Electricity Production

1st Law of Thermodynamics• An important Law of the Universe is the 1st Law of

Thermodynamics• Thermodynamics is a fancy way of saying ‘changing energy/heat’

• Thermo = heat/energy• Dynamic = changing

“Energy cannot be created or destroyed, only changed from one form into another”

1st Law of Thermodynamics• Think back to making static electricity• You changed movement (called kinetic energy) into electricity

(electrical energy)

• The movement in your body (kinetic energy) is made your muscles that use chemical energy that you get from your food

• In circuits, the electricity didn’t just ‘appear’ out of the battery• Batteries convert chemical energy (using chemical properties of

the chemicals inside) into electrical energy

1st Law of Thermodynamics• This means that we can never really ‘create’ electricity• Instead we must convert another type of energy into electricity

• Currently we use generators to make the majority of our electricity

Generators• Generators make AC electricity

• Generators supply almost all of the power that comes into your homes

• Converts Mechanical Energy (motion) into Electricity

Generators• Generators have 2 basic parts

1) Magnets

2) Coils of copper wire

Magnets• Just like charged objects create electric fields, magnets also

create fields

• These are called Magnetic Fields• They are a lot like electric fields

• If a magnet moves, the magnetic field moves with it

Generators• In a generator, the magnet rotates

• Since electrons have a charge, they can be moved by magnets or electricity• Charge = can be moved by magnets

or electricity

• If the magnet moves, it’s magnetic field moves• This pushes the electrons creating

current and voltage

• Generators may also keep a magnet still and rotate a coil of wire. This has the same result.

Generators• Generators are what create most of electricity that we use on

a daily basis. It is what is transported through power lines to your homes

• Generators convert Mechanical Energy into Electricity

• If we have a way of turning a generator, we can create electricity

Types of Electrical Generation

• There are many ways to create electricity• We are going to look at the following ways to create

electricity1. Hydroelectricity2. Fossil Fuels (Coal, Oil, Gas/Diesel)3. Biomass4. Nuclear Power5. Wind Power6. Tidal Power7. Solar Power*

*Doesn’t use a generatorNot every way of making electricity is going to be looked at in this class

Hydroelectricity• Hydroelectricity uses falling

water to create electricity• A river is dammed off to create a

large reservoir of water (a lake)• The dam allows some water to

flow through a channel• The water falls and spins a

generator as it falls• This create electricity

• This is a renewable source of electricity

Pros and Cons of Hydroelectricity

• Expensive to start but cheap after the dam is built• Renewable energy• Steady, reliable source of electricity• No release of greenhouse gases or pollution• Can be harmful to aquatic life (fish, water birds, etc.) that rely

on a river• Causes the flooding of a large area to create the reservoir• This may cause people to have to relocated where they live

• Creation of reservoir may force some animals to relocate• Lake can be used for recreation (boating, fishing, water skiing,

etc.)

Fossil Fuels• Fossil Fuels can be burned to create Heat

Energy• Coal, Oil, and Gas are Fossil Fuels• They are non-renewable (cannot be

remade easily)• Coal, oil, or gas are burned to create heat• This heat boils water into steam• The steam is forced through a pipe at high

pressure• The steam then turns a generator, creating

electricity• The steam is recycled back into liquid water

and reheated

Fossil Fuels

Fossil Fuel Cons• Burning fossil fuels releases

many chemicals into the atmosphere

• Among these a lot of Carbon Dioxide and other Greenhouse Gases

• These are believed to be the cause of Global Climate Change• The gradual warming of the

Earth that is changing weather patterns all over

Fossil Fuel Pros• Fossil Fuels are relatively cheap, readily available, proven to

work, and they create lots of heat.

• This means we can have lots of electricity when we need it.• We can have relatively cheap electricity

• Fossil fuels also make lots of jobs, as we need people to mine the coal/oil/gas/etc., people to process them, and people to run the power plants.

Biomass• Biomass is flammable material

that is alive, was once alive, or came from living things.• Bio means life

• Biomass is things like leftover plant material, manure, garbage, and other materials that come from living things that can be burned• Biomass is typically burned to

heat water• The water turns to steam• The steam turns a generator

Biomass Pros and Cons

• Biomass uses material that is typically thrown away or unused.• Biomass is burned, releasing some greenhouse gases• This means it contributes to global climate change• It doesn’t release as many greenhouse gases as fossil fuels• It does release less toxins than fossil fuels

• Biomass is renewable• Can be expensive• Less reliable (sometimes cannot get as much biomass to burn)

Nuclear Power

• In nuclear power, atoms are split to make LOTS of heat

• This heat boils water into steam• The steam turns a generator• The generator makes electricity

Nuclear Power• Nuclear power uses Fission (splitting)• Fission is when the nucleus of one atom is split into 2 or more

atoms, releasing heat in the process• This is the same process used in nuclear bombs, but is much

more controlled and is fairly safe if done properly

Nuclear Fission

1. A neutron is shot at the nucleus of an atom (usually Uranium)

2. The Uranium atom splits into other atoms and releases more neutrons and heat.

3. The other neutrons hit other nuclei, breaking them apart and releasing more heat and more neutrons.

4. The neutrons then continue breaking atoms in a chain reaction.

Nuclear Fission

Nuclear Power

Nuclear PowerPros and Cons

• Nuclear Power makes ENORMOUS amounts of electricity

• The atoms made by splitting uranium are very radioactive, very dangerous, and last for millions of years.• It does not make very much of them, however.• These radioactive atoms are very hard to store

• Does not make ANY greenhouse gases• The process can sometimes get uncontrollably

hot if not down carefully.• This causes parts of the power plant to start

melting• This is called a Meltdown

Wind Power• Wind turbines look like giant fans• When wind blows, the blades are turned.• These blades are connected to a generator.• When the blades spin, so does the generator

Wind Pros and Cons

• Wind creates no greenhouse gases, no waste, and no global climate change• Wind is expensive to start but cheap after being

built• A renewable source of energy• Less jobs are required to maintain• Vibrations from the turbines have been linked to

health problems such as heart beat changes, headaches, dizziness, nausea, memory problems, ringing in ears, and sleep problems for those who live nearby.

Tidal Power• Everyday, the ocean level rises

and falls due to the Moon’s pull of gravity. • This is called the Tide

• As the tide comes in (the water rises), the water rushes past a set of blades and rotates them.• This turns a generator and

makes electricity• As the tide goes out (water goes

down, the water turns the blades and rotates a generator.

Tidal Power Pros and Cons

• Renewable, predictable source of energy• Not continuous, no energy when no tide• No greenhouse gases or pollution• Very harmful to sea life and birds that rely

on areas to live• Very expensive to start• Often far away from places that need

electricity so expensive to set up cables• Can be plugged by waste, pollution, or mud

Solar Power• Solar Power DOES NOT use

generators• Instead it uses Solar Panels that

make DC electricity• Solar panels are made of silicon• When light hits thin layers of

silicon, it can make the silicon release electrons.

• This silicon is hooked to a circuit so the electrons can flow and come back to the silicon, where they are absorbed back into the material

Solar Panels

Solar Power Pros and Cons

• Solar power is renewable• No greenhouse gas emissions• Pollution made is creating solar panels• Easy to get power in remote locations• Very expensive to start (can be up to

$1000/solar panel)• No energy when no sunlight

Making Electricity

• There is no ‘perfect’ way to make electricity• Every way of producing electricity causes

some problems• These problems all come from the 1st Law

of Thermodynamics•We must convert another type of energy

into electricity• The only way to reduce the problems is to

USE LESS ELECTRICITY

Reducing You Electrical Consumption

• Unplug electronics you aren’t using• Leaving things plugged in still uses some electricity

• Turn off things your aren’t using• Turn off lights if you’re not in the room• Your cable box, computer, or gaming system use more electricity

than most TVs. Turn them off when you’re not using them. • Try using less heat in the winter/air conditioning in the

summer• Hang clothes to dry instead of using the dryer• Buy EnergyStar appliances• Buy LED or CFL light bulbs instead of incandescent