1. 12.3 Meeting the Demand for Electricity (Pages 501-505) Homework: Page 505 # 1, 3, 5, 6, 7 Key Concepts (Page 505)

2. Base load is the continuous minimum demand for electrical power. It is met by using large generators that run on the least expensive fuels. Intermediate load and peak load are met by using smaller generators that can be turned on or off quickly.

3. Ontario obtains most of its electrical energy from nuclear, hydroelectric, and fossil fuel-burning stations. The rate that is charged for electricity changes when the cost of the fuel that is used to generate that electricity changes.

4. 1. Compare a renewable energy source with a nonrenewable energy source. A renewable energy source can be replaced in a relatively short period of time while a nonrenewable energy source cannot be replaced as quickly as it is used.

5. Advantages of Hydroelectric Power No emissions No fuel cost Low operating costs Process is 90% efficient Can be brought on line quickly A renewable energy source that can be replaced in a relatively short time

6. Disadvantages of Hydroelectric Power The flooding of large areas when the reservoir behind a dam is created. Major hydroelectric projects are very expensive to construct. Flooded vegetation decomposes and produces methane, a potent greenhouse gas. Natural spawning routes for fish are harmed. Mercury released from submerged soil and vegetation can end up in fish.

11. Nuclear Power About 51% of Ontario’s capacity to generate electricity comes from three nuclear power plants. The heat from nuclear reactions produces steam that spins turbines that in turn spin electrical generators.

13. Coal Power Plant Advantages: Canada has large known reserves of coal. The cost of generating electricity with coal is very low. Disadvantages: The energy conversion is very inefficient. Gases that contribute to acid rain and global warming are produced. Coal is non-renewable, meaning supplies will eventually run out.