The simplest answer to this common question is that a generator works by converting mechanical (or kinetic) energy into electrical energy. This is true of huge generators at power plants, commercial backup generators, and small, portable models.
Using a generator does not mean you’re creating energy. The Law of Conservation (one of physics’ major laws) states that it’s in fact impossible to create or destroy energy. Instead, we’re constantly shifting energy into different forms to suit our needs.
Generators convert mechanical energy into electrical energy using electromagnetic induction. In its simplest form, electromagnetic induction uses a magnet to move electrons within a conductor, such as a copper wire.
A generator’s engine uses fuel, whether diesel, gasoline, propane, or natural gas, to create mechanical energy, which is then converted to electrical energy within the generator’s alternator. Mechanical energy from the engine is used to move a wire coil within a magnetic field or move a magnetic field around a stationary set of wires in the alternator. This magnetic field is produced either using a physical magnet or a magnetic field created by induction.
The electrical energy created in the alternator is measured in volts. A voltage regulator takes the “new” electrical energy and regulates how much voltage passes to your home or business. It does this with a cycle of AC to DC conversion that encourages the production of more or less energy to power the required load.
Another output of the electromagnetic induction that occurs within a generator is heat. A voltage regulator helps reduce heat production by also reducing electrical output when possible. The byproduct of heat is removed from the generator using a cooling system. In small generators, this may be a simple air intake. In commercial standby generators, water and/or hydrogen are coupled with a heat exchanger to remove excess heat.
Tips on choosing a generator
We understand that figuring out which generator to buy is no mean feat. There’s a huge range of options to explore, from 2 kW diesel generators to small petrol models, big generators for the home to those for sensitive equipment. Whether you’re looking for a model that can keep up on the job site or the best generator for home use, we’re here to help. We’ve spent some time putting together a simple checklist of considerations, so you know what to look for when buying a generator.
Wattage – It’s important to consider wattage before you buy. You need to determine exactly how much power you’ll require for the items you wish to run.
Domestic or professional – Some generators are designed specifically for hobbyists and leisure use; others are perfect for workshops and commercial use.
Equipment – Do you want to run sensitive equipment such as computers or televisions straight from your generator? We have a range of inverter generators for sensitive electronics.
Petrol or diesel – You need to consider the total cost of ownership when investing in a new generator. With a comprehensive range of the best diesel generators and petrol models on the market, you’ll be able to pick the most cost-efficient fuel source for your power requirements.
Outdoor Use – You may want to use your generator outside for activities such as camping. Find out how you can tell if a generator is weatherproof and whether it's appropriate to use in wet conditions.
Standby & Specialist Generators – Do you want a backup power supply for your home? Or perhaps you need a specialist generator for industrial projects? Find out more about specialist and standby generators for home use.