How do the stand alone PV systems work?
A basic stand alone PV system consists of the solar panels, batteries and a charge controller. The photovoltaic solar panels generate DC (direct current) electricity, which is used to charge the storage batteries. A charge controller is needed to keep the batteries from being over charged. The batteries store the energy, and are similar to those used to start cars, but the batteries used in solar systems are designed to store and discharge energy over a longer period and at slower rates than the short, big surge needed to start a car. These storage batteries gradually store the power generated during the day for use at night or during cloudy days. This stored energy can then operate DC appliances such as radios and the lights found in recreational vehicles. An inverter can be added to change the DC into AC so standard appliances such as hair dryers and microwave ovens can be used.
