Impressive in full sun, anemic in overcast,
Verified Purchase(What's this?)
I bought this for a solar-powered waterfall fountain. This project requires a vertical lift of approximately 5-6 feet, which I thought might be a little optimistic for this system - especially in the wetter part of the pacific northwest. On a day with moderate scattered cloud cover, it was quite interesting to see the pump at work in varying levels of light. When in full sun, the pump/panel system was extremely impressive, putting out a surprising amount of flow for the height. When a cloud would pass by, even a seemingly trivial decrease in apparent brightness would result in the flow being reduced to a trickle, or not at all. Today is overcast, and the pump (hooked only to a small fountain head, only about 12 inches of lift) barely dribbled some water when there was almost a sunbreak. My overall impression is that this system is well-suited to applications where *bright, unobstructed* sunlight is expected during the intended periods of use. In these conditions, the pump seems to be roughly capable of the stated output. I cannot comment on the durability of the pump or the panel at this point.
I have purchased another larger-capacity solar panel to see if I can improve the performance in less optimal conditions, and will report on this later.
Update 5/6 - I ordered the Instapark 100 wattInstapark® NEW All Black 100W Mono-crystalline Solar Panel, 100 Watt solar panel - and this does considerably improve performance in less than optimal conditions. In this context, I will probably end up using both panels, the larger panel for the main part of the day, and the smaller panel positioned to get direct sun later in the day. I think that the 40 watt panel is a little underpowered for the pump in non-optimum conditions, but does fine when conditions are perfect.