AC Electricity Generation

AC electricity generation involves the conversion of other types of energy into alternating current (AC), using a turbine and a generator. Then it is distributed so that people can use it at home and industry employ it in factories to power electrical gadgets.

In AC electricity generation, either the potential energy of flowing/falling water or the chemical energy contained in fuels, such as natural gas or diesel, is transformed into mechanical rotatory energy by the turbine. The flowing water or the combustion of fuel in a chamber make the turbine rotor revolve at great speed. The axle of this revolving machine is coupled to a generator rotor shaft.

The generator consists of a stator and a rotor. The turning rotor winding produces a powerful magnetic field, which alternates its polarity in fraction of a second. This alternating magnetic field in turn induces AC electricity in the stator winding. The high-voltage alternating current electricity is then sent to a nearby electrical substation, where step-down transformers reduces and levels the voltages so that AC current can be used by people at their homes. You must bear in mind, that it is a universal law of physics that AC electricity is always induced in a metal wire when it is exposed to a magnetic field that constantly changes polarity (this was observed and discovered by Michael Faraday).

The electromagnet and the enameled wire is installed on the rotatory axle (or shaft) of a generator. This rotating part is called “rotor”, which induces alternating current on the static part of the generator, which is called “stator” and consists of a multi-grooved round steel casing in which enameled copper wire is wound along these inner grooves. But why is it called “alternating”? Because the rotating magnet of the generator rotor constantly alternates or changes polarity, going form positive to negative to positive to negative, and so forth; this induces a flow of electrons along the enameled copper wire on the stator that alternates the flow direction as the magnet changes polarity, going in one way, then in the other as in waves.

But, what makes a generator shaft rotates, so that it can generate AC electricity? For that we need either an internal combustion engine or a turbine, coupling its shaft to the generator’s. We know that the engine is powered by gasoline or diesel, but when these flammable fluids are expensive or absent, we have to put the engine aside and use a turbine. What powers the turbine? Different alternative sources, such as steam, gas, falling water, or wind. Steam is the most widely used source of energy to power turbines in AC generation in power plants in the United States and Europe. But steam has to be obtained and pressurized from boiling water in a boiler and, for this, we also need fuel, such as coal, wood, gas, and nuclear uranium rods in a controlled fission nuclear power plant. Is there any other way to produce the needed heat to get steam from water? Fusion.

In the late 19th century, when Nicola Tesla and George Westinghouse demonstrated that alternating current (AC) was cheaper to produce and easier to distribute to houses and factories than direct current (DC), the AC generation industry took off as hundreds of power plants began to spring up throughout the United States. But what is essentially needed to generate alternating current and why it is called “alternating”? Basically three things are needed: a magnet (or electromagnet), enameled wire, and a rotatory axle.