How People Use Energy

UNIT F CHAPTER 4

Ch 4 Lesson 1 Fossil Fuel Use

Fossil fuels are fuels that formed from the remains of once-living organisms.

They are:1. Coal2. Natural Gas3. Petroleum

Solar energy is stored as chemical energy, and it exists in all living organisms. It is mostly stored in chemical bonds.

Using Fossil Fuels

Fossil fuels are the main source of energy for nations like the U.S.

Fossil fuels release large amount of thermal energy when they’re burned.

Natural gas, coal, or oil heat your house on cold days, and allow heat for cooking food.

Petroleum is the main source of energy for transportation.

Cars, trucks, buses, trains and planes all use engines that run on petroleum such as; gasoline and diesel fuel .

Alternatives to Fossil Fuels

Fossil fuels are nonrenewable resources.

Nonrenewable resources such as fossil fuels take million of years to form, however, they are used quickly.

Scientists don’t know how limited the supply of fossil fuels are, so there are good reasons to use other sources of energy.

What can we do?

Harming the Environment

Burning fossil fuels releases large amounts of carbon dioxide in the air.

This is a major cause of global warming. These gases become trapped in the Earth’s atmosphere and cause environmental changes.

ALTERNATEFORMS OF ENERGY

Unit F Chapter 4

THINK-PAIR-SHARE

Review: What are the three major fossil fuels used to

produce energy?

1. COAL2. NATURAL GAS3. PETROLEUM

THINK-PAIR-SHARE

Question:Why do you think it is important to use other

energy sources beside fossil fuels?

Video Clip: Discovery Education: Pollution in the U.S.A.

Energy Used Around the World

Energy Use USAChinaRussiaJapanGermanyCanadaIndiaUKFranceItalyAll Others

K What you

already know

WWhat you want

to learn

L What you learned.

KWL Chart

Electricity and Moving Water

Hydroelectric Energy “hydro” means water

Electricity is generated from the force of falling water.

Water wheels have been used by people for thousands of years to produce energy.

During the Industrial Revolution the 1700 & 1800’swater wheels produced energy that turned machines in factories.

Hydroelectric Energy Now

1. Falling water spins a turbine.

A turbine is an improved water wheel.

2. Water strikes the blades of the turbine and makes it spin.

3. The rotating turbine than spins the shaft of an electric generator.

4. The electricity produced is than sent out over power lines.

Continued..

So where does energy in the water come from? Remember all Earth’s

energy comes originally from the sun

The energy that spins a hydroelectric generators comes from the potential energy of water under pressure.

Water near the surface exerts a force on the water below.

The great the depth of the water, the greater the potential energy. This is why people build

dams.

Tidal Energy

Tides rise and fall twice a day.

In some locations the change in water height is large.

When this happens, we can use the mechanical energy of moving water to produce electricity called; Tidal energy.

At high tide water is held back and than falls over the turbines during low tide.

Review Questions

1. What is hydroelectric energy?2. What is the name of a device that turn mechanical

energy into electricity?3. Why do tidal energy stations depend on large

differences in water height between high and low tide?4. Compare tidal energy with the hydroelectric energy

generated by a dam.5. Raising the level of water behind a dam improves the

efficiency of a hydroelectric plant by increasing..a) Water’s weightb) Water’s potential energyc) water’s temperatured) Water’s mass

Other Energy Sources

Biomass – organic matter, such as wood, that is living or was recently alive.

Advantages:Free energy sourceGarbage can be usedCan be made into modified gasoline

Disadvantages:Doesn’t release large amounts of energy

Nuclear Energy

Nuclear Energy – energy release when the nucleus of an atom is split apart.

Advantages:Releases large amounts of energy

Disadvantages:Fuel and the waster products of nuclear reactions can be dangerous to living organisms.

How it works.. Splitting nuclei

releases large amounts of energy to boil water. The resulting steam is directed through turbines and electric generators.

Berwick Power Plant

Wind Energy

Wind Energy – wind is used to turn turbines that produce electricity.

Advantages:FreeNon-pollutingInexhaustible

Disadvantages: ExpensiveWind is inconsistent

Geothermal Energy

Geothermal Energy – heat from inside the Earth. The heat comes from underground water lies close to hot magma.

The water boils, steam forces its way to the surface. Then it is used to turn turbines of electric generators.

Advantages:Free source of energy

Disadvantages:Not available everywhere

Solar Energy

Solar Energy – the energy of sunlight.

Solar collectors absorb and focus the sun’s energy to heat water. Swimming pools are an example.

Solar energy can also use solar cells to convert energy right into electricity.

The sunlight frees electrons in flat panels.

Solar panels are used to power satellites and even calculators.

Advantages:FreeNon-polluting

Disadvantages:ExpensiveSunny days are necessary

Fusion Energy

Fusion Energy – release when nuclei of two small atoms are forced together.

Same process occurs in the sun. The heat you feel on a sunny day is from this source.

Advantages:Release large amounts of energy.

Disadvantages:Extremely high temperature needed to start fusion energy. No material is known that could withstand these temperatures.

Review

We will now view a video on energy sources and complete a worksheet.

After the entire class views the video, you will work in groups of two to complete a worksheet. You will use the net books to go back and review the video to help answer the questions.

Review Different Forms of Energy

Resources

VideoEarth Science: The Basics: Natural Resources

and the Environment. Discovery Education.(2005). Retrieved December 3, 2009, fromDiscovery Education: http://streaming.discoveryeducation