Turning Light into Solar Electricity

The process of converting light (photons) to electricity (voltage) is called the solar photovoltaic (PV) effect. Photovoltaic solar cells convert sunlight directly into solar electricity.

These solar power cells are commonly used to power everything from calculators, watches and battery chargers to road signs and security alarms.

PV solar energy cells are made of semi-conducting materials similar to those used in computer chips. When sunlight is absorbed by these materials, solar energy releases energy from their atoms allowing the electrons to flow through the material to produce solar electricity.

Photovoltaic(PV) systems

There are 4 main components in most solar photovoltaic (PV) systems.

1. The first is the solar array which is a collection the power producing cells. This converts the suns energy into DC electricity.
2. The second is the roof mounting structure consisting of aluminium or stainless steel components that are used to mount the solar collector system onto the roof of the building. There are two major types; (1) roof integrated where the solar electricity panels replace the tile and become flush with the rest of the roof (2) on-top mounting where the solar electricity panels sit above existing roof tiles.
3. A special solar energy inverter is then required to convert the DC (direct current) electricity into AC (alternating current) electricity, which can be used by most home appliances or sold back to the grid.
4. The final part is when the solar collector system is linked to your fuse box and an electric meter so you can tell how much energy you have produced and how much unused energy you have sold back to the grid.

Cells, Modules and Arrays

The basic PV building block is the photovoltaic cell. Referred to as a "cell", because it produces direct current (DC) electricity like a battery, a PV cell converts energy from the sun directly into solar electricity. In practical applications of photovoltaic energy, groups of cells are unified to form a module (modules may be connected into an array).

Storage of Energy

Photovoltaic PV systems can be designed to sell any surplus energy back to electricity grid rather than store the energy. This overcomes many of the shortcomings of using batteries; including high cost, storage, limited useful lifespan and environmentally unfriendly components.

In some remote areas, however, there may be no connection to the grid available making the use of batteries a necessity.