Comparison of Various Power Plants

Modern society cannot function without a reliable power system. We need energy for all our activities, and we utilize this energy in various forms such as thermal, electrical, mechanical etc. However, electrical energy can be considered as the most important of these since we can generate, transmit, distribute, convert and utilize it efficiently and economically.

The generation aspect is at the foremost of the chain and it is realized with the help of power plants. A set of equipments utilized to produce electrical power in large quantities (usually hundreds - thousands of MW) is called a generating station or a power plant. Such a power plant will convert one form of energy (nuclear, thermal, hydro, solar etc.) to electrical energy.

On the basis of this form of energy conversion, power plants are broadly classified as follows:
  1. Thermal Power Station (Steam power plant)
  2. Hydroelectric Power Station
  3. Nuclear Power Station
There are other plants too, such as:
  • Solar Power Plant
  • Wind Power Plant
  • Tidal Power Plant
  • Geothermal Power Plant
  • Diesel Power Plant
However, they represent only a small part of the global scheme in terms of capacity and utilization.
comparison of various power plants

Each of these power plants has its own set of features, requirements, advantages and disadvantages. They can be compared on the basis of several parameters. The salient points are given below:

Thermal Power Station

Principle of operation: It works on Modified Rankine Cycle.

Location: It is located at a site where coal, water and transportation facilities are available easily. It is located near load centers.

Requirement of Space: Need a large space due to coal storage, turbine, boiler and other auxiliaries.

Efficiency: Overall efficiency is least compared to other plants. (30%-32%)

Fuel Used: Coal (mostly) or oil.

Availability of Fuel: Coal reserves are present all over the world. However, coal is non-renewable and limited.

Cost of Fuel: High. Coal is heavy and has to be transported to the plant.

Initial Cost of Plant: Lower than Hydroelectric and Nuclear power plants.

Running Costs: Higher than Hydroelectric and Nuclear power plants.

Maintenance Costs: High. Skilled engineers and staff are needed.

Transmission and Distribution Cost: Low. It is usually located near load centers.

Start-up Power: About 10% of unit capacity.

Starting time: Large

Standby Losses: More than hydroelectric and nuclear power plants. Boiler flame has to be kept burning, so some amount of coal is used constantly, even when the turbine is not in operation.

Cleanliness: Less clean. Smoke and ash are produced.

Environmental Considerations: Air pollution occurs and leads to acid rain. Greenhouse gases are also produced.

Life Time: 30 - 40 years.

Hydroelectric Power Plant

Principle of operation: Potential energy of water is converted to Kinetic energy and used to rotate a turbine.

Location: Located where a large amount of water can be collected easily in a reservoir by constructing a dam. Usually in a hilly area at high altitude.

Requirement of Space: Very large space required. A dam is huge.

Efficiency: As high as 85% to 90%

Fuel Used: Water

Availability of Fuel: Availability of water is unreliable because it depends on the weather (rainfall.)

Cost of Fuel: Water is free.

Initial Cost of Plant: Very high. Construction of a dam and reservoir is expensive.

Running Costs: Zero, because no fuel is needed.

Maintenance Costs: Low.

Transmission and Distribution Cost: High. It is located in remote areas, away from load centers.

Start-up Power: 0.5% to 1% of unit capacity.

Starting time: Low. Can be started instantly.

Standby Losses: None.

Cleanliness: Clean.

Environmental Considerations: Affects marine life. People in the region have to be relocated.

Life Time: Large (50 to 100 years.)

Nuclear Power Plant

Principle of operation: Thermonuclear fission.

Location: Located away from heavily populated areas.

Requirement of Space: Requires minimum space compared to other plants of the same capacity.

Efficiency: Higher than Thermal Power Station. About 55%

Fuel Used: Uranium (U235) and other radioactive metals.

Availability of Fuel: Deposits of nuclear fuel are present all over the world. Also, uranium can be extracted from sea water, but it’s a complicated and complex process.

Cost of Fuel: Fuel (uranium) itself isn’t too costly. However, if enriched uranium is used, then the cost of fuel increases considerably. A small amount of fuel is used, so transportation costs are less.

Initial Cost of Plant: Highest. A nuclear reactor is complex and requires the most skilled engineers.

Running Costs: Small amount of fuel used, so running cost is low.

Maintenance Costs: Very high. Skilled personnel are needed.

Transmission and Distribution Cost: Quite low. Such plants can be located near the load centers.

Start-up Power: 7% to 10% of unit capacity.

Starting time: Less than TPS. Can be started easily.

Standby Losses: Less.

Cleanliness: Radioactive waste is produced. Less clean than HPS.

Environmental Considerations: Disposal of radioactive wastes may affect the environment, especially if it is buried underground. Underwater contamination may occur.

Life Time: 40-60 years.

Author: Manoj Arora is an electrical engineering student and a writer from Gujarat, India. He writes poems and short stories whenever he's not immersed in a book.