Power Generation: Types of Power Plants and Generators
Electric Generator
Transforms mechanical energy into electricity. Generators produce electricity from the motion of a conductor in a magnetic field created by a magnet or an electromagnet.
Consists of two main parts:
- Stator: A fixed part containing a metallic core with copper wires.
- Rotor: A moving part that rotates around an axis, containing circuitry that becomes electromagnets when subjected to an electric current.
Non-Nuclear Power Plants
In these plants, mechanical energy to move turbines, connected to the generator rotor, comes from heat energy in water vapor pressure after heating in a large boiler.
The fuel used to produce water vapor determines the type of power plant: oil, natural gas, or coal.
Water vapor, heated to 600 ºC, is pumped at high pressure into a turbine, making it turn. This produces mechanical energy, which is then transformed into electrical energy by a generator coupled to the turbine.
Nuclear Power Plants
These power plants replace the boiler with a nuclear reactor. The main advantage is profitability in energy production. However, drawbacks include managing radioactive waste and the risk of potential nuclear accidents.
Water vapor production is based on heat released by the fission of radioactive element nuclei.
Biomass Power Plants
Biomass consists of organic compounds produced by natural processes.
Biomass energy comes from vegetation, forest and agricultural residues, or specific crops like sunflower and beets.
Biomass can also be used through physical and natural chemical processes in plants, called digestion, leading to fuels like charcoal, alcohol, or biogas.
To produce steam, biomass fuel is burned, moving a turbine connected to a generator, thus producing electricity.
Hydraulic or Hydroelectric Plants
These plants use the potential energy of water impounded by dams. When water is released, this energy converts into kinetic energy, moving the blades of a turbine at the dam’s base, which is connected to the rotor shaft of a generator. This transforms kinetic energy into electric power.
Hydroelectricity is divided into two types based on water usage:
- Hydro-gravity: Water from a river is used and not returned.
- Central hydraulic pump: Water falls to a lower reservoir, then is pumped back to the upper reservoir for reuse.
Wind Power
Wind plants or wind farms use wind kinetic energy to move the blades of an engine on top of a tower.
The blades are connected to a speed multiplier, whose output is fixed to the rotor shaft. Wheel bearings are typically used to increase the speed of entry when turning.
Solar Power
Solar power uses energy from the sun. There are two types:
Photothermal: Solar radiation heats water in a boiler. The steam produced moves the rotor of a generator.
- Photovoltaic: Solar radiation is converted into electricity through photovoltaic panels.