Stand-alone PV system uses batteries to store the energy generated by the solar modules during daytime. The energy yield of the stand-alone system is matched to the energy demand of the connected loads. Since the most energy is not needed during daytime, it is stored in rechargeable batteries and it is used when the sun is not shining and the modules are not producing enough electricity to power all electrical appliances, like night or cloudy and raining days. It is important that the solar PV system is properly sized to produce the needed electricity to store it in the batteries to power the loads at nights and cloudy days.
How stand-alone PV system works?
The DC electricity produced by the solar modules in a typical stand-alone pv system is used to charge batteries via a solar charge controller, which is connected to the solar modules. The charge controller is then connected to a battery bank and charges it by the power from the solar modules. The battery bank is then connected to an inverter, which converts the DC power from the battery into AC electricity. All AC loads connected to the Stand-alone system are then connected to the inverter, while all DC appliances are connected direct to the charge controller.