Hydroelectric Power
Hydroelectric power is power that comes from falling, streaming or flowing water. Dams are built on rivers to control the water. The water pushes the turbine which makes the generator work, and then electrical charges come out of the generator into the powerhouse. From there, the electricity enters the power lines which give light to cities, homes and other buildings. Once the water rotates the turbines it returns to the rivers.
Pros
• Water is renewable, you won`t run out of water. Rain, snow and ice are all factors in keeping rivers flowing.
• Hydroelectric Power is a clean energy source because there are no toxins or greenhouse gasses
• It is reliable. As long as there is water and the turbines and generators work, there will always be power
• There is a low operating cost. Once the dam is built and the turbines and generators are up and running, there is very little cost and maintenance
• There are some recreational perks. The lakes that are formed behind the dams are great for fishing, swimming and other recreational activities
• There is no fuel or nuclear energy, so it is safe for all
Cons
• There is potential for environmental damage such as:
– altering the normal flow of the river,
– blocking of migratory fish passage,
– changing the water level of the river could affect the fish
– sudden occurrence of floods
• They are expensive to build: like any building, the cost of something this large would be costly
• In the event of a drought, electrical power would be affected
• Concern over dams breaking may affect the lower lying local communities. The communities may be displaced for fear of flooding.
• Building a dam could affect the water supply elsewhere since rivers usually flow into oceans.
Thermal Power Plants
Thermal Power Plants aim to convert heated water into steam by burning fossil fuels such as coal, oil and diesel. The heat energy drives turbines and from there, the electricity enters the generator which flows into the powerhouse and further into the power lines into homes. Thermal power coming from fossil fuels is the most common energy form on earth.
Pros
• Fossil fuels are the easiest sources of energy and can be found and accessed throughout the world. Because of their abundance, they are also cheap.
• Fossil fuels can be easily transported from one place to another. Coal, oil and gas can easily be moved to different locations
• Fossil fuel energy industries help in generating loads of employment opportunities for all sections of society.
Cons
• Pollution. Chemicals and greenhouse gases are emitted during the production of electricity with fossil fuels.
• Natural ecosystems and landscapes are destroyed in building power plants
• Expensive to build and maintain.
• A concern that these non-renewable resources such as coal and oil will become scarce or run out.
• Danger to areas surrounding the power plants and people working at the plants. People working at these plants need to be extra cautious and have to be provided with adequate safety measures. Blasts, oil leaks, fire breakouts and the release of toxic gases can be fatal for those working at these plants and can also, in some cases, retard growth and life.
• Waste disposal. Some of the waste elements are dumped into the ocean or on land and can be extremely toxic for marine and other life, hindering the natural flow of ecosystems.
1. http://www.conserve-energy-future.com/pros-and-cons-of-hydroelectric-power.php
2. http://water.usgs.gov/edu/hyhowworks.html
3. http://lifestyle.iloveindia.com/lounge/pros-and-cons-of-thermal-power-13991.html