Just as an automobile uses a voltage regulator to control the charging voltage to the battery, a similar type of controller is used in PV systems to prevent overcharging the battery bank. PV charge controllers limit the current from the PV array to the batteries once the batteries reach a pre-set voltage limit. The load disconnect feature, disconnects the electrical load from the batteries when they reach a un desirable or too low state of charge. The conversion from DC to AC power is achieved with a separate component called an inverter. An inverter makes it possible to use all of the normal appliances in a home such as TVs, coffee pots, microwave ovens, dishwashers, clothes washers, power tools and water pumps.
Inverters can also power office equipment such as computers, copiers and facsimile machines.
An optional component for PV systems is a back-up engine generator. A back-up generator often results in a system with lower initial cost, lower cost of energy, more flexibility and more reliability. This is because for a small incremental cost, a generator can provide additional energy for times the sun doesn't shine or more energy is needed. Another optional component is a solar tracker. A solar tracker increases energy production by tilting PV modules toward the sun throughout the day.