Solar water pumps may not seem to make that much sense in an urban area that gets all electricity that it needs. Going solar with water pumps though, could make a lot of sense when you consider a rural set up. There are all kinds of remote places everywhere that need the use of a water pump, and that just don't have a convenient connection to the grid.
Take a rural farm or ranch for instance. You find all kinds of applications in this kind of set up where solar water pumps would go perfectly. You could need water in all kinds of remote locations in such a place.
Of course, there are other ways in which you could pump water for free with a windmill for instance. But solutions like those happen to be expensive and fussy. Solar water pumps on the other hand just need a modest amount of sunlight, and you're good to go.
The thing with solar water pumps is that you don't even need to worry about power storage. These are not lights that you might need to turn on on demand. Water pumps are usually used to pump water up to a storage tank. It doesn't matter when you do your pumping. When the sun shines, the pump keeps pumping. Your pump fills your tank up whenever it can. You could say that your tank acts like a storage battery for you.
Solar water pumps usually work on very low voltage direct current. They aren't the kind that you might plug into a wall outlet. Of course, this tends to mean that solar pumps don't pump water very quickly. They're typically quite low speed about 1 gallon a minute.
While the number might seem a little disappointing, you have to understand that you don't really spend anything on this. It runs slow and steady and manages in most situations, to pump about 400 gallons of water a day. That's more or less all you need most of the time.
There are a number of components that go into a solar water pump installation. To begin with, you do need the solar array that actually supplies the power you need. You could install one of these practically anywhere. In the northern hemisphere, having your array face south somewhat, would make a lot of sense. It would help it catch the most sunshine.
A pole-mounted solar array would make a lot of sense. Each time the seasons change and the sun appears in a slightly changed aspect, you just need to twist the pole around to help the array face the sun.
For the most part, an average home-sized solar module should be able to put out maybe 17 volts. Usually, a solar array should be able to put out at least this much no matter how cloudly it is. That's the minimum.