This is listed as an 8.5W solar panel online, but the specs say 10.6W. Little solar panels like this can be alright in direct sunlight but I’d advise, for most cases, to buy something a bit bigger otherwise you’ll just get 1A (standard speed charge) max. That’s not taking into account light fluctuations and whatnot that happen with the sun. This one also made an audible whine at lower current outputs. But otherwise it seems to work fine in direct sun. This power bank does not store power, so a separate USB battery bank would be required if you want to keep energy overnight.