How it works
A solar panel system comprises of photovoltaic (PV) panels and one or more inverters. The panels are mounted on framework connected to the roof structure; alternatively they can be mounted on the ground.
Solar panels comprise of many, smaller units called PV cells. The cell is made up of two layers of semi-conducting material, usually silicon. The panels generate power by allowing photons, or particles of light, to knock electrons free from atoms, generating a flow of electricity. To generate electricity PV cells need to establish an electric field.
To construct a field, manufacturers “dope” silicon with other materials, giving each side of the cell a positive or negative electrical charge. Specifically, they seed phosphorous into the top layer of silicon, which adds extra electrons with a negative charge to that layer. The bottom layer uses boron, which results in fewer electrons, or a positive charge. This makes an electric field at the junction between the silicon layers. When a photon of sunlight knocks an electron free, the electric field will push that electron out of the silicon junction. Metal conductive plates on the sides of the cell collect the electrons which then flow through cables connecting the panels together in an array.
The cells don’t need direct sunlight to work – they can still generate electricity on a cloudy day, albeit not as much. When daylight hits the cells it creates the electric field – the brighter the sunlight, the more electricity is produced. This direct-current (DC) electricity then flows to the inverter(s), which converts it into alternating-current (AC) electricity to be used within the connected building(s).
During the day when solar panels are generating electricity, the power will automatically feed anything connected to your fuse board including machinery, appliances, lighting, etc. When the property’s power consumption is greater than the PV system is generating, i.e. peak demands or after sunset, you will purchase from the grid in the traditional way. Similarly, as solar panels produce electricity when the sun is shining – which does not necessarily correlate with the building’s usage – it is sometimes necessary to export the excess power back to the grid. Alternatively, a battery system can be utilised to store the excess energy and use it later in the day or at night.
How it works