There are two general categories of PV systems:
- Grid-connected PV systems, which are connected to the electric grid
- Off-grid PV systems, which are not connected to the electric grid
Left: Grid-connected systems feed electricity into the national electricity grid. Right: Off-grid systems produce electricity that is consumed on site.
The two principal categories of grid-connected and off-grid systems also have further sub-categories. The overwhelming majority of systems will fall into the above categories. To understand how a solar system functions, it is essential to be clear about which type of system is being considered.