We divide the power system into three parts; power generation, transmission and distribution. In this article, we will discuss power generation. Actually, in power generation, one form of energy gets converted into electrical energy. We produce electrical energy from various natural sources. We classify these sources into two types renewable sources and non-renewable sources. In present power system, most of the electrical energy gets generated from non-renewable sources like coal, oil and natural gases. But these sources are limitedly available. So, we have to use these sources carefully and always to find an alternate source or move on renewable sources. The renewable sources include the solar, wind, water, tidal and biomass. These sources are the environment-friendly, free and infinite resource available. Let us get more information about renewable sources.
Solar Energy System
It is a best alternative source for power generation. There are two ways, to generate electrical energy from sunlight.
- We can create electricity directly by using photovoltaic (PV) cell. The photovoltaic cell is made up of silicon. Many cells are connected in series or parallel to make a solar panel.
- We can produce heat (solar thermal) with the help of mirrors in the sunlight, and we use this heat to convert water into steam. This high-temperature steam rotates the turbines.
Advantages of Solar Energy System
- Transmission cost is zero for a stand-alone solar system.
- Solar electricity generation system is environment-friendly.
- Maintenance cost is low.
- It is an ideal source for remote locations that cannot link to the grid.
Disadvantages of Solar Energy System
- Initial expenses are high.
- Require large area for bulk production.
- Solar electricity generation system is weather dependent.
- Solar energy storage (battery) is costly.
Wind Energy System
Wind turbines are used to convert wind energy into electrical energy. Wind flows due to temperature change in atmosphere. Wind turbines turn wind energy into kinetic energy. The rotating kinetic energy rotates the induction generator, and that generator converts kinetic energy into electrical energy.
Advantages of Wind Energy System
- Wind energy is an unlimited, free and clean source of energy.
- Operating cost is almost zero.
- A wind electricity generating system can generate power in a remote location.
Disadvantage of Wind Energy System
- It cannot produce the same amount of electricity for all time.
- It needs a big open area.
- It makes noise.
- The construction process of a wind turbine is expensive.
- It gives lower electricity output.
- It poses threats from flying birds.
Hydro Energy System
The power obtained from river or ocean water is called hydro power. Hydro power plants are works based on the gravitational effects. Here we store water in a dam or reservoir. When we allow falling the water, the movement of this water as it flows downstream towards the penstock causes kinetic energy that rotates the turbines.
Advantages of Hydro Energy System
- It can be used in the service instantly.
- After this process, water can be used for irrigation and other purposes.
- Dams are designed for an extended period and so it can contribute to the generation of electrical energy for many years.
- Running and maintenance costs are low.
- No fuel transportation is required.
Disadvantages of Hydro Energy System
- The initial cost of a hydel power plant is high.
- Hydro power plants are located in the hilly area, and it is very far from the load. So, they require long transmission line.
- Construction of dams can flood towns and cities.
- It is also weather dependent.
Coal Energy System
Thermal power plant produces electricity by burning coal in the boiler. Heat is used to convert water into steam. This high pressure and high-temperature steam flowing into the turbine spins a generator to produce electrical energy. After it passes through the turbine, the steam gets cooled in a condenser and reuse in the boiler to generate steam again. Thermal power plant works according to Rankine cycle.
Advantages of Coal Energy System
- Coal is cheap.
- It has less initial cost compared to renewable power plants.
- It requires less space than a hydel plant.
- We can construct a thermal power plant at any place because coal can be transport to the plant irrespective of its location.
- Construction and commissioning of thermal power plant take lesser time than a hydel plant.
Disadvantages of Coal Energy System
- Coal is a non-renewable energy source.
- Operating cost high and variable according to the price of fuel.
- It pollutes the atmosphere due to smoke and fumes.
- It requires huge quantity of water.
Nuclear Energy System
Working of nuclear power is almost same as a thermal power plant. In a thermal power plant, coal is used in the boiler to produce heat. In a nuclear power plant, uranium is used in the nuclear reactor to generate heat. In both power plants, heat energy gets converted into electrical energy.
1kg of uranium can produce energy same as the energy produced by burning of 4500 tonnes of coal or 2000 tonnes of oil.
Advantages of Nuclear Energy System
- It requires less space than a thermal power plant and a hydro power plant.
- It can produce an unusually high amount of electrical energy from the single plant.
- It does not emit CO2
- A nuclear power plant needs a small quantity of fuel.
Disadvantages of Nuclear Energy System
- It has high initial construction cost.
- It has high operating and maintenance cost.
- It has radioactive waste.
- It has a high risk of radio-activity and explosion.
Installed Electric Capacity in India
Yearly gross electricity generation by source (GWh) (2016-2017)