In order to help you figure out what you need in order to be able to pump water with a solar-powered pump we will need the following information:

1) Number of gallons per day required. For example, cows avg. 20-30 gallons each per day, avg. household consumption is 300-500 gallons per day for a family of four. Of course, there are a lot of variations there so each situation will be different.

2) Location. This is important because the amount of solar energy is dependent on the area and weather conditions.

3) Type of well-2" wells are probably the least suited for solar power, anything 3" and above will probably be compatible with solar pumps.

4) Whether or not utility power is available and how you plan on using the power. Solar power will probably never be comparable with grid power in terms of start-up costs or running cost unless there are some special circumstances. For example, if it costs you $10,000 to run utility power for a well then you can probably install a solar pump for less cost. If you're doing this as part of a dooms-day scenario then that will also play a factor.

Of course this section will change as our knowledge evolves so stay tuned.