers, long before anyone would call the day cloudy. That's one reason we'd suggest the S100, rated for pools of 150–200 m², for larger pools and gardens with trees. It's also why owners should wipe the panel whenever they empty the basket.
When should owners use the adapter?
Both of our skimmers charge from the sun and from an adapter. We'd present the adapter as part of the routine from day one, so it never looks like a fallback for a faulty product. Three moments matter most: before the skimmer's first day in the pool, after it has sat in storage, and after a run of grey days when it's clearly running short. A full adapter charge at those points means the panel only has to keep up, and keeping up is what a small panel does well.
How should we describe runtime in our listing?
Many cloudy-day complaints start with the listing. If the title says solar-powered and nothing else, the shopper pictures a skimmer that never needs a plug. Put "solar and adapter charging" in the title or the first bullet, write the runtime as "up to", and add one plain line about weather: on cloudy days the skimmer runs on its battery, so top it up with the adapter. On the quick-start card in the box, show the adapter next to the panel. It's a small change to the artwork, and it costs far less to make before the boxes are printed than after the first wave of questions.
What should our support team ask first?
When an owner says the skimmer stopped, start with light and charge before anything about faults. How much direct sun has the pool had this week? Is the panel clean and out of shade? When was it last charged from the adapter? On the S100, the app shows the battery level, so an owner can see it running low before it stops. If a full adapter charge brings back a normal day's skimming, it was an energy problem. If it doesn't, that's when the unit needs a closer look, and spare parts, chargers and batteries can be ordered separately so your team can fix it without replacing the whole skimmer.
FAQ
Does a bigger panel help in cloudy weather?
It helps the battery recover faster in the same light. The S100's 20 W panel has twice the rated output of the 10 W panel on the Y90 Pro. Neither panel makes up for a full week without sun, which is what the adapter is for.
Which model would you sell in a cloudy market?
We'd lean toward the S100 for its larger panel and longer rated runtime, and we'd make adapter charging clear in the listing whichever model you choose. The Y90 Pro, rated for pools of 100–150 m², suits smaller pools in sunnier spots.
Selling solar skimmers into a market with long grey spells? Tell us your market and typical pool sizes in the form below. We'll suggest a model and go through charging and runtime with you. Our team will reply by email within 1 business day.
Written by the Silver Home R&D and quality team.
