Electrical Power Generation

Electric Power Generation is the method of generating electrical power from primary energy sources. It is the first step of the electrical power cycle (The other ones being transmission, distribution, analysis, operations, and control).

Electrical power is not directly available in nature. Instead, it should be generated by converting other forms of energy to electricity. The assembly where power is generated is known as the power plant. Principally, each power plant has electromechanical generators synchronized to and driven by turbines or engines. Besides traditional power plants, wind farms, photovoltaics, and geothermal power sources are also in practice.

Renewable vs. Non-Renewable Power Generation Sources

Electric Power Generation can be broadly classified into two categories based on the natural sources from which power is generated.

Renewable power sources are the sources that will naturally refill over time. Examples of such sources include wind, solar, plants, and trees.

Non-Renewable Power sources are sources that are one-time use and are gone forever once utilized. Examples of such sources include fuels and coal.

3 Different Methods of Power Generation

Electrical power can be created from a variety of different methods. The three most popular methods of obtaining electricity are:

  1. From Synchronous Generators
  2. Form Solar Cells
  3. From Batteries or Fuel Cells

Synchronous Generators or Alternators

The working principle of a generator is based on the fact that a moving wire in the presence of a magnetic field has a voltage induced in it. 

The principle is used for generating electricity. All types of power stations generate power using the same rule. All these power stations have a prime mover coupled to the generator for power generation. Depending on the form of energy that is to be converted to electricity, power generation units are divided into five categories:

  1. Diesel power station: A diesel power plant employs a diesel engine as the prime mover. Inside the engine, diesel is burnt, and combustion products act as the working fluid for creating mechanical energy. The diesel engine is synchronized to the alternator and drives it.
  2. Hydroelectric power stations: A hydropower plant uses a water turbine as the prime mover. Water is stored at a high level and allowed down to the turbine. The turbine rotates the alternator, which converts mechanical energy to electrical energy. 
  3. Nuclear power stations: A nuclear power station employs steam turbines. Steam generated in the heat exchanger leads to the steam turbine. The steam turbine is synchronized to the alternator and drives the alternator, which converts mechanical energy to electrical energy.
  4. Steam power stations: Here, the prime mover is a steam turbine. In this power station, the heat energy of coal is converted to electric power. Steam is produced in a boiler using heat energy; this steam is then supplied to the steam turbine that is synchronized with an alternator and generates electric power at the output.
  5. Wind power station: A wind turbine comprises a propeller-like blade. The wind turns these blades around a rotor that spins the linked generator and produces electricity at the output.

Power Generation from Solar Cells

Apart from conventional methods, power can be generated using solar cells. The phenomenon referred to as the photovoltaic effect is a combined physical and chemical phenomenon in which sunlight is converted into DC electricity.

Power from Batteries

Electric power can also be generated from batteries using the electrochemical process.

Equipment used for Power Generation

The schematic arrangement of power stations varies from each other. Each type of power station has its unique layout and structure of equipment. However, all power stations employ a generator and some prime mover.

Synchronous Generator: Synchronous generator or alternator is AC electrical machine used to convert mechanical power to electrical power.

Turbine: The turbine in a power station is responsible for driving the alternator. All commercial power plants utilize some turbine in their operations. Based on the type of power plant, there are four types of turbines.

  1. Steam turbines
  2. Natural gas turbines
  3. Hydro turbines
  4. Wind turbines

Transformer: The transformer is an electrical device that transforms ac electrical power from one voltage level to another. In a power station, electrical power is generated at comparatively lower voltage levels ranging between 12 to 28 kV. Transferring electricity at such levels is relatively inefficient. It is, therefore, essential to use an appropriate transformer to increase the power for transmission purposes. The transformer used at the substation is known as a unit transformer, and its primary role is to step up the voltage to transmission level voltages.

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