Just measured my little solar charger output on a cloudy day here in Portland

I always thought clouds meant basically zero power, but my 10W panel still put out 3.2 watts at noon with thick overcast. Got this from a Kill-A-Watt meter hooked up to a battery, has anyone else tested theirs in bad weather?

2 comments

2 Comments

margaret_bennett31mo ago

Your mileage may vary but most panels still pull something even in heavy overcast conditions.

sarahsullivan1mo ago

Is that true even for the older polycrystalline panels, or more the newer monocrystalline ones? I read something recently from a guy who tested a bunch of panels in dreary Pacific Northwest weather, and he said the older panels basically gave him nothing, but the newer ones still put out maybe 10-15 percent. So he was all about upgrading just for that reason. I guess it depends on the panel's specific specs and the exact shade of grey the sky is. But still, good to know that even a little wattage can help top off a battery bank.