What is Solar PV ?
Solar PV is also known as Photovoltaics or solar electricity. It’s the same as the regular mains supply, but because it’s generated from sun light, its clean, silent and from an inexhaustible supply. *The correct technical term for this process is Photovoltaic – PV for short. PV* modules convert light into dc electricity. An inverter changes the dc electricity into ac electricity allowing us to use it in our homes for cooking and lighting etc.
“The sun delivers enough solar energy to earth in 15 minutes to supply the whole world with energy a for year.”
The simplest and most cost effective systems consist of a number of Solar PV modules mounted onto a roof.
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 kWp will generate between 800-1100kWh per year depending on your location in the UK* - provided the array is south facing and un-shaded.
Poly Crystalline are the most commonly manufactured modules. Poly Crystalline means that the silicon cells are cut from a block made from many pieces of silicon. These have a blue appearance and perform well in the UK climate.
Mono Crystalline PV modules rated at 1 kWp generate similar kWh yields to poly crystalline
They usually have a white diamond shape between the cells. Mono Crystalline means the cells are cut from a single block of silicon.
Hybrid PV modules rated at 1 kWp will generate over higher kWh yields. E.g. Sanyo HIP
Hybrid modules comprise of a mono crystalline cell with a thin amorphous layer making them up to 12% more efficient but with a much higher price tag.. They have the highest power to area ratio on the UK market, so they are a good choice for roofs where space is limited.
The ideal site will be within 40 degrees of south. The Ideal pitch is around 30 degrees.
Sites that face 90 degrees from south will suffer approximately 10% reduction in performance.
*These figures are based on experience from previous installations and are not a guarantee of how much energy a given system will yield in a given year.