CH5L1: Energy Resources

Chapter 5 Lesson 1

Energy Resources

Sources of Energy

• Nonrenewable resources are resources that are used faster than they can be replaced by natural processes - fossil fuels, such as coal, oil and uranium.

• Renewable resources are resources that can be replaced by natural processes in a relatively short amount of time - solar energy, wind energy etc.

Nonrenewable Energy Resources

• Fossil Fuels - coal, oil, and natural gas. They form over millions of years and the type of fossil fuel formed depends upon: type of organic matter, temperature and pressure, and the length of time it was buried.

Coal

• The first step of coal formation occurred when plants died. A few hundred million years ago.

• Bacteria, extreme temperatures, and pressure acted on the remains

• Eventually a brownish material, peat, formed.

• Peat can be used as fuel, however it produces a lot of smoke when burned.

• Over time, peat hardens into coal.

Oil and Natural Gas

• Oil and natural gas form from different types of organisms than coal. They are formed from marine plankton that fell to the ocean floor.

• Bacteria decomposed the orgainc matter, and pressure and extreme temperatures acted on the sediment.

• During this process, thick, liquid oil formed. With enouth temperature and pressure, natural gas formed.

Oil and Natural Gas

• Oil and natural gas are less dense than the rock and sediment that surrounds it.

• So oil and natural gas rise to the surface, passing through small pores in rocks.

• Eventually it will reach a layer that it cannot pass through. They will form deposits here, with the less dense gas settling on top of the oil.

Multiple Select

What factors determine which types of fossil fuels form?

• type of organic matter

• temperature and pressure

• length of time buried

• the weather

Advantages of Fossil Fuels

• The process of turning fossil fuels' chemical energy into electric energy is quite straight-forward and easy.

• Fossil Fuels are relatively inexpensive and easy to transport.

Disadvantages of Fossil Fuels

• Limited supply: Fossil fuels are nonrenewable, we'll run out eventually. Scientists predict that known oil reserves will last another 50 years at most.

• Habitat Disruption: Obtaining fossil fuels disturbs then environment. Mines disturb forest habitats, large batches of oil are routinely spilled into the ocean by large companies.

Disadvantages of Fossil Fuels

• Pollution: run off from coal mines can pollute soil and water.

• Burning fossil fuels releases chemicals into the atmosphere.

• Chemicals can react with water and cause acid rain.

Nuclear Energy

• Atoms are too small to see with just our eyes. However, they can release huge amounts of energy. Energy released from atomic reactions, is called nuclear energy.

Nuclear Fission

• Uranium atoms are placed into fuel rods. Neutrons are aimed at the rods and hit the Uranium atoms.

• Each atom splits and releases 2-3 other neutrons and thermal energy. The released atoms carry on a chain reaction.

• Countless split atoms release large amounts of thermal energy, this energy heats the water and changes it to steam.

• The steam turns a turbine connected to a generator, this produces electricity.

Advantages and Disadvantages of Nuclear Energy

• Advantages: only requires small amounts of uranium to produce large amount of energy. A well-run nuclear power plant won't pollute the air, soil or water.

• Disadvantages: Uranium isn't renewable. The chain reaction can get out of hand if not closely monitored. Radioactive substances can contaminate the environment. Radioactive waste materials remain dangerous for thousands of years.

Managing Nonrenewable Energy Resources

• Mined land must be reclaimed. Reclamation is a process in which mined land is recovered with soil and replanted with vegetation.

• The Clean Air Act in the US limits the amount off pollutants companies can release into the air.

• Stop vampire energy, the energy ised by appliances plugged in 24 hours a day, like TV's, washing machines, microwaves etc. These appliances consume about 5% of energy used each year.