SUBJECT : PHYSICS
TOPIC : green energy and
energy conservation .
CLASS : 11TH
MADE BY : ASWIN KUMAR.R

TYPES OF ENERGY
 RENEWABLE ENERGY:
Renewable energy can be generated continuously
practically without decay of source.
Some examples are :
• Solar energy , Wind energy , Geothermal energy ,
Hydro energy.
NON-RENEWABLE ENERGY:
Non-renewable energy is energy that comes from the
ground and is not replaced in a relatively short
amount of time.
e.g. energy generated from combustion of fossil fuels
, coal , gas etc.

WHAT IS ENERGY ?
 Energy lights our cities, powers our vehicles, and
runs machinery in factories. It warms and cools our
homes, cooks our food, plays our music, and gives
us pictures on television.
 Energy is defined as the ability or the capacity to
do work.

WHY TO CONSERVE IT ?
We have limited resources available on earth.
 Our demands are continuously increasing day
by day.
 It is possible that someday most of the non-
renewable resources will be exhausted and we
will have to switch over to alternate energy

We save our money
when we save energy.
We reduce pollution
when we save energy.
We save our energy
when we save energy.

WHAT WE CAN DO ?
 RECYCLE - compositing waste materials into new
products to prevent waste of potentially useful
materials.
 Turn off all electronic devices that are not in use.
Not only turn them off but try to remember to unplug
them. You will be surprised how much you will save
with this simple step!
 Replace old light bulbs with energy saving
fluorescent bulbs. They may cost more, but will save
you much more in the long run.

At Home
•We should not keep lights
unnecessarily switched on.
• Reduce the energy your
appliances consume by analyzing
star ratings.
• Improve your water heating
efficiency to reduce energy costs.
At Public
Places
• Switch of the fans and lights in
the places like bus terminal and
railway stations when not
necessary.
• Switch off the street lights.
• Big Hoardings, lightened up for
the whole evening and nights are
other wastage of power which can
be and should be avoided

HOW WILL IT HELP ?
 Let’s Take an simple example :
• let us assume electricity is available for Rs.4.00 per
unit , a 100 watt bulb is used for 8 hrs a day then:
•If we replace a 100 watt bulb with 22 watt CFL ,
• The annual saving would be…
• Power saved : 100W– W = 78W

GREEN ENERGY
Renewable energy is the energy from natural
sources and minerals like sun, wind, and tides
nuclear and hydroelectric power. The
renewable energy is named so because it is
environment friendly and it can replace non
renewable energies like oil and coal

FORMS & TYPES OF RENEWABLE ENERGY
 wind power
Wind has been an energy source for a very long
time. It was used by the Chinese about 4000 years ago
to pump water for their crops and by sailors to sail
around the world. The energy in wind can be used by
making a tower which stands high above the sea level
with a large propeller at the top. What the wind does is
it basically blows the propeller round and round which
in turn helps produce electricity. By building not just
one but multiple of these towers you can produce more
electricity at once. The most suitable area to build
these wind turbines would be in coastal areas, tops of
hills, open fields or basically anywhere the winds are
strong and continuous.

ADVANTAGES AND DISADVANTAGES OF WIND
POWER :
 wind as we all know is free and can’t be purchased
anywhere, therefore wind power is very cost
efficient. It produces no greenhouse gases or waste that
could cause harm to the environment.
 the land beneath the tower can still be used for farming
since it doesn’t take up a lot of space.
Last but not the least wind power is a very good way of
providing energy to remote areas.

 these wind farms are usually near the coast, and
near the coast means higher land prices. Some
people feel that these tall towers destroy the
beauty of the land.

DISADVANTAGES
 Some other disadvantages of these wind farms are they
can affect television reception for people in close
proximity to them, they can be noisy, they can kill birds,
and lastly the wind cannot always be predicted.

HYDROPOWER
 Water is about 800 times denser than air and therefore even a
small stream of water can produce a reasonable amount of
energy. Water energy can be in many different forms such as
hydroelectric energy, micro hydro, hydro power without
dams, and ocean energy. Today there are many hydroelectric
power stations in the world and together they are providing
about 20% electricity across the globe. Solar energy is also
one of the oldest renewable sources in the world. This energy
is taken from the sun in the form of solar radiation. .

THE SOLAR POWER
 Solar energy technologies use the sun's energy
and light to provide heat, light, hot water,
electricity, and even cooling, for homes,
businesses, and industry.

There are basically three ways that we can use the
sun’s energy.
 The first is by solar cells in which photovoltaic or
photoelectric cells are used to convert light directly into
electricity
 The second is solar water heating in which the heat from
the sun is used to warm the water in glass panels on the
roof therefore no longer requiring gas or electricity to heat
the water.
 The third is solar furnaces which use mirrors to capture the
sun’s energy into a congested place to produce high
temperatures. These solar furnaces can be used to cook
food.

THERE
ARE A VARIETY OF TECHNOLOGIES THAT HAVE BEEN DEVELOPED TO
TAKE ADVANTAGE OF SOLAR ENERGY. THESE INCLUDE:
 Photovoltaic Systems
Producing electricity directly from sunlight.
 Solar Hot Water
Heating water with solar energy.
 Solar Electricity
Using the sun's heat to produce electricity.
 Passive Solar Heating and Day lighting
Using solar energy to heat and light buildings.
 Solar Process Space Heating and Cooling
Industrial and commercial uses of the sun's heat

WHY IS RENEWABLE ENERGY IMPORTANT?
 Renewable energy is important because of the benefits it
provides. The key benefits are:
 Environmental Benefits
 Energy for our children's children
 Jobs and the Economy
 Energy Security

MADE BY : ASWIN KUMAR.R
CLASS : 11TH