I want to install a solar water-pump or a windmill water pump to extract water from an aquifer without stop during the day (constant flow). The solar water-pump is less expensive and comes with the extra feature of using solar panels I have. My question is, is it somehow bad for the battery and/or the solar pump to be running 8/10 hours a day every day? should I better consider the windmill water pump?
Compared to a battery an elevated water tank is the better energy storage for times without sun or wind if the energy is solely needed for water pumping. Double conversion of energy (to electricity and back to use) and loss of energy in the battery, which even will age, will waste a lot of energy and money.
Hight of water tank depends on the pressure you need to distribute the water later. In many cases it must not be very high. Which kind of "energy converter" you should use depends on the availability of wind or sun and technology.
On the country side a wind turbine may operate the water pump directly without electrical energy conversion. So it is even much easier to repair. If there is sufficient wind available that would be my preferred solution, even when it appears to be quite old fashioned.