Topic 1: Introduction to Energy

CN604: Energy System Page 1

Introduction

Energy is one of the most fundamental parts of our universe.

We use energy to do work. Energy lights our cities. Energy powers

our vehicles, trains, planes and rockets. Energy warms our homes,

cooks our food, plays our music, gives us pictures on television.

Energy powers machinery in factories and tractors on a farm.

Energy from the sun gives us light during the day. It dries our

clothes when they're hanging outside on a clothes line. It helps plants grow. Energy stored in plants is

eaten by animals, giving them energy. And predator animals eat their prey, which gives the predator

animal energy.

Everything we do is connected to energy in one form or another.

Energy is defined as: "the ability to do work."

When we eat, our bodies transform the energy stored in the food into energy to do work. When we

run or walk, we "burn" food energy in our bodies. When we think or read or write, we are also doing

work. Many times it's really hard work!

Energy causes things to happen around us. Look out the window.

During the day, the sun gives out light and heat energy. At night, street lamps use electrical energy to

light our way.

When a car drives by, it is being powered by gasoline, a type of stored energy.

The food we eat contains energy. We use that energy to work and play.

We learned the definition of energy in the introduction:

"Energy Is the Ability to Do Work."

Energy can be found in a number of different forms. It can be chemical energy, electrical energy, heat

(thermal energy), light (radiant energy), mechanical energy, and nuclear energy.

Energy is measured in many ways.

One of the basic measuring blocks is called a Btu. This stands for British thermal unit and was invented

by, of course, the English.

Btu is the amount of heat energy it takes to raise the temperature of one pound of water by one

degree Fahrenheit, at sea level.

One Btu equals about one blue-tip kitchen match.

Topic 1: Introduction to Energy

CN604: Energy System Page 2

One thousand BTU roughly equals: One average candy bar or 4/5 of a

peanut butter and jelly sandwich.

It takes about 2,000 BTU to make a pot of coffee.

Energy also can be measured in joules. Joules sounds exactly like the

word jewels, as in diamonds and emeralds. A thousand joules is equal to a

British thermal unit.

1,000 joules = 1 Btu

So, it would take 2 million joules to make a pot of coffee.

The term "joule" is named after an English scientist James Prescott Joule

who lived from 1818 to 1889. He discovered that heat is a type of energy.

One joule is the amount of energy needed to lift something weighing one pound to a height of nine

inches. So, if you lifted a five-pound sack of sugar from the floor to the top of a counter (27 inches),

you would use about 15 joules of energy.

Around the world, scientists measure energy in joules rather than Btus. It's much like people around

the world using the metric system of meters and kilograms, instead of the English system of feet and

pounds.

Like in the metric system, you can have kilojoules — "kilo" means 1,000.

1,000 joules = 1 kilojoule = 1 Btu

Do you know that…?

A piece of buttered toast contains about 315 kilojoules (315,000 joules) of energy. With that energy

you could:

Jog for 6 minutes

Bicycle for 10 minutes

Walk briskly for 15 minutes

Sleep for 1-1/2 hours

Run a car for 7 seconds at 80 kilometers per hour (about 50 miles per hour)

Light a 60-watt light bulb for 1-1/2 hours

Or lift that sack of sugar from the floor to the counter 21,000 times!

Topic 1: Introduction to Energy

CN604: Energy System Page 3

Electric Energy

Electricity figures everywhere in our lives.

Electricity lights up our homes, cooks our food,

powers our computers, television sets, and

other electronic devices. Electricity from

batteries keeps our cars running and makes our

flashlights shine in the dark.

Here's something you can do to see the

importance of electricity. Take a walk through

your school, house or apartment and write

down all the different appliances, devices and

machines that use electricity. You'll be amazed

at how many things we use each and every day

that depend on electricity.

But what is electricity? Where does it come

from? How does it work? Before we

understand all that, we need to know a little bit

about atoms and their structure.

All matter is made up of atoms, and atoms are made up of smaller particles. The three main particles

making up an atom are the proton, the neutron and the electron.

Electrons spin around the center, or nucleus, of atoms, in the same way the moon spins around the

earth. The nucleus is made up of neutrons and protons.

Electrons contain a negative charge, protons a positive charge. Neutrons are neutral – they have

neither a positive nor a negative charge.

There are many different kinds of atoms, one for each type of element.

An atom is a single part that makes up an element. There are 118

different known elements that make up every thing! Some elements like

oxygen we breathe are essential to life.

Each atom has a specific number of electrons, protons and neutrons. But

no matter how many particles an atom has, the number of electrons

usually needs to be the same as the number of protons. If the numbers

are the same, the atom is called balanced, and it is very stable.

DID YOU KNOW?

Energy makes everything happen and can be

divided into two types:

Stored energy is called potential energy.

Moving energy is called kinetic energy.

With a pencil, try this example to know the

two types of energy.

Put the pencil at the edge of the desk and

push it off to the floor. The moving pencil

uses kinetic energy.

Now, pick up the pencil and put it back on

the desk. You used your own energy to lift

and move the pencil. Moving it higher than

the floor adds energy to it. As it rests on

the desk, the pencil has potential energy.

The higher it is, the further it could fall.

That means the pencil has more potential

energy.

Topic 1: Introduction to Energy

CN604: Energy System Page 4

So, if an atom had six protons, it should also have six electrons. The

element with six protons and six electrons is called carbon. Carbon is

found in abundance in the sun, stars, comets, atmospheres of most

planets, and the food we eat. Coal is made of carbon; so are diamonds.

Some kinds of atoms have loosely attached electrons. An atom that loses

electrons has more protons than electrons and is positively charged. An

atom that gains electrons has more negative particles and is negatively

charge. A "charged" atom is called an "ion."

Electrons can be made to move from one atom to another. When those

electrons move between the atoms, a current of electricity is created. The electrons move from one

atom to another in a "flow." One electron is attached and another electron is lost.

This chain is similar to the fire fighter's bucket brigades in olden times. But instead of passing one

bucket from the start of the line of people to the other end, each person would have a bucket of

water to pour from one bucket to another. The result was a lot of spilled water and not enough

water to douse the fire. It is a situation that's very similar to electricity passing along a wire and a

circuit. The charge is passed from atom to atom when electricity is "passed."

Scientists and engineers have learned many ways to move electrons off of atoms. That means that

when you add up the electrons and protons, you would wind up with one more proton instead of

being balanced.

Since all atoms want to be balanced, the atom that has been "unbalanced" will look for a free

electron to fill the place of the missing one. We say that this unbalanced atom has a "positive

charge" (+) because it has too many protons.

Since it got kicked off, the free electron moves around waiting for an unbalanced atom to give it a

home. The free electron charge is negative, and has no proton to balance it out, so we say that it has

a "negative charge" (-).

So what do positive and negative charges have to do with electricity?

Scientists and engineers have found several ways to create large numbers of positive atoms and free

negative electrons. Since positive atoms want negative electrons so they can be balanced, they have

a strong attraction for the electrons. The electrons also want to be part of a balanced atom, so they

have a strong attraction to the positive atoms. So, the positive attracts the negative to balance out.

The more positive atoms or negative electrons you have, the stronger the attraction for the other.

Since we have both positive and negative charged groups attracted to each other, we call the total

attraction "charge."

Energy also can be measured in joules. Joules sounds exactly like the word jewels, as in diamonds

and emeralds. A thousand joules is equal to a British thermal unit.

Topic 1: Introduction to Energy

CN604: Energy System Page 5

When electrons move among the atoms of matter, a current of electricity is created. This is what

happens in a piece of wire. The electrons are passed from atom to atom, creating an electrical

current from one end to other, just like in the picture.

Electricity is conducted through some things better than others do. Its resistance measures how well

something conducts electricity. Some things hold their electrons very tightly. Electrons do not move

through them very well. These things are called insulators. Rubber, plastic, cloth, glass and dry air

are good insulators and have very high resistance.

Other materials have some loosely held electrons, which move through them very easily. These are

called conductors. Most metals – like copper, aluminum or steel – are good conductors.

Thermal Energy

Geothermal Energy has been around for as long as the Earth has existed. "Geo" means earth, and

"thermal" means heat.

So, geothermal means earth-heat.

Have you ever cut a boiled egg in half? The egg is similar to

how the earth looks like inside. The yellow yolk of the egg is

like the core of the earth. The white part is the mantle of the

earth. And the thin shell of the egg, that would have

surrounded the boiled egg if you didn't peel it off, is like the

earth's crust.

Below the crust of the earth, the top layer of the mantle is a hot liquid rock called magma. The crust

of the earth floats on this liquid magma mantle. When magma breaks through the surface of the

earth in a volcano, it is called lava.

For every 100 meters you go below ground, the temperature of the rock increases about 3 degrees

Celsius. Or for every 328 feet below ground, the temperature increases 5.4 degrees Fahrenheit. So, if

you went about 10,000 feet below ground, the temperature of the rock would be hot enough to boil

water.

Deep under the surface, water sometimes makes its way close to the hot rock and turns into boiling

hot water or into steam. The hot water can reach temperatures of more than 300 degrees

Fahrenheit (148 degrees Celsius). This is hotter than boiling water (212 degrees F / 100 degrees C). It

doesn't turn into steam because it is not in contact with the air.

Topic 1: Introduction to Energy

CN604: Energy System Page 6

When this hot water comes up through a crack in the earth, we call it a hot

spring, like Emerald Pool at Yellowstone National Park pictured on the left. Or,

it sometimes explodes into the air as a geyser, like Old Faithful Geyser pictured

on the right.

About 10,000 years ago, Paleo-Indians used hot springs in North American for

cooking. Areas around hot springs were neutral zones. Warriors of fighting

tribes would bathe together in peace. Every major hot spring in the United

States can be associated with Native American tribes. California hot springs, like

at the Geysers in the Napa area, were important and sacred areas to tribes

from that area.

In other places around the world, people used hot springs for rest and relaxation. The ancient

Romans built elaborate buildings to enjoy hot baths, and the Japanese have enjoyed natural hot

springs for centuries.

Radiant Energy

Radiant energy is the energy of electromagnetic waves. The quantity of radiant energy may be

calculated by integrating radiant flux (or power) with respect to time and, like all forms of energy, its

SI unit is the joule. The term is used particularly

when radiation is emitted by a source into the

surrounding environment. Radiant energy may

be visible or invisible to the human eye.

The term "radiant energy" is most commonly

used in the fields of radiometry, solar energy,

heating and lighting, but is also sometimes used

in other fields (such as telecommunications). In

modern applications involving transmission of

power from one location to another, "radiant

energy" is sometimes used to refer to the

electromagnetic waves themselves, rather than

their energy (a property of the waves). In the past, the term "electro-radiant energy" has also been

used.

Radiant energy is used for radiant heating. It can be generated electrically by infrared lamps, or can

be absorbed from sunlight and used to heat water. The heat energy is emitted from a warm element

(floor, wall, overhead panel) and warms people and other objects in rooms rather than directly

heating the air. Because of this, the air temperature may be lower than in a conventionally heated

building, even though the room appears just as comfortable.

Topic 1: Introduction to Energy

CN604: Energy System Page 7

Chemical Energy

Chemical energy is one form of potential energy, along with mechanical

energy, gravitational energy, nuclear energy and electrical energy. All

of these forms of energy are stored within an object and are converted

to forms of kinetic energy when a force or change is applied. The

different forms of kinetic energy are radiant energy, which includes

light, x-rays and radio waves, heat, motion and sound.

As stated by the first law of thermodynamics, energy can neither be

created nor destroyed; it can only be converted from one form to

another. During chemical reactions, molecules can be created or

destroyed. If a product is created, the chemical energy is stored in the

bonds that make up the molecules. If something is broken down, the chemical energy is released,

usually as heat. If a reaction releases energy, it is called exothermic, and if it absorbs energy, it is called

endothermic.

One example of chemical energy is that found in the food that we eat. Energy is stored in the bonds of

the molecules that make up food. When we eat the food, the large molecules are broken down into

smaller molecules that can be used by the cells of the body. The process of breaking down and using the

food by our cells is called respiration. During respiration, the chemical energy is converted to heat,

kinetic energy, and other forms of chemical energy, like that stored in the fat cells in our body.

Food is just one example of a fuel — it is how animals, including humans, fuel their bodies. Other forms

of fuel include wood and chemicals, such as petroleum. When wood is burned, the chemical energy

within the cells of the wood break and heat is released. In the engine of a car or truck, the energy in the

gasoline is converted to heat and motion, to make

the car move.

Kinetic energy can also be converted to potential

energy. During the process of photosynthesis carried

out by plants, radiant energy, or the light from the

sun, is converted into chemical energy, which is

stored within the plant. When animals eat the plants,

the reverse reaction takes place. The bonds are

broken, which releases stored chemical energy for

the animal to use.

Topic 1: Introduction to Energy

CN604: Energy System Page 8

Stored Mechanical Energy

There are two main types of mechanical energy. They are

motion energy and stored mechanical energy.

Motion energy: This is the energy something has because it is

moving (eg a speeding cricket ball). You can feel the effect of this energy if the cricket ball hits you.

Motion energy is also called kinetic energy.

Stored mechanical energy: This is energy something has stored in it because of its height above the

ground or because it is stretched or bent or squeezed (eg in a stretched rubber band). You can feel it

when the band is released.

Stored mechanical energy is also called potential energy.

Potential Energy

An object can store energy as the result of its position. For example, the heavy ball of a demolition

machine is storing energy when it is held at an elevated position. This stored energy of position is

referred to as potential energy. Similarly, a drawn bow is able to store energy as the result of its

position. When assuming its usual position (i.e., when not drawn), there is no energy stored in the

bow. Yet when its position is altered from its usual equilibrium position, the bow is able to store

energy by virtue of its position. This stored energy of position is referred to as potential energy.

Potential energy is the stored energy of position possessed by an object.

Topic 1: Introduction to Energy

CN604: Energy System Page 9

Nuclear Energy

Another major form of energy is nuclear energy, the energy that is trapped inside each atom. One of

the laws of the universe is that matter and energy can't be created nor destroyed. But they can be

changed in form.

Matter can be changed into energy. The world's most famous scientist, Albert Einstein, created the

mathematical formula that explains this. It is:

This equation says:

E [energy] equals m [mass] times c2 [c stands for the velocity or the speed of light. c2 means c times

c, or the speed of light raised to the second power — or c-squared.]

Please note that some web browser software may not show an exponent

(raising something to a power, a mathematical expression) on the Internet.

Normally c-squared is shown with a smaller "2" placed above and to the right

of the c.

Scientists used Einstein's famous equation as the key to unlock atomic

energy and also create atomic bombs.

The ancient Greeks said the smallest part of nature is an atom. But they did

not know 2,000 years ago about nature's even smaller parts.

Atoms are made up of smaller particles -- a nucleus of protons and neutrons, surrounded by

electrons which swirl around the nucleus much like the earth revolves around the sun.

An atom's nucleus can be split apart. When this is done, a tremendous amount of energy is released.

The energy is both heat and light energy. Einstein said that a very small amount of matter contains a

very LARGE amount of energy. This energy, when let out slowly, can be harnessed to generate

electricity. When it is let out all at once, it can make a

tremendous explosion in an atomic bomb.

A nuclear power plant (like Diablo Canyon Nuclear Plant

shown below) uses uranium as a "fuel." Uranium is an

element that is dug out of the ground many places around

the world. It is processed into tiny pellets that are loaded

into very long rods that are put into the power plant's

reactor.

Topic 1: Introduction to Energy

CN604: Energy System Page 10

The word fission means to split apart. Inside the reactor of an atomic power plant, uranium atoms

are split apart in a controlled chain reaction.

In a chain reaction, particles released by the splitting of the atom go off and strike other uranium

atoms splitting those. Those particles given off split still other atoms in a chain reaction. In nuclear

power plants, control rods are used to keep the splitting regulated so it doesn't go too fast.

If the reaction is not controlled, you could have an atomic bomb. But in atomic bombs, almost pure

pieces of the element Uranium-235 or Plutonium, of a precise mass and shape, must be brought

together and held together, with great force. These conditions are not present in a nuclear reactor.

The reaction also creates radioactive material. This material could hurt people if released, so it is

kept in a solid form. The very strong concrete dome in the picture is designed to keep this material

inside if an accident happens.

This chain reaction gives off heat energy. This heat energy is used to boil water in the core of the

reactor. So, instead of burning a fuel, nuclear power plants use the chain reaction of atoms splitting

to change the energy of atoms into heat energy.

Power plant drawing courtesy Nuclear Institute

This water from around the nuclear core is sent to another section of the power plant. Here, in the heat

exchanger, it heats another set of pipes filled with water to make steam. The steam in this second set of

pipes turns a turbine to generate electricity. Below is a cross section of the inside of a typical nuclear

power plant.

Topic 1: Introduction to Energy

CN604: Energy System Page 11

Another form of nuclear energy is called

fusion. Fusion means joining smaller nuclei

(the plural of nucleus) to make a larger

nucleus. The sun uses nuclear fusion of

hydrogen atoms into helium atoms. This gives

off heat and light and other radiation.

In the picture to the right, two types of

hydrogen atoms, deuterium and tritium,

combine to make a helium atom and an extra particle called a neutron.

Also given off in this fusion reaction is energy! Thanks to the University of California, Berkeley for the

picture.

Scientists have been working on controlling nuclear fusion for a long time, trying to make a fusion

reactor to produce electricity. But they have been having trouble learning how to control the

reaction in a contained space.

What's better about nuclear fusion is that it creates less radioactive material than fission, and its

supply of fuel can last longer than the sun.

Energy conservation is…

Reduction in the amount of energy consumed in a process or system, or by an organization or

society, through economy, elimination of waste, and rational use.

Energy should be conserved since we are consuming disproportionate amount of energy and that day

is not far when all our Non-Renewable resources will expire forcing us to rely just on Renewable

Sources. The electricity that we use comes from nuclear power, coal power plants, Oil that we use to

run our vehicles are fossil fuels that were created million of years ago from decaying plants. When

burned they emit carbon-dioxide which is harmful to humans and the environment.

Apart from these it also helps us to save money, mitigates the numerous

adverse environmental and social impacts associated with energy production

and consumption. These include air pollution, acid rain and global warming, oil

spills and water pollution, loss of wilderness areas, construction of new power

plants, foreign energy dependence and the risk of international conflict over

energy supplies. Energy conservation extends the lifetime of equipment and

reduces the maintenance cost by operating less hours and at less than

maximum capacity.

Topic 1: Introduction to Energy

CN604: Energy System Page 12

Reduce Consumption on Non-Renewable Sources

Consumption on Non-Renewable sources must be reduced as much as possible.

1. Resource Depletion: By using these resources in excess, they are going to deplete one day and

will take another millions of years to form again.

2. Save Money: Usage of fluorescent bulbs , solar electricity may cost expensive initially but prove

to be cost-effective in the long run. Many energy efficiency and conservation measures are

better investments than the stock market or bank interest.

3. Reduce Carbon-dioxide: If Non-Renewable resources are used up to the limit they may also help

in reducing the carbon-dioxide. Pollution from nuclear and coal power plants cause diseases like

asthma, emphysema etc.

4. Climate Change : Due to increase int the rate of these resources it also affect the climate

greatly, Drought, Severe storms, floods, land loss, erosion of soil and heat deaths are few

examples of climate change.

5. Ozone Layer Depletion: Ozone layer in the atmosphere protect us from ultraviolet rays from

reaching the earth thus, making life on the earth possible.

6. Adverse affect on humans and the environment: Extraction of Uranium and Coal from beneath

the earth cause huge affect to the lives of cola miners. These people have high cancer death

rates. They also harm the environment and agricultural lands.

7. Acid Rain: Coal power plants and vehicles emit sulfur dioxide (SO2) and nitrous oxides (NOx).

These travel beyond the local area and are harmful to the health throughout whole regions.

When SO2/NOx and water vapor mix under certain conditions, sulfuric acid and nitric acid, know

as acid rain, are formed. This is very harmful to the lungs. It kills fish in lakes, corrodes property

(buildings, monuments, cars), harms the soil (releasing toxins), and harms trees and crops.

8. Global Warming: With so much dependence on Non renewable sources, global warming is

taking place all over the world and the result which is glaciers are melting which is causing the

rise in the sea level.

Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the

amount of energy required to provide products and services. For example, insulating a home allows a

building to use less heating and cooling energy to achieve and

maintain a comfortable temperature. Installing fluorescent

lights or natural skylights reduces the amount of energy

required to attain the same level of illumination compared to

using traditional incandescent light bulbs. Compact fluorescent

lights use two-thirds less energy and may last 6 to 10 times

longer than incandescent lights. Improvements in energy

efficiency are most often achieved by adopting a more

efficient technology or production process.

There are various different motivations to improve energy

Topic 1: Introduction to Energy

CN604: Energy System Page 13

efficiency. Reducing energy use reduces energy costs and may result in a financial cost saving to

consumers if the energy savings offset any additional costs of implementing an energy efficient

technology. Reducing energy use is also seen as a key solution to the problem of reducing emissions.

According to the International Energy Agency, improved energy efficiency in buildings, industrial

processes and transportation could reduce the world's energy needs in 2050 by one third, and help

control global emissions of greenhouse gases.[3]

Energy efficiency and renewable energy are said to be the twin pillars of sustainable energy policy.[4]

In many countries energy efficiency is also seen to have a national security benefit because it can be

used to reduce the level of energy imports from foreign countries and may slow down the rate at

which domestic energy resources are depleted.

Renewable Energy & Non Renewable Energy

The energy sources from which we gain energy are classified broadly into 2

groups namely:

Renewable and Non-Renewable (Fossil Fuels)

Renewable Sources

Renewable Sources include solar, wind, geothermal, biomass and hydro power. Solar energy is the

energy that we get from the sun. It is the major source of energy among all the nations. However,

there are major drawbacks related to limited production as well as high costs that don't allow people

to use it in a wider scale. Solar energy is responsible for growth of plants and indirectly, the existence

of all animal life. Wind energy is used in large farm fields where they can use windmills to provide

power for the accomplishment of agricultural tasks has contributed to the growth of civilization.

This apart from solar is another clean and renewable source of energy. The major drawback is that it

can be used only in the coastal regions and can be noisy too. Geothermal energy is the energy stored

inside the earth. The center of the earth has temperature about 6000 degrees F. The heat that is

stored inside the earth is used to produce steam, which is then used to drive electrical generators. The

main advantage of it is that it does not cause any pollution and no fuel is needed. However, hazardous

steams and gases may come out from bottom that may cause harm to mankind.

Topic 1: Introduction to Energy

CN604: Energy System Page 14

Biomass energy is the energy that we get from the organic materials. Biomass is simply the conversion

of stored energy in plants into energy that we can use. Thus, burning wood is a method of producing

biomass energy. "Bioconversion" uses plant and animal wastes to produce "biofuel" such as methanol,

natural gas, and oil.

It in turns causes pollution when you burn them but is

relatively cheap and freely available. Hydroelectric energy is

the use of running of water to generate electricity. To trap

this energy a dam is built usually in a river or lake and water

is allowed to flow through tunnels in the dam to turn the

turbines and thus drive generators. No waste or pollution is

caused and power can be generated through out the year

but if the dam is built it may cause the flood in the large area and therefore getting the suitable site

may be difficult.

Non-Renewable Sources

Non-Renewable Sources include fossil fuels (Coal, Oil and gas) and Nuclear energy. They're called fossil

fuels because they were formed over millions and millions of years by the action of heat from the

Earth's core and pressure from rock and soil on the remains (or "fossils") of dead plants and animals.

Fossil fuels are relatively easy to use to generate energy because they only require a simple direct

combustion. However, a problem with fossil fuels is their environmental impact. When used on a

larger scale they may deplete from the earth after some years and also cause the great deal of air

pollution.

Coal is crushed to a fine dust and burnt. Oil and gas can be burnt directly. Although very large amount

of electricity can be produced at one place, it has a lot of disadvantages. The major drawback is the

pollution which in turn causes greenhouse effect which may lead to global warming. Also, coal fired

power stations need huge amount of fuel. With the large drawbacks of fossil fuels, scientists across

the world are moving there focus from fossil fuels to Nuclear energy.

Non renewable energy source is the element uranium, whose atoms we split (through a process called

nuclear fission) to create heat and ultimately electricity. Most of the nations have started building

nuclear reactors in order to avoid using fossil fuels which contribute to global warming. Some military

ships and submarines even have nuclear power plants for engines. Nuclear power produces around

11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel,

without the pollution that you'd get from burning fossil fuels. Nuclear power is reliable and does not

produce smoke or waste but if any thing goes wrong, a nuclear accident can be a major disaster.

Topic 1: Introduction to Energy

CN604: Energy System Page 15

People all across the globe use these energy sources to generate electricity for homes, business,

factories and schools. We use this energy to light bulb, run computer, refrigerators, washing machines

and air conditioners etc. We use energy to run our cars and trucks. Both the gasoline used in our cars,

and the diesel fuel used in our trucks are made from oil. Since, renewable sources are not used on much

wider scale and use of Non-renewable sources cause pollution to the environment and may extinct if

used in a hazardous manner, so the need of the hour is to conserve these resources and use them in an

efficient manner to minimize the wastage and making this planet a better place to live in.