1. Renewable and Inexhaustible Energy Sources
Chapter 5
Renewable and Inexhaustible Energy Sources

2. Objectives
Identify the basic sources of renewable energy and inexhaustible energy.
Explain the advantages, & disadvantages of various conventional and alternative energy resources.

3. Renewable Energy Sources
The basic renewable energy sources include animals, food, wood, and alcohol.
Animals served as a major source of mechanical power until the development of mechanical machines. Animals are also used for food.
Food is a renewable source of energy for humans and automobiles. Gasohol is made from grains to fuel automobiles.
Wood can be an inexpensive renewable energy source.
Alcohol is made from different crops such as corn, sugar beets, and sugar cane. In Brazil automobiles operate on 100% alcohol fuel.
Methanol can be made from coal, wood, plants, and manure.
Bioconversion produces energy from waste products. Trees, plants, grains, algae, manure, garbage, sewage, and paper can be used. A methane digester converts shredded organic material into methane gas (fig 5-7, page 103).

4. Inexhaustible Energy Sources
The most frequently used are hydroelectricity, geothermal, & wind. Since forces beyond our control renew these sources, these sources are considered to be inexhaustible.
Hydroelectric: A turbine spins a generator as the water behind a dam comes rushing through a tunnel (fig 5-12, page 107).
Geothermal: Development is limited to locations where the heated steam is close enough to the earth’s surface in order to make it economically recoverable. Geothermal heat pumps are based on the fact that underground temperature remains at approximately 550F. They can be reversed to provide cooling in the summer months.
Wind: generally wind speeds in excess of 11 mph are necessary to drive a wind turbine. One study suggests that 16,000 square miles of land is required to produce 20% of electrical demand of the United States. About 95% can be dual use for farming or ranching.

5. Summary
The basic renewable energy sources include animals, food, wood, and alcohol.
Alcohol is made from different crops such as corn, sugar beets, and sugar cane. In Brazil automobiles operate on 100% alcohol fuel.
Methanol can be made from coal, wood, plants, and manure.
The most frequently used inexhaustible energy sources are hydroelectricity, geothermal, & wind. Since forces beyond our control renew these sources, these sources are considered to be inexhaustible.
Geothermal: Development is limited to locations where the heated steam is close enough to the earth’s surface in order to make it economically recoverable. Geothermal heat pumps are based on the fact that underground temperature remains at approximately 550F. They can be reversed to provide cooling in the summer months.
Wind: generally wind speeds in excess of 11 mph are necessary to drive a wind turbine.

6. Home Work 1. What are the basic renewable energy sources?
2. What are the most frequently used inexhaustible sources of energy?