How do photovoltaic (PV) panels work?
Sunlight is made up of photons, and when it hits the semi-conductor metal of the PV panel, electrons are released; these electrons form a direct current. People have been using PV for years; your pocket calculator for example typically has a number of PV cells. NASA has been using and developing this technology for years, satellites and other space going bodies rely on this technology to produce the power in order to run.
A typical solar PV systems consist of three main elements:
- an array of solar PV modules
- an inverter(s)
- cables, display and switchgear
The inverter is an electronic device that converts the DC electricity produced by the solar array into AC with the same voltage and frequency as the mains supply. The inverter also performs various safety functions, constantly monitoring the grid and switching off in the event of a fault or major fluctuation in mains supply.
The output of the inverter goes directly into the building’s fuse box – feeding solar electricity into the building’s conventional electricity supply which means you will not have to buy so much electricity from your electricity supplier.
The appliances in the building will use the free electricity generated from your solar PV system and any surplus power will automatically be exported into the grid so that others can buy the “green” electricity you have generated
Most solar PV systems are grid connected, which means that the electricity generated is fed directly into (and synchronised with) a building’s existing mains supply. On a sunny day, the power generated by the solar PV system reduces the amount of electricity that needs to be bought from the electricity supply company. On very sunny days, or at times when not many loads are turned on, the PV may generate more power than is needed in the building, and the surplus will be exported out into the grid.