Solar photovoltaic systems basically use silicon mounted on solar panels to covert ordinary sunlight into electricity. The complete solar photovoltaic system consists of the solar PV (photovoltaic) panels, batteries and a charge controller.

There are systems where the battery does not exist and the PV panels generate electricity directly to a load. In other cases this is fed directly to a grid

However the most common setup will include a battery which is charged by the PV panel when there is sunlight and stores the power so that the system remains working at night and even when there is no sunlight directly falling on the PV panels. A charge controller is vital in this situation because it can automatically sense when the batteries are fully charged and cuts off electricity charging it. This ensures that the storage batteries are not over charged which enhances their efficiency and guarantees their long life.

Additionally in a situation where the energy in the batteries has been used up, the charge controller also senses that the battery is low and cuts off further current discharge. This also helps a great deal to conserves the battery because it is never allowed to be drained completely.

Some solar photovoltaic systems will also include an inverter. Usually most household lights and appliances are not designed to use the electricity which comes out directly from the PV system which is direct current (DC) and are instead supposed to use Alternating current (AC) which is the most common type of current produced off the grid. And so this wonderful device called an inverter changes the DC current to AC current which then enables you to use the lights and other AC appliances.

What levels of electricity can a photovoltaic system produce? Actually a PV system can easily produce 4 to 50 kilowatts. The bottom line is that with enough solar panels and plenty of sunlight a photovoltaic system can power a home and even buildings. Admittedly adjustments will have to be made where appliances consume large amounts of electricity to be replaced by energy saving appliances and those specifically designed for use with PV solar systems. Solar systems are very commonly used for electric fences, gates and traffic signs.

One of the big advantages with this kind of solar system is the fact that if designed and installed properly it can give very many years of service with minimal maintenance. We are talking about 20 years or even more.

A commonly asked question is whether PV modules can generate electricity even when it is cloudy. Although the answer to this question is yes, the amount of electricity generated is a tiny fraction of the usual because on a cloudy day the PV panels will tend to receive only at 5 to 10per cent of the usual energy from the sun.

However it should be noted that photovoltaic modules are more efficient at lower temperatures meaning that in cool weather with enough sunlight it will generate a lot more electricity than in similar sunlight but in extremely hot or warm weather.

Because these systems are so much affected by shade where output is reduced a number of precautions and corrective measures to address this need to be taken during installation. You need to remember that there are many different types of shade that could affect the performance of a PV module. Fallen leaves on the panel, snow, and all kinds of dirt can also create shade on the solar panel. One of the ways of easily dealing with this is to pay special attention to the angle of the panels. Tilted at least 12 degrees, most solar panels should be able to provide enough tilt for the panel to self clean as dirt is easily blown away by the wind and rain water washes off any persistent objects providing shade that is not required to the panel. And then the snow on the panel will tend to melt much faster than the snow on the rest of the roof.

Occasionally you will have to clean the panels and the best way to do this is to use plain water. Detergents and cleaning tools should be avoided as these may create scratches which could damage or diminish the efficiency of panels and solar photovoltaic systems.