Solar photovoltaic – how it works

Solar Photovoltaic (PV) panels on the roofs of homes and businesses capture the sun’s energy to generate electricity cleanly and quietly. Light energy is converted directly into electricity by transferring sunlight photon energy into electrical energy. This conversion takes place within cells of specially fabricated semiconductor crystals.

While it might be true that solar cannot generate electricity all the time, it does generate electricity when it is needed most – during the day and on hot sunny days when electricity demand is at its peak driven by air-conditioners.

Importantly, electricity is generated at the point of demand - where people live and work which means there is no need to transfer the energy long distances across expensive infrastructure.

Greenhouse gas savings

Solar power is a zero-emission electricity source. One megawatt hour of solar-derived electricity avoids approximately one tonne of CO2.

In Australia

Today solar PV power is installed on around 100,000 rooftops across Australia. At the end of 2008 we had over 100 megawatts of solar PV capacity installed nationwide - an increase of more than 25 per cent on the previous year and this figure has expanded rapidly since then.

Solar PV has a long history of supplying reliable ‘off grid’ power to remote and regional Australian communities. Around 70 percent of all PV installations are currently off-grid. However, with the introduction of recent government incentives, the number of grid-connected solar PV installations has grown and now accounts for about 30 percent of Australia’s total installed capacity.

Grid-Connected

Grid Connected Solar Power systems provide electricity for you home and feed excess power back into the Grid. This excess power is credited to your electricity account. In some states the State Govt has legislated a Feed in Tarif (FIT) that is larger than than than cost of the grid supply. This effectively means you are credited more to your account. This is generally advantageous, as often your electrical usage is lower during the day, when your may be at work or out of the home a lot, and not using much in the way of power.

In the evenings when you home is not Generating electricity, you draw down electricity from the Grid, as you did prior to installing a Solar Power system.

Off-Grid

Off-Grid systems are essentially the same as Grid-Connection, they used Photovoltaic panels, connected to an Inverter which converts DC current from the panels to AC current for your appliances. There is one major difference, power is stored in batteries, these batteries are used to provide electricity to your home when the sun is not shining, primarily at night.