If you are talking submersible, I have had good luck with a solar well pump. I use a Grundfos SQFlex. No batteries, charge controllers, or inverters. Hooked directly to the panels. As the name implies, the pump is pretty flexible. It will run off AC too. Just need a tank to store above ground for nighttime use. I put it in when my AC pump went out. Close to the same price as a AC unit.