About Solar PV
Solar panels convert sunlight to direct current (DC) electricity. These panels are typically roof mounted and are connected together to form a string or multiple strings. The solar panels are attached to an aluminium mounting system, which is secured to the roof (typically directly to the rafters) by specially designed brackets which fit under the tiles.
Each string that comprises the roof installation will have both a positive and negative connection that are usually run into the loft space. These will be connected to a DC isolator. This is essentially an on/off switch that can turn off (isolate) the DC supply from the panels. The DC supply is connected to an inverter. An inverter converts the DC electricity produced by the panels into alternating current (AC) which is required by household appliances and for export to the grid.
Another isolator is fitted to the AC side of the inverter. This enables the output from the inverter to be quickly switched off. In the event of a power cut the inverter is programmed to cut out automatically even though you may be generating solar electricity. This is for safety reasons, as the energy providers do not want electricity exported to the grid during a power cut as they will have engineers trying to fix the problem and do not want them to receive a nasty shock!
The AC supply from the inverter is measured by a dedicated generation meter. This is fitted near your consumer unit (fuse board) in a position that enables easy access for reading, as this meter shows how many kilowatt-hours of electricity you have generated and you will need to report this figure to your energy supplier to claim your Feed-in Tariff. From the generation meter the AC supply goes to a dedicated RCD protected isolation unit. This isolation unit will be connected directly to the incoming supply thereby avoiding any interference with your existing Consumer Unit. This switch is the main on/off switch for the PV System. There are no moving parts in the system, so its operation is silent and will give you many years of clean, green electricity generation.