How a generator works to create electricity

How a generator works to create electricity

How a generator works


Generator is an important device that ensures continuous business operations even after power outages.

It works on the principle of Michael Faraday an English scientist who discovered electromagnetic induction, diamagnetism and electrolysis.

Here is how a generator works, its main components and how a generator operates as a secondary source of electrical power in residential and industrial settings.

An electric generator works by converting mechanical energy obtained from an external source into electrical energy as the output. This does not mean that generators create electricity. No. On the contrary a generator works by using mechanical energy supplied to it to force the movement of electric charges present in the wire of its windings through an external electric circuit.

This flow of electric charges constitutes the output electric current supplied by the generator. This mechanism can be understood by considering the generator to be analogous to a water pump, which causes the flow of water but does not actually ‘create’ the water flowing through it.

So how does a generator works? A Generator works on the principle of electromagnetic induction that was discovered by Michael Faraday a British scientist in 1831-32. The reknowned inventor created the first electric generator, called the dynamo, as well as the first electric motor To understand how a generator works to produce electricity, it is imperative that we look at its various components.

The control Panel

This is the user interface of the generator and contains provisions for electrical outlets and controls.

Battery Charger
The generator works by starting its battery. The battery charger keeps the generator battery charged by supplying it with a precise ‘float’ voltage. If the float voltage is very low, the battery will remain undercharged. If the float voltage is very high, it will shorten the life of the battery. Battery chargers are usually made of stainless steel to prevent corrosion.

They are also fully automatic and do not require any adjustments to be made or any settings to be changed. The DC output voltage of the battery charger is set at 2.33 Volts per cell, which is the precise float voltage for lead acid batteries. The battery charger has an isolated DC voltage output that does interfere with the normal functioning of the generator.


The engine is extremely important because it is actually the source of the input mechanical energy to the generator. The larger the engine the higher the output a generator can supply and vice versa.

The alternator, also known as the ‘genhead’, is the part of the generator that produces the electrical output from the mechanical input supplied by the engine. It contains an assembly of stationary and moving parts encased in a housing. The components work together to cause relative movement between the magnetic and electric fields, which in turn generates electricity.

Fuel System
The fuel tank usually has sufficient capacity to keep the generator operational for 6 to 8 hours on an average. In the case of small generator units, the fuel tank is a part of the generator’s skid base or is mounted on top of the generator frame. For commercial applications, it may be necessary to erect and install an external fuel tank. All such installations are subject to the approval of the City Planning Division.

Cooling & Exhaust Systems

(a) Cooling System
Continuous usage of the generator causes its various components to get heated up. It is essential to have a cooling and ventilation system to withdraw heat produced in the process.

Raw/fresh water is sometimes  used as a coolant for generators, but these are mostly limited to specific situations like small generators in city applications or very large units over 2250 kW and above. Hydrogen is sometimes used as a coolant for the stator windings of large generator units since it is more efficient at absorbing heat than other coolants.

Hydrogen removes heat from the generator and transfers it through a heat exchanger into a secondary cooling circuit that contains de-mineralized water as a coolant. This is why very large generators and small power plants often have large cooling towers next to them.  For all other common applications, both residential and industrial, a standard radiator and fan is mounted on the generator and works as the primary cooling system.

It is essential to check the coolant levels of the generator on a daily basis. The cooling system and raw water pump should be flushed after every 600 hours and the heat exchanger should be cleaned after every 2,400 hours of generator operation. The generator should be placed in an open and ventilated area that has adequate supply of fresh air. The National Electric Code (NEC) mandates that a minimum space of 3 feet should be allowed on all sides of the generator to ensure free flow of cooling air.

(b) Exhaust System
Exhaust fumes emitted by a generator are just like exhaust from any other diesel or gasonline engine and contain highly toxic chemicals that need to be properly managed. Hence, it is essential to install an adequate exhaust system to dispose of the exhaust gases.  This point can not be emphasized enough as carbon monoxide poisoning remains one of the most common causes for death in post hurricane affected areas because people tend to not even think about it until it’s too late.

Exhaust pipes are usually made of cast iron, wrought iron, or steel. These need to be freestanding and should not be supported by the engine of the generator. Exhaust pipes are usually attached to the engine using flexible connectors to minimize vibrations and prevent damage to the generator’s exhaust system.

The exhaust pipe terminates outdoors and leads away from doors, windows and other openings to the house or building. You must ensure that the exhaust system of your generator is not connected to that of any other equipment. You should also consult the local city ordinances to determine whether your generator operation will need to obtain an approval from the local authorities to ensure you are conforming to local laws a protect against fines and other penalties.

Lubricating System
A generator consists of moving parts in its engine this then requires that requires that the parts are lubricated. This ensures not only durability but also durability but also smooth operations for a long period of time. The generator’s engine is lubricated by oil stored in a pump.

Finally, it is important to maintain a generator to make it last longer and work smoothly.

The animation below shows how a generator works.