The major limiting factor in water powered pumps is, of course, that you need flowing water and some degree of head pressure to drive the pump.

The major benefit with water-powered pumps is that they will pump all day and all night regardless of weather, this can give you some significant quantities of water over a 24-hour period and makes no difference what season it is.

The major limiting factor in solar-powered pumps is that, obviously, the sun needs to be shining, meaning you can expect days when the pump will deliver little, or even no water. In winter you can expect significantly less water than in the summer.

The way to mitigate the inconsistencies of the sun is to pump more water per day than you need to a storage tank or reservoir. This allows you to have a bank of water in the system that can accommodate the down days, effectively turning your tank/reservoir into a battery.

The major benefit with solar is your water source can be either flowing or still water, which opens solar up to all water sources. Good quality solar pumps, installed correctly, are very reliable.

Off-grid pumping can deliver significant benefits. Do your homework, follow the guidelines and you can expect a great result.