What is Electric Power Plant?
Electric power generation - The power generation system is generally divided into three parts - electricity generation, transmission and distribution. Here we will discuss the power generation system. Generally, various natural energies are converted into electrical energy through conversion.
These natural energy sources can be divided into two categories -
- non-renewable sources
- and renewable sources
Currently, most electrical power is generated from non-renewable sources such as coal, oil and natural gas. But these sources are limited so we need to find alternative sources of power generation. Alternative sources are solar energy, wind, water, tides etc. These sources are eco-friendly and available for free.
Here the electrical power generation methods that use different types of energy will be discussed.
solar energy
It is one of the sources of alternative energy. There are two ways to generate electricity from sunlight -
We can generate electricity directly by using photovoltaic (PV) cell. Photovoltaic cells are made of silicon. A solar panel consists of a large number of photovoltaic cells.
We can convert sunlight into heat energy by using mirrors and convert this heat into steam and use that steam to turn turbines to generate electricity.
benefits of solar system
-Transmission cost is almost zero.
Solar power generation system is environment friendly.
- Low maintenance cost.
Disadvantages of Solar Power Systems
-The initial cost is high.
Large area required.
Solar power generation system is weather dependent.
Solar energy storage (battery) is expensive.
wind power
Air flows due to the change in temperature in the atmosphere. The energy of this air flow can be converted into electrical energy through a turbine. Wind spins the turbine at its own speed, the turbine is connected to a generator, when the turbine spins, the generator attached to it rotates to generate electricity.
Advantages of wind power systems
It is a free energy source.
- The operating cost is almost zero.
Disadvantages of wind power systems
It cannot produce the same amount of electricity all the time.
- Requires large open areas.
The process of making wind turbines is expensive.
-It gives low power output.
hydro power system
The energy obtained from the water of rivers or oceans is called hydroelectricity. Hydro power plants work on the basis of gravitational effect. In this process water gets stored in a dam or reservoir. When the dam is opened, water flows downstream, this water flows through penstocks or narrow pipes to set the turbines in motion, and the rotation of these turbines generates electricity.
Advantages of hydroelectric system:
Its cost in production system is very low.
At the end of this process the water can be used for irrigation and other purposes.
- Low maintenance cost.
-No fuel transportation required.
Disadvantages of hydroelectric systems
The initial cost of a power plant is high.
Hydro power plants are located in hilly areas and are far away from the load. Therefore, longer transmission lines are required.
-it depends on the weather.
coal power system
This electricity is generated by generating heat from the combustion of coal. This heat heats the water and turns into steam. This high pressure and high temperature steam flows into the turbine and spins the turbine to generate electricity. After passing through the turbine, the steam is cooled in a condenser and sent back to the boiler to form steam.
Advantages of coal power systems
Coal is cheap.
-Its starting cost is low.
- Requires less space.
Disadvantages of coal power systems
Coal is a non-renewable energy source.
Fuel prices are high.
Its smoke pollutes the aire
- It requires a lot of water.
nuclear power system
The production systems of a nuclear power plant and a thermal power plant are almost identical. A thermal power plant uses coal in boilers to generate heat and a nuclear power plant uses uranium in nuclear reactors to generate heat. In both power plants, thermal energy is converted into electrical energy. 1 kg of uranium can produce energy equivalent to burning 4500 tonnes of coal or 2000 tonnes of oil.
Advantages of Nuclear Power Systems
It requires less space than thermal power plant and hydroelectric plant.
- It does not emit CO2.
Less space required.
- Disadvantages of nuclear power systems
-Its initial construction cost is high.
Its operation and maintenance cost is high.
It contains radioactive waste.
- There is danger of explosion.
How does a turbine work in a power plant?
Hydroelectric power plants (like ours) use the potential energy of water to drive turbines. Simply put, the water is held at a high point (relative to the turbine). This is done by building a dam. When water is allowed to fall from that high place, it falls with great speed. This water flows and spins the turbine wheel. The turbine then starts rotating and the generator shaft is connected to the turbine shaft. So the generator also spins and current is generated.
A thermal power plant consists of a boiler that converts water into steam. This steam is driven into the turbine at high velocity. This steam spins the turbine and the turbine turns the generator. In this way current is created.
Nuclear power plants have nuclear reactors instead of boilers. Nuclear fission reaction takes place in this reactor.
transmission and distribution
"Some Simple Concepts of Transmission and Distribution"
Large networks of transmission cables are used to carry electricity from generating stations to residential buildings.
Transmission lines are large electrical networks used to transport high power from generation stations to various substations.
Distribution is the electrical network which is used to distribute electricity from the sub-station to the subscriber end i.e. residential areas.
-Electrical power transmission and distribution can be either AC (Alternating Current) or DC (Direct Current) in overhead/underground systems.
Overhead transmission and distribution system is common almost everywhere in Bangladesh.
AC system for production and distribution and DC system for transmission is the best method. AC is mainly used in long distance transmission for two reasons. Firstly - AC voltage can be easily increased or decreased as required with the help of transformer. For example, a step-down transformer can be used to convert a 400,000 volt transmission line to 220 volts for home use. The second reason is that the transmission loss is much lower when AC is used at higher voltages for transmission.
feeder
Now let us see what is a 'feeder' and what is its function
Feeder is an unused line constructed to supply electricity from high voltage substations or grid substations to various load centers for the purpose of supplying electricity to populated areas, factories or residential areas.
The thicker conductors connected to the generating station are called feeders, in which there is no tapping. On the other hand, the tapped conductor connecting to the customer's service mains is called distributor, which keeps changing the value of current along its entire length.
Service mains are relatively thin cables through which electricity is delivered to customers. It is connected with the distributor. But the distributor is directly connected to the feeder.
