22 GENERATORS A generator is a device used to produce electrical energy, which can be either stored in batteries or supplied to homes, shops, and offices through the power grid. How do generators work? Electric generators work on the principle of electromagnetic induction. A coil made of conducting material, usually copper, wound onto a metal core, is rotated rapidly between the makes it rotate. The mechanical energy required for the rotation can be provided by engines operating on fuels, such as diesel, petrol, natural gas, or by renewable energy sources such as wind turbines, water turbines, or solarpowered turbines. Applications of electric generators Generators are employed: in power stations, as they provide the power that is then distributed to users through the power grid; in places where interruptions in the power supply are frequent, so they can be used as a backup; poles of a magnet. When the coil rotates, the magnetic field interferes with the electrons in the conductor and induces a flow of electric current inside it. The coil together with its core is known as armature. The armature is connected to the shaft of a mechanical energy source, such as a motor, which fuel: carburante power grid: rete di distribuzione elettrica power station: centrale elettrica shaft: asse to wind: avvolgere 60 elecTriciTy in isolated areas, where electricity from the main line cannot be accessed; when working in places where electricity cannot be accessed from the grid. AC and DC generators Generators can produce electricity either in the form of alternating or direct current. Generators producing alternating current, also called alternators, are mainly employed in power plants to produce electricity which will be distributed through the grid. Generators producing direct current, also called dynamos, are mainly employed for battery recharging.