UNDERSTANDING ENERGY

“ENERGY AND THE ENVIRONMENT” 1

ST

MP PROJECT

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WHAT YOU NEED TO KNOW

Questions

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Answers

1. Why is it important to understand energy resources and how they impact the environment?

• Among many other reasons, fossil fuels that are used in every aspect of our lives are being depleted at an ever-increasing rate, leaving us with tough choices about our consumption of energy. 2. Where does our energy • come from and what are all the costs of using it? Today, most of the energy for our activities comes from the burning of fossil fuels. Using this energy affects our economy, environment, and health. 3. How can we reduce our consumption of energy? • We can save energy by investing in energy saving technology and modifying our usage behaviors and habits. • 4. And, what alternative sources of energy can help meet our energy needs? Renewable sources of energy such as solar energy, wind, geothermal energy, and biomass will help address future energy needs, and help to protect our natural resources.

Understanding Energy

Energy lights our homes, fuels our transportation systems, and much more, but affordable energy is in limited supply. In this project, you will look at the global impact of these limits and see how being smart about using energy will become more important in your daily lives.

Where does our energy come from? The U.S. Department of Energy publishes data on the many energy sources we use in this country. The majority of the energy we use comes from the fossil fuels: 38% from oil, 22% from coal, and 23% from natural gas. The remaining 17% is supplied about equally by nuclear and renewable energy sources. About 29% of our energy supply is currently imported — almost all of it as crude oil.

Energy consumption has changed drastically over the past four hundred years (see chart graphic above). Most striking is the overall rise in energy use, particularly fossil fuels, during the 20th century. Annual consumption of oil and natural gas eclipsed coal in 1947, and quadrupled in a single generation.

How Is Energy Used?

The Energy Information Administration (EIA) reports that more than half of our energy (52%) is used by business and industry. The rest is used for transportation (27%) and to keep us comfortable in our homes (21%).

The above diagram provides us with an easy way to see not only where our energy is used but also where we get our energy.

Nationally, our energy costs are currently around 570 billion dollars each year. This EIA graph is helpful in showing how energy consumption patterns have changed in the last fifty years.

Renewable Energy Sources

Renewable energy sources are those provided directly or indirectly by the either the Sun or the Earth's processes. They include: solar energy, wind energy, bioenergy, geothermal energy, hydropower and ocean energy. They are constantly replenished and will always be available for our use.

Sunlight, or solar energy, can be used directly for heating and lighting homes, captured in solar cells to generate electricity, and used to heat residential hot water. Solar energy is also the cause of wind, which can be harnessed through windmills to pump water, grind grain, or produce electricity. The energy provided by the Sun also makes plants grow, and the organic matter that makes up those plants (biomass) can be used to produce electricity directly, or become stored in fuel or chemicals.

Geothermal energy uses the Earth's internal heat to make steam, which can produce electric power or heat buildings. Rivers and streams were once used as a direct energy source for industry and some have been blocked with large dams to provide falling water to produce electricity.

The energy of the ocean's tides is another renewable source. In the future we might even use waves or the differences in the ocean temperature to extract energy for our use or decompose water to produce hydrogen as a clean burning fuel.

HOW DO YOU KNOW ABOUT ENERGY?....

WANT TO TRY A GAME TO SEE???

"Energy cannot be created and cannot be destroyed."

Does this sound familiar? It is the

Law of Conservation of Energy

. So, if energy cannot be created, everything that uses energy has to get it from somewhere. For instance, when you push a stalled car, the car gets energy from your muscles, which get energy from your food, which gets energy from... where?

In the

Tracing the Path

game, draw arrows connecting the sources of energy to the receivers of energy. First click on the

source

, then click on the

receiver

. For example, click on the wind, then click on the windmill. If you are correct, a connecting arrow will appear. If you are wrong, the computer will only beep. To get a hint or learn more about where a particular receiver gets its energy from, click on a button.

Go on to Tracing the Path!

Here are some general hints:

•Some sources of energy have more than one receiver. •Some receivers of energy have more than one source. •One source-receiver pair (and only one pair) can send energy in either direction!