Stand Alone vs. Grid Tied PV systems
A Solar Photovoltaic (PV) system is able to supply electrical energy to loads by directly converting solar energy through the photovoltaic effect. The system structure is very flexible. PV modules are the main building blocks and can be arranged into arrays to obtain different levels of power production. Other components include the charge controller, battery bank, Inverter and balance of system components. The system is designed taking into consideration the energy needs or loads for a particular application. The two major classes of PV systems are:
The system includes all the elements necessary elements to supply AC appliances in a household or commercial application. A diesel generator may be considered to enhance the system reliability but is not compulsory. The number of components in the system will depend on the type of load that is being served.
Grid Tied PV Systems are directly coupled to the electrical distribution network and may not require battery storage as shown on the diagram below. Electrical energy is either sold or purchased from the electric utility company depending on the energy load patterns and the solar energy resource variation during the day. An inverter is needed to convert DC to AC.
There are many benefits that could be obtained from grid-tied PV systems instead of standalone systems such as less balance of system components needed, eliminates the need for energy storage and takes advantage of existing electrical infrastructure