Unidad 3 ESO Energia

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Unit 5. Energy

Unit 5. Energy 5.1 Energy 1.1Units 1.2 Forms and Sources 5.2 Electric energy 2.1 Generation 2.2 Main Power Stations 2.3 Distribution 5.3 Consume

5.1.1 Energy. Units

Energy is the capacity of an object to do a work.

And work is the force applied along a distance

5.1.1 Energy. Units In physics we define mechanical work as the amount of energy transferred by a force acting through a distance

W= F•d d= distance between A and B F= Force applied to move the object

F d

5.1.1 Energy. Units

Therefore, in this example, the energy that black cartoon has, the express the work that can apply to this box,

5.1.1 Energy. Units

Units There are several units of energy that are used in special areas, the most popular are the j, cal and kwh.

Joule calorie kwh

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5.1.1 Energy. Units

Joule (J) is the International System’s unit for work, and is usually expressed in Kj.

1kj is the energy need to raise 100kg 1 meter high

1 meter

5.1.1 Energy. Units

Calorie (cal) This unit is usually used to express energy that involves calorific transference. When energy is used in the alimentary industry, it’s usually express in Kcal. In the USA, they write Cal instead of Kcal…

In order to heat 1 L of water from 20 to 21 ºC we need 1kcal

5.1.1 Energy. Units

A human being needs around 2000 kcal per day of energy to do all the work that it needs.

5.1.1 Energy. Units

When you drink a Coke you are absorbing 139 Kcal of energy that is stored in the 39gr of sugar dissolved in the liquid.

139 Kcal 420Kcal 840Kcal

Investigate the energy that these foods have per 100 gr:

Yogurt Big Mac

Bread Apple

Biscuits Orange Fanta

Cereals Oil

Chips Butter

Solution

5.1.1 1º Exercise 5.1.1 Energy. Units

KiloWatt/hour(kwh) It’s the unit used to measure the electric consumption of an electric installation.

When we use a hairdrier of 1000 W for 1h, we have consumed 1 kwh

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5.1.1 2º Exercise

Conversion units 1Kwh= 1000Wh 1 W= 1 j/s 1calorie= 4,18 joules

2º Exercise: • Calculate the energy of a Coke in joules. • Calculate the energy measured in kwh that we absorb in 2h when we drink 2 Cokes? • If we use a 100W lamp, and we use Cokes to provide energy, how many Cokes do we need per second?

Solution 5.1.2 Forms and Sources So Energy is the capacity of an object to

do a work, and it can be stored in different forms of enery:

Calorific energy

Light energy

Mechanical energy

Electrical energy

Electric energy

Chemical energy

Nuclear

energy

5.1.2 Forms and Sources The law of conservation of energy

expresses that can neither be created nor destroyed, it can only be transformed from one state to another

Calorific energy

Light energy

Mechanical energy

Electrical energy

Electric energy

Chemical energy

Nuclear energy

5.1.2 Forms and Sources

In order to obtain energy we have to use the different energy sources present in Earth: oil, coal, wind, uranium, etc.

5.1.2 Forms and Sources We can classify the energy sources

according to its: Origin: Renewable or Non Renewable Historical use: traditional or alternative Transformation: Primary or secondary

5.1.2 Forms and Sources

3º Exercise: a) Explain the difference between

the concepts of source and form of energy.

b) Define the six groups of energy sources, and give four examples of each.

solution

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5.1.2 Forms and Sources Origin: a) Renewable : These sources are Inexhaustible, therefore we can use them continuously. For example: Wind, Waves, etc…

5.1.2 Forms and Sources Origin: . a)

b) Non Renewable : These sources are exhaustible, therefore we consume the source when we use it. For example: oil, Uranium

5.1.2 Forms and Sources Historical use: a) Traditional: these sources have been

used for at least 30 years, and they provide more than the 90% global energy. They are:

Hydraulic, Coal, Oil, Gas, Uranium

5.1.2 Forms and Sources Historical use: a) Traditional

b) Alternative: these sources can provide energy but they can’t displace the alternative energy because they are cheaper or easier to obtain. For example

Solar Wind bio-mass Wave Geothermal

5.1.2 Forms and Sources Transformation: a) Primary: These sources are obtained

directly from the environment and they can be used directly without any transformation.

For example: Hydraulic, Coal, Oil, Gas, Solar Wind bio-mass Wave Geothermal

5.1.2 Forms and Sources Transformation: a) Primary: b) Secondary: These sources are obtained

after the transformation of a primary source. We use them because they are cleaner or easier to use

For example: Electricity, Oil derivatives (Gasoline, Diesel, etc), Town Gas

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5.1.2 exercise 5Forms and Sources 5º Exercise: Make a list of 20 objects

indicating the source of energy used and the energy obtained .

For example: TV-Electricity

Object Energy Source Energy obtained TV Electricity Light . . . . . . . . .

Sol Electricity production.

Why do we like Electricity so much?

5.2.1 Electric energy. Generation

Electricity is the principal source of energy in the developed homes and in industries because it’s the cleanest and most versatile energy.

5.2.1 Exercise. Electric energy. Production

1º Exercise: Compare the use of electricity at

home with the use of coal, oil, gas, solar, wind, geothermal, uranium.

2º Exercise: What do we mean when we say that

the electricity is clean? Solution

As we know, if we want to create an artificial electric current, we only need:

A closed circuit An artificial magnetic field A mechanical energy to move the circuit

inside the field.

5.2.1 Electric energy. Generation When we have all elements together, we

find that we create an alternate electric current due to the movement of the spiral.


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The only difference between power stations is how they get the energy to move the turbine that moves the circuit inside the generator

5.2.2 Electric energy. Power Stations

Generator turbine

One big group of use different sources to HEAT water and create steam to move the turbine


turbine

steam

Other small group use the primary source to move the turbine, using water or wind

5.2.1 Electric energy. Generation In conclusion we will always find these

elements in a Power Station:


Mechanical Energy

Generator Turbine

Electric generation

Electric Transformation

Electric Transport

Transformer

Primary Energy

Electric Transport

And this is the summary of the production in a block diagram


Mechanical Energy

Water or Air

Steam from a

combustion, nuclear

reaction, solar or geothermal

Electric generation

Electric Transformation

Turbine Generator Transformer

Primary Energy

POWER STATIONS

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Steam

Turbine

Generator

Transformer

Mechanical Energy

Electricity

Pylon

High Volt

All Power stations will have this elements, now we will see how they move the turbines

Water, Wind

5.2.2 Electric energy. Power Stations Steam Power Station Diagram 5.2.2 Electric energy. Power Stations

Steam

Boiler

Turbine

Generator

Transformer

Cooling

Mechanical Energy

Electricity

Cold Water

Heat

Pylon

High Volt

Steam

We use the energy source to create steam pressure to move the turbine

Turbine

Generator

Transformer

Mechanical Energy

Electricity

Pylon

High Volt

We use the primary Energy like wind or water pressure to move the turbine


Wind

Water Coal power Station


Steam pressure

Coal power Station Diagram 5.2.2 Electric energy. Power Stations

Steam

Mine Furnace

Boiler

Turbine

Generator

Transformer

Cooling

Mechanical Energy

Electricity

Cold Water

Heat

Pylons

High Volt

Steam

Coal

9º Exercise. Draw the diagram of all Power Stations

as we have seen in the Coal Station Diagram


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Coal power Station Advantages Inexpensive compared to other energy sources Coal is present in most of the countries, so they don’t have to buy it

abroad By-product of burning, ash, can be used for concrete and roadways Disadvantages Limited supply, non-renewable resource. 100 years The Carbon dioxide generated increase the effect of the global

warming. Generated smoke can cause health conditions such as emphysema Sulphur dioxide and nitrogen emissions can bind to water creating

acid rain Coal mining mars the landscape

5.2.2 Electric energy. Power Stations Nuclear power station


Diagram

Infografía

Nuclear power station Advantages Worldwide nuclear energy avoids on average the emission of more than two billion

metric tones of carbon dioxide per year, decreasing the effect of the global warming.

Although nuclear power reactors are expensive to build, they are relatively cheap to operate.

It is possible to generate a high amount of electrical energy in one single plant. Disadvantages The waste from nuclear energy is extremely dangerous and it has to be carefully

looked after for several thousand years . Despite a generally high security standard, accidents can still happen. Nuclear power plants as well as nuclear waste could be preferred targets for

terrorist attacks. Is a non renewable source. 50 years

5.2.2 Electric energy. Power Stations Hydro Power Station

5.2.2 Electric energy. Power Stations Diagram

Primary Energy


Hydro Power Station Advantages When the electricity is generated, no greenhouse gases are

made. Water is a renewable energy source and free. We create huge potable water deposits. Disadvantages The dam is expensive to build and the nearby area has to

be flooded In drought season we may not have enough water to turn

the turbines.

Solar Power Tower Plant 5.2.2 Electric energy. Power Stations

Diagram

Steam pressure

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Solar photovoltaic Plant 5.2.2 Electric energy. Power Stations

Diagram Solar Energy Advantages Inexhaustible fuel source No greenhouse gasses emited Versatile since it is used for powering items as diverse as solar cars and

satellites Disadvantages It does not work at night. Very diffuse source means low energy production. Only areas of the world with lots of sunlight are suitable for solar power

generation They need great lands creating high temperatures below the panels


Wind Plant

5.2.2 Electric energy. Power Stations Diagram

Primary Energy

Wind Plant Advantages It is available over a greater area than occurs with fossil fuels. There is no air pollution after manufacture. Modern wind energy converter systems can be set up for individual houses. Wind energy produces more energy per area of land than other energy

sources. Disadvantages Modern wind energy systems are expensive, although the source is free. They can be rather ugly or the noise of the rotor could be annoying if the

installation is located close to homes or workplaces. The wind does not blow all the time. Potential TV interference caused by rotor.



Tide Energy Diagram

Primary Energy

5.2.2 Electric energy. Power Stations Tide Energy Advantages Tides are free once the power station has been built and will not run

out. No greenhouse gases are produce. We know exactly when the tides happen so we know when electricity

will be made. Disdvantages Dams may not be good for plants and animals that live nearby. The tides only happen twice a day, so can only produce electricity for

that time.

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Wave Energy

Primary Energy


Wave Energy Advantages Waves are free and will not run out so the cost is in building the power station. Wave power does not produce greenhouse gases. There are very few safety risks with wave power generation. Disdvantages Waves can be big or small so you may not always be able to generate

electricity. You need to find a way of transporting the electricity from the sea onto the land. Not many people have tried to generate electricity this way yet so the

equipment is expensive.


Biomass .

Natural biomass

Dry Biomass Waste from industrial process

Wet Biomass Human or animal disposal

Energetic Crops High Energy Plants Are cultivated

Diagram

Steam pressure


Biomass Advantages The fuel is cheap and can use things that we might

otherwise throw away. We can find waste everywhere and should not run out. Disadvantages When the fuel is burned greenhouse gases are made which

pollute the environment. Sometimes people grow biomass crops where we could

grow food. We may not have enough space to grow enough biomass

fuel.


Geothermal Energy Diagram

Steam pressure


Geothermal Energy Advantages Geothermal energy does not produce greenhouse gases The energy source is free and will not run out Disadvantages There are not many places where we can build geothermal power

stations Harmful gases and minerals may occasionally come up from the

ground below. These can be difficult to control.

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5.2.2 Electric energy. Power Stations Fusion Energy the Future Energy

Steam pressure


Source Renowable/ Non reno.

Type of central

Advantages Disavantages

DC/CC

Wind

CC

Thermical

Water

Radioactive waste

Tide

Once we create electricity we have to transport it to the final users. Nowadays we use these elements:

5.2.3 Electric energy. Distribution

Transformer

Pylons

Transformer

Final User

Why do we need a transformer???


All conductors have resistance, and its opposition to the intensity creates HEAT !!!


so our electric distribution could be a huge heater!!!!

P=I2R

Therefore, in order to transmit high electric power, we have to decrease the intensity by increasing the voltage


So, with high voltage distribution, we lose less calorific energy and thanks to that we can use thinner cables

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Exercise 8 Calculate the % of energy wasted in calorific energy when we transport 1250 kw with a cable that has 10 Ohm if:

Voltage is 250kV Voltage is 25 KV

5.2.3 Electric energy. Distribution Exercise 8 Calculate the % of energy wasted in calorific energy when we transport

1250 MW with a cable that has 10 Ohm if: Voltage is 250kW


Exercise 8 Calculate the % of energy wasted in calorific energy when we transport

1250 MW with a cable that has 10 Ohm if: Voltage is 25 KV


But, how does it work? 5.2.3 Electric energy. Distribution

Any transformer is based in the relation between the magnetic field created by two reels that have the same nucleus


Nucleus

Reel Reel

This is the relation between the I and V in each Reel:


Nucleus

Entrance Exit

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Therefore, if we want to have a high volt current, we have to increase the number of spirals of the 2º reel (N2)

5.2.3 Electric energy. Distribution Electricity arrives at home trough the

electric panel that we find close to the entrance door


Electric meter

HOME

Basic electric panel High electric panel

In the control panel we find: 1º The ICP: This circuit

break is placed by your electric company to control that you don’t pass the top consume that you have contracted

5.2.3 Electric energy. Distribution In the control panel we find: 1º The IGA: This circuit

break allows us to break the hole circuit with one switch


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In the control panel we find: 1º The Differential switch :

This circuit break protects us against a electric discharge

5.2.3 Electric energy. Distribution In the control panel we find: 1º PIA: These circuit

breakers control the different circuits that we have at home


5.3 Consume In Spain, we use too much fossil energy

to produce electricity

5.1.3 Consume

Thes

e ar

e th

e m

ain

cent

rals

in S

pain

5.3 Consume This is the evolution of the self energy

supply for the last 35 years

Year Self energy Supply

1975 22,6 1985 38,9 1995 28,0 1998 25,6 2003 22,1 2008 21,6 Fuentes: 1975-1998:,[6] 2003:[7] 2008: Ministerio de Industria, Turismo y Comercio[1

0 10 20 30 40

1975

1985

1995

1998

2003

2008

Fuen

tes:

19

75-1

998:

,

Self Energy Supply

5.3 Consume This is the use of the different forms

of energy.

Fuente de energía

Producción 2007 (ktep) 2007 % Producción 2008

(ktep) 2008 % 2008/2007

Carbón 5.865 19,3 4.374 14,2 -25,4 Petróleo 143 0,5 127 0,4 -11,2 Gas natural 16 0,1 14 0,0 -10,9 Nuclear 14.360 47,3 15.368 50,0 7,0 Hidráulica 2.342 7,7 2.001 6,5 -14,5 Otras energías renovables 7.624 25,1 8.841 28,8 16,0

Total 30.348 100,0 30.725 100,0 1,2

Coal ; 14,2 Oil; 0,4 Gas; 0

Nuclear; 50

Hydro; 6,5

Renowable; 28,8

2008 consume

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5.1.1 1º Exercise Solution

Yogurt 85 kcal Big Mac 498 kcal

Bread 250kcal Apple 59 kcal

Biscuits 450 kcal Orange Fanta

58 kcal

Cereals 400kcal Oil 900kcal

Chips 234kcal Butter 760 kcal

Investigate the energy that these foods have per 100 gr:

Solution

5.1.1 Energy. Units

2º Exercise Solution: • Calculate the energy of a Coke in joules.

• Calculate the energy measured in kwh that we absorb in 2h when we drink 2 Cokes?

5.1.1 Energy. Units

2º Exercise Solution: • If we use a 100W lamp, and we use Cokes to provide energy, how many Cokes do we need per second?

Exercise 5.1.2 3 Exercise Forms and Sources 3º Exercise: a) Explain the difference between the concepts of source

and form of energy. Both terms are related to energy. Energy is the capacity

of an object to do a work, and it can be stored in different forms of energy, like electric, chemical, mechanical, etc.

A source of energy is how this form of energy is stored for its use around us. A form of energy is a energy resource, i.e. wind, sun light, etc.

So, coal is a source of energy because it store a lot of useful chemical energy liberated when we burn it

5.1.2 3 Exercise Forms and Sources 3º Exercise: a) Define the six groups of energy sources, and give four examples of each. Define the six groups of energy sources, and give four examples of

each. Renewable (Origin): Inexhaustible sources which can be used

continuously. Ex: Wind, waves, sun and firewood. Non renewable (Origin): Exhaustible sources which can be exhausted as

years go. Ex: Oil, uranium, natural gas and coal. Traditional (Historical use): This type provides a big amount of global

energy. Ex: Hydraulic, coal, uranium and oil. Alternative (Historical use): This type provides energy and it´s easier to

obtain than traditional energy. Ex: Wind, solar, biomass and geothermal. Primary (Transformation): This type is obtained from the environment

whitout any kind of transformation. Ex: Gas, solar, coal and wind. Secondary (Transformation): This source is obtained after the

transformation of a primary source. Ex: Electricity, gas, petrol and oil.

5.1.2 Exercise 5 sol Forms and Sources 5º Exercise: Make a list of 20 objects indicating the source of energy

used and the energy obtained . For example: TV-Electricity

Object Energy Source Energy obtained TV Electricity Light

Washing machine Electric energy Mechanical

Radiator Electric energy Calorific

Computer electric light

Fridge Electric energy Mechanical-Calorific

Toaster Electric energy Calorific

Bulb Electric energy light

Dishwasher Electric energy Mechanical

Transformer Electric energy Electrical

Furnace Electrical energy Calorific

Back

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Object Energy source Energy obtained Fridge Electricity Calorific Computer Electricity Light Lamp Electricity Light Microwave Electricity Light- Calorific Toaster Electricity Calorific Vitro Electricity Calorific Deep fryer Electricity Calorific Loudspeaker Electricity Sound

Freezer compartment Electricity Calorfic Thermal printer Electricity Calorific Games console Electricity Light Coffee maker Water and Electricity Calorific Calculator Electricity Light Mobile phone Electricity Light Telephone Electricity Sound Car Electricity Mechanical Alarm clock Electricity Sound Dishwasher Electricity Calorific and Mechanical Washing machine Electricity Calorific and Mechanical Alarm Electricity Sound

5.2.1 Exercise Sol. Electric energy. Production 1º Exercise: Compare the use of electricity at home with the use of

coal, oil, gas, solar, wind, geothermal, uranium.

Coal produces a lot of smoke and dust if we use it to heat or cook. Also requires a lot of space to store it.

Oil is used to heat houses but is really dangerous if we use it to cook or to create light.

Solar energy can be used to heat water, but it doesn’t get really hot. We can use it to cook but it is too slow.

Gas is used to cook but it’s quite dangerous and is more difficult to clean. We use it to heat water and houses.

Wind, geothermal and uranium can’t be used directly at home, so we need to get electricity from them.

5.2.1 Exercise Sol. Electric energy. Production 2º Exercise: What do we mean when we say that the electricity is clean? Electricity is usually defined as clean energy because we

can use it at home anytime anyplace. It doesn’t create any dust, gas or smell as does coal, gas or oil.

But we have to remember that to create electricity we are different energy sources like coal, oil, nuclear, etc that have several disadvantages like pollution, nuclear waste, environment destruction, etc.

Back

Nuclear power station 5.2.2 Nuclear Power Stations

Steam

Mine Reactor

Boiler

Turbine

Generator

Transformer

Cooling

Mechanical Energy

Electricity

Cold Water

Heat

Pylons

High Volt

Steam

Uranium

Nuclear

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The water from the river is stored in a dam. The water is released has high energy thanks to the height, so it moves the turbine. The mechanical energy obtained is transformed into electricity inside the generator. This electricity is transformed into high voltage electricity in a transformer. This electricity is connected to the pylons and transmitted to the electric grid

5.2.2 Hydro Power Stations

River Dam

Turbine Generator Transformer

Mechanical Energy Electricity

Water high pressure

Pylons

High Volt

Water

River

Water

Back

Solar Tower power station 5.2.2 Solar Tower Power Stations

Steam

Sun Heliostats

Boiler

Turbine

Generator

Transformer

Cooling

Mechanical Energy

Electricity

Cold Water

Light

Pylons

High Volt

Steam

Light

Back

Photovoltaic power station 5.2.2 Photovoltaic Power Stations

Alternate Current

Sun Solar panel photovoltaic

Inverter Electric current

Light

Back Wind power station 5.2.2 Wind Power Stations

Wind Rotor

Gear Box Generator

Transformer

Multiplied Mechanical Energy

Electricity

Pylons

High Volt

Mechanical energy

Mechanical energy

Back

Tide Power Station 5.2.2 Tide Power Stations

Sea Dam

Turbine

Generator

Transformer

Mechanical Energy Electricity

Water high pressure

Pylons

High Volt

Tide Water raise

Water

Back Biomass power station

5.2.2 Biomass Power Stations

Steam

Biomass Furnace

Boiler

Turbine

Generator

Transformer

Cooling

Mechanical Energy

Electricity

Cold Water

Heat

Pylons

High Volt

Steam

Bio fuel

Back

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Geothermal power station 5.2.2 Geothermal Power Stations

Steam

Water pump

Lava

Turbine

Generator

Transformer

Cooling

Mechanical Energy

Electricity

Cold Water

Pylons

High Volt

Steam

Water

Back

Unidad 3 ESO Energia

Technology

Transcript of Unidad 3 ESO Energia