Solar electricity is the same as your regular main supply but because it’s generated from sun light. It’s clean, silent and is an inexhaustible supply.
“The sun delivers enough solar energy to earth in 15 minutes to supply the whole world with energy for year.” PV* or photovoltaic modules convert light into dc electricity. An inverter changes the dc electricity into ac electricity so that we can use it in our homes for cooking and lighting etc. The correct technical term for this process is Photovoltaic – or PV for short. The simplest and most cost effective systems consist of a number of PV modules mounted on the roof or onto a frame on the ground.
What is a Photovoltaic module?
PV modules are made up of specially coated Silicon cells. As light falls on these cells electrons rush from one side of the silicon to the other and an electrical current is created. The more cells there are the more current is generated. When the right number of modules are linked together enough voltage is created to match the system voltage with the mains or grid.
Module type & performance:
Poly Crystalline PV modules rated at 1 kW will generate approximately 750-850kWh per year in the North East climate*, provided the array is south facing and un-shaded. Poly Crystalline modules are the most commonly used. Poly Crystalline means that the silicon cells are cut from a block made from many pieces of silicon. They have a blue-flecked appearance. Most manufacturers offer Poly Crystalline modules. Mono Crystalline PV modules rated at 1 kW will generate approximately 850kWh per year. Mono Crystalline modules usually have a white diamond shape between the cells. Mono Crystalline means the silicon cells are cut from a single block of silicon. They are the longest lasting module, most 40 year old Mono Crystalline modules still function at 75% power.
Hybrid PV modules rated at 1 kW will generate over 900kWh per annum. Hybrid modules comprise a mono crystalline cell with a thin amorphous layer – they are up to 12% more efficient. They have the highest power to area ratio on the market so they are an obvious choice for roofs where space is at a premium.
How the PV system works
The electricity generated by the PV modules is converted from DC to AC by an inverter and connected to your consumer unit. The electricity flows to wherever it is needed to power your appliances. At times when there is more electricity being generated than is needed – it will flow out through an export meter into the grid to be used locally by your neighbors. The meter records the exported electricity and the exported units can be sold to a number of electricity supply companies.
The “clean” solar electricity is always used in priority over electricity from the grid. When the solar panels can’t generate sufficient electricity – at night, for example – electricity is drawn from the grid in the normal way, so you will never be without electricity.
