I just installed a 20 watt solar panel on the arbor to power a direct current pump that I want to use to circulate water in the pond. I don't want to have to run A/C power out to the pond and since I am not raising koi, aeration isn't as critical.
I want to have the sound aspect and to also prevent the stagnation that would make mosquitoes an issue.
As the amount of current varies with the intensity of the sun, the pump's flow also will vary. When the sun is bright the pump is providing plenty of flow to suit the needs of this small water feature. Obviously it won't run a night but it should oxygenate the water enough during the day to support some very small fish.
I am still in the process of arranging the pondscape so nothing is final yet. I mainly just wanted to have the pump running now because it is warming up and mosquitoes will be looking for a place to lay eggs very soon. I'm going to add a few goldfish soon as well.
Today was a sunny day, mostly, and the pump was still working just slightly after 5 p.m. so I think the panel is in a good location, so far. I set it to local latitude so it's on about 33 degrees, due south.