Generators provided by are used to convert electrical power into an alternative form. This may be mechanical energy or even a different form of electricity. A generator forces an electric charge to move through an external circuit without creating electricity or charge. It is alike to a water pump whereby it creates a flow of water but does not produce the water inside. There are various different kinds of generators available, some of the more common ones are petrol, and diesel. Petrol generators combine an electrical generator with an engine which are fitted together to form a single piece of equipment. In addition to the engine and generator, petrol generators have a fuel supply, a constant engine speed regulator, cooling and exhaust systems, and lubrication system.

A diesel generator combines a diesel engine with an electrical generator (often referred to a as an alternator) to create electric energy. Diesel generating sets are typically found in places that do not have connection to the power grid or, alternatively as an emergency power-supply if the grid fails. If one or more diesel generators are operating without a connection to an electrical grid they are said to be operating in “island” mode. Several parallel generators working together in this way provides an advantage of redundancy and better efficiency at part loads.

Diesel generators can be connected together electronically through synchronization. This refers to a process which involves matching the voltage, frequency and phase before connecting the generator to a live bus-bar. This can be done automatically by an auto-synchronizer module. The load can be shared among parallel running generators through load sharing. As the prime mover of a diesel generator runs at constant speed, it will take more load when the fuel supply is increased. The load will be released if the fuel supply is decreased.