1. What is the difference between renewable energy and alternative energy?

2. What does the phrase “energy conservation” mean to you?

3. What are the benefits of conservation?

4. What disadvantages to energy conservation can you think of?

Objectives:1.Describe three alternative energy technologies.2.Explain the difference between energy efficiency and energy conservation.3.Describe two forms of energy efficient transportation.

Def: Energy sources that are still in development

Must be shown to be cost effect to become a viable option for the future

What alternative energy sources can you think of?

Some alternative energy sources: Tidal power Ocean thermal energy conversion Hydrogen

Tides (high and low) occur twice a day.

Used 1000 years ago to power mills in France and Britain.

Used today in France, Russia, and Canada to generate electricity.

Disadvantages: Expensive to build and maintain Few suitable locations

Def: using ocean temperature differences to produce electricity

Experimental power station off Hawaii

Disadvantages: Expensive and inefficient Environmental effects of returning

large amounts of cold water to the surface?

http://www.offinf.com/otec_movie.htm

Most abundant element in the universe

Does not contain carbon, so no fossil fuel-type pollutants

When burned, it produces water vapor and small amounts of nitrogen oxides.

Disadvantage: takes a lot of energy to produce

Def: produces electricity chemically, like a battery, by combining hydrogen fuel and oxygen

The only by-product (or waste) is water.

Hydrogen can be obtained from alcohol, natural gas, or gasoline.

Electricity from bacteria Read “Science & Technology”,

p.479. Water pumps and seesaws in

Columbia Human-powered washing machines

Def: the percentage of energy put into a system that does useful work

Energy efficiency (in %) = energy in/energy out x 100

Overall, more than 40% of all energy used in the U.S. is wasted.

Some solutions are simple: better insulation, fluorescent light bulbs. Others require sacrifice or new technology.

Hybrid cars Use a small, efficient gasoline engine

most of the time Also use an electric motor when extra

power is needed Convert some of the energy of braking

into electricity and store it in the battery

Gasoline engine shuts off when car is stopped at a red light

Def: saving energy Using more efficient devices Wasting less energy

Some cities offer incentives

How can we conserve energy around the home?

In daily life?

Wash clothes in cold water