Question

Hydroelectric power plants are more ecofriendly than thermal power plants. Justify this statement.

Answer 1

Hint: Hydroelectric power plants do not produce any toxic gases or any other kind of waste. On the other hand, Thermal power plants convert heat energy to electricity. This heat is generated by burning fossil fuels and produces polluting gases as a side product.

Complete step-by-step answer:
Hydroelectricity means electricity generated from water. Usually to generate electricity, dams are constructed on rivers to store river water in a reservoir. Water released from the reservoir is then used to turn turbines, which activates a generator to produce electricity. Thus, we can say hydroelectric power plants use mechanical potential energy of water, convert it into kinetic energy and use this kinetic energy to spin the turbine to generate electricity.
The word ‘thermal’ is related to heat. A thermal power plant is the power station where heat is converted to electric power. Usually, in a thermal power station, water is heated to convert it into steam, which in turn drives a turbine. The steam is then condensed back in a condenser and recycled. Different types of thermal power plants use different kinds of heat sources to generate heat such as fossil fuel, nuclear energy, biofuels etc. In this process, a lot of harmful gases and ash are released which are a side product of burning the fossil fuels. Thermal power plants also cause thermal pollution.
Hence, we can conclude that hydroelectric power plants are more ecofriendly than thermal power plants.

Note: Although, hydroelectric power plants are more ecofriendly than thermal power plants but they often cause loss of biodiversity. Construction of dams requires more land especially in flat areas. If, due to any reason, these dams burst, they cause a large destruction causing flood which destroys wildlife, forests, agricultural land etc.