How does Solar PV work?
Solar Photovoltaic (PV) systems consist of an array of panels that are either installed on roofs, walls, or can be ground mounted.
The solar panels comprise of solar photovoltaic cells which capture diffused solar radiation; this is light scattered by particles in the atmosphere
Photovoltaic (PV) cells are made from layers of semi-conducting material, usually silicon. As daylight falls on the cells the cells it creates an electric field.
As photons from daylight hit electrons in the PV panel, knocking them into a higher state of energy, they create electricity. Quite simply, the PV cells turn daylight directly into electricity.
Groups of cells mounted together called modules (panels).
Panels are connected together to form an array; the more panels you have in an array, the greater the amount of energy they can be produce
The power of a PV cell, or panel, or array, is measured in kilowatts peak (kWp).There are over 200 different makes of Solar PV panel on the market currently. Each manufacturer gives their panel a “w” (a watt) rating – i.e. the number of watts a panel will produce under peak “test” conditions. Typically panels range from 170w to 250w, with the “weakest and cheapest” panels being 170w, and the most powerful being 250w.
The amount of electricity generated is directly related to the amount of light that on the PV modules, Therefore Solar PV systems will be at their most efficient when under direct sunlight; however they will still produce electricity on overcast day without direct sunlight.
PV modules come in a variety of shapes, sizes, colours, efficiencies and costs.
PV modules produce a DC current which is not suitable for use with domestic appliance. Therefore the current enters an “inverter” which changes the DC current to an AC current which is suitable for use in homes and businesses.
The array is connected via a “Generation Meter” which measures and records how much AC power has been produced, which is used to calculate payments for the Feed in Tariff Scheme.
Via “Generation Meter” the electricity enters your fuse board.
You use the electricity as it is generated or it will automatically expert to the electricity grid network.
Currently most properties are not able to tell how much electricity they have used or how much they have exported to the grid; this requires a “Smart Meter” to be fitted.
Smart Meters are currently being installed in the UK as part of a national roll out which is expected to take up to 11 years. Because of this, the Government allows us to “assume” that you use 50% and export 50%. If you use more then you may want to install a Smart Meter.