EnergyWhat is it?

By Moira Whitehouse PhD

Remember, energy is the ability to move matter or change matter.

Imagine what the world would be like if nothing moved or changed.

What are some of the different forms of energy?

List as many as you can remember from our previous study of energy.

mechanical

light

electrical

sound

heat

chemical

Fossil fuels are used to produce two kinds of energy that are very important to us.

Let’s first look at mechanical energy—the energy of moving things. You and others depend on many things that move.

What are some of these things?

Yes, our cars,

trucks,

trains,

buses,

tractors

But in order to move, all these vehicles must have a fuel.

What fuels do these vehicles burn?

The fuel for each of these vehicles usually comes from crude oil, a fossil fuel.

Remember all the fuels that come from crude oil?Gasoline, diesel fuel and jet fuel are the fuels for transporation.

Another form of energy we depend upon is electricity.

But electricity has to be generated. Just how is electricity generated?.

To generate electricity you have to turn a magnet inside a coil of wire or turn a coil of wire inside a magnetic field.

Open this website to see how this is done.

http://new.wvic.com/index.php?option=com_content&task=view&id=9&Itemid=46

And what force is used to turn the wire or magnet?Often it is steam. Coal and natural gas (two more fossil fuels) are burned heating water to make steam.

The turbine turns the coil of wire inside the magnet.

Coal is burned.

The burning coal heats the water.

The water changes into steam.

The steam turns the turbine.

Electricity isgenerated.

The electricity travels from the power plant by wires to your house.

But there are many problems with burning the three fossil fuels.

What are some of these problems?

1. coal2. natural gas3. crude oil --gasoline and diesel fuel

• They are limited and very expensive. -Crude oil is becoming hard to find and even more expensive to obtain.• Burning these fuels puts:

• Accidental spills, as in the recent Gulf Oil spill, pollute our

water.

-pollutants into the air which are harmful to our health and

-carbon dioxide into the air which leads to global warming.

So what are we to do?

Man can use other (alternative) forms of energy to move our vehicles and generate electricity .

What are some of these alternative forms of energy?

These are alternative forms of energy

First let’s look at biomass.

Biomass is organic material made from plants. Biomass contains stored energy from the sun.

Some examples of biomass fuels are wood, corn, sugar cane and some types of garbage.

But where do these plant materials get their energy?

During photosynthesis, plants change the sun’s radiant energy into chemical energy in the form of a sugar called glucose.

So the energy from the sun is actually stored in the structure of the plant.

When plant material is burned, the stored chemical energy is released as heat. If you have a fireplace, the wood you burn in it is a biomass fuel.

Wood waste and certain garbage (forms of biomass) can be burned to produce steam for making electricity and also to provide heat for homes and industries.

Sugar cane and corn can be used to produce ethanol, a liquid fuel, that can be added to gasoline for vehicles.

Biodiesel, another transportation fuel, can be produced from left-over food products like vegetable oils and animal fats.

Alternative forms of energy

Then there is hydropower.

Dams are used to channel a river’s water flow through hydropowergenerators producingelectricity.

The flow of water powers the turbine that turns the magnet (or the coil of wire) inside the generator producing electricity.

Alternative forms of energy

Another is geothermal.

Geothermal energy is created by heat from inside the Earth.

Heated by the rock, it turns into steam which can be used to heat buildings or to generate electricity.

Water is injected under ground.

Alternative forms of energy

Then there is the wind.

Remember wind is caused by unequal heating of air.

Wind is used to turn the turbine inside an electrical generator.

Alternative forms of energy

Another is the energy of the Sun.

Solar energy can be converted to electricity in two ways:

First, solar cells change the energy from the Sun (solar energy) directly into electrical energy.

It would take many many solar cells to provide for all of a city’s electrical needs.

Concentrating Solar Power Plants to generate electricity. Mirrors reflect and focus the sun’s light on a containerof fluid. Thehot fluid changes water into steam which is used to power a generator.

The second way the Sun can be used to produce electricity is by using:

fluidmirrors

These are some of the alternative forms of energy

In summaryCan you think of some advantages of these alternative forms of energy?

Do they have any disadvantages?

(http://www.need.org/)

Below is a website that has good reading material that you can print (in black and white) alternative energy sources such as wind, solar, biomass and geothermal.

Under the tab student choose Energy Infobooks. Both the Complete Primary and Elementary Energy Infobooks are excellent.So are the individual printouts on each energy source such as coal, petroleum, natural gas, wind, solar, etc.