Solar pumps are used for private homes, villages medical clinics, etc. A water pump can be powered by its own PV array or by a minimal system that powers lights and appliances. In a combined system, more configurations are possible. An elevated storage tank may be used or a second pump called a booster pump can provide water pressure. Or, the main battery system can provide storage instead of a tank.
Rain catchment can supplement solar pumping when sunshine is scarce.
To design a system, it helps to view the whole picture and consider all the resources. There are no limits to how large a solar pump can be built. But, they tend to be most competitive in small installations where combustion engines are least economical. You may be surprised by the performance of such a small system. Slow solar pumping lets us utilize low-yield water sources.