Renewable Energy - Pros and Cons
During the 1960's and 1970's people began to fear that the main source of energy, the fossil fuels, would run out. Fossil fuels are finite or non-renewable and once they are used they cannot be replaced. In recent years, people realised that there was enough fossil fuels to last for several hundred years. A greater problem was the damage that was being done to our atmosphere. This has led to interest in renewable energy sources that do very little damage to the environment. These are some of the main renewable energy sources:
Hydroelectric Power (HEP)
Dams are built to control fast flowing rivers so that the water can be used to turn turbines to generate electricity. At times when the energy is not needed, the water can be pumped back up to the storage reservoir.
|Adv. of Hydroelectricity||Disadvantages of Hydroelectricity|
- Abundant, clean, and safe
- Can have a significant environmental impact
- Easily stored in reservoirs
- People can lose their homes
- Offers recreational benefits like boating, fishing, etc
- Can be used only where there is a water supply
Barrages can be built across estuaries to use tidal flows to generate electricity.
|Advantages of Tidal power||Disadvantages of Tidal power|
- Abundant, clean, and safe
- Not commercially viable at present
- Shipping could be disrupt
The sun's warmth can be used to heat water and buildings. Solar cells can convert sunlight into electricity.
|Advantages of Solar power||Disadvantages of Solar power|
- Reliability depends on sunlight
- No water or air pollution
- Not really cost effective at present
- Storage and back-up are necessary
Biomass is the oldest of the renewable energy sources and, in Ireland, its main use is as wood fuel. Another source of Biomass energy comes from the production of biogas. Municipal solid waste, agricultural waste and sewage sludge break down to produce Methane. This methane can be collected in tanks and burned to produce heat.
|Advantages of Biomass||Disadvantages of Biomass|
- Burning biomass can result in air pollution
- Can be used to burn waste products
- May not be cost effective
Water is pumped through hot rocks under the ground. The hot water can be used to heat buildings and any steam produced can be used to generate electricity. Low temperature geothermal energy, found in Ireland, can be tapped using heat pump technology.
|Advantages of Geothermal Energy||Disadvantages of Geothermal energy|
- An unlimited supply of energy
- Best supplies limited to certain areas of the world
- Produces no air or water pollution
- Start-up costs are expensive
- Corrosion of pipes can be a problem
Wind Tall wind turbines on wind farms can use the power of the wind to generate electricity. Eleven wind farms are now operational in Ireland. These have a combined capacity of 68 MW - enough electricity for over 44,000 homes.
|Advantages of Wind energy||Disadvantages of Wind energy|
- Produces no water or air pollution
- Farmers can receive an income from any electricity generated and the land can have other uses
- The wind farms can have a significant visual impact
- Wind farms are relatively cheap to build
- Wind farms need a lot of land
Questions on Renewable Energy
1 The renewable energy sources can vary from area to area. This depends on the type of climate found in the area or the underlying geology or the shape of the land. What types of energy could be used in the following areas:
(a) A wet mountainous region with few people.
(b) A flat windswept region.
(c) A dry, hot region without much vegetation.
(d) A flat agricultural region beside a major city.
2 Study the tables below. What is the most important renewable energy source in Ireland? Why do you think that this is source is so important. Be sure to answer fully using information from the tables.
3 What types of renewable energy could be used in the following countries:
(a) Mali in West Africa
(b) Iceland or Japan (Both are on Plate margins)
(c) The Orkney Islands, north of Scotland
4 Look at the advantages and disadvantages of the renewable energy sources and try to decide which have the most benefits and least problems. Why do you think these sources of energy are not used much more than they are?
5 Using the Internet, your textbooks, newspapers and any other sources of information you may have, make a study of renewable energy sources. Are there any in your local area? Many areas have old water wheels or even windmills. What were these used for? Are there any plans to develop renewable energy sources in your area?