In 'off-the-grid' systems for remote areas, there is no mains power source. Such systems come almost always with the need for electricity storage, which is managed with battery banks.
In all the off-grid systems there are one or more solar modules mounted outside, facing the sun, and there are batteries to store the solar electricity and release it when it is needed. The number and size of the modules and batteries depends on how much daily energy is needed. The system can be quite large, or quite small, depending on the load. A charge controller is vital to prevent the PV panels overcharging the battery. Charge regulation is needed to prevent excessive water losses, overheating and reduction of battery life.
During the day, the PV array produces enough During the night, the load continues to be powered,
energy to power the load and to charge the battery. drawing on energy stored in the battery.
1 Solar Modules 2 Controller 3 Fusebox 4 Battery Bank 5 Loads