2. ENERGY
ī Energy can neither be created nor it can
be destroyed. It can only be converted
from one form to another.
ī For example :-
âĸ In a room heater, electrical energy is converted
to thermal energy.
âĸ Turbine converts mechanical energy stored in
steam to electrical energy.
3. TyPeS of energy
Energy can be broadly divided into two
categories-
ī Renewable energy
īNon-renewable energy
4. Renewable energy
ī Renewable energy can be generated
continuously practically without decay of
source. E.g. â
ī Solar energy
ī Wind energy
ī Geothermal energy
ī Hydro energy
ī Biomass
5. Solar energy
ī Solar energy, radiant light and heat
from the sun, has been harnessed by
humans using various equipments.
ī Solar powered electrical generation
relies on heat engines and
photovoltaic's.
ī Examples :
ī Solar cooker
ī Solar heater
ī Solar cells
ī Advantages
ī Solar energy doesnât produce Carbon dioxide.
ī It have minimal impact on environment.
ī Disadvantages
ī It is not constant, it depends on weather
conditions,time,location.
SOLAR CELLS
SOLAR HEATER
6. WIND ENERGY
ī wind energy generated by wind
turbines is mainly used to generate
electricity.
ī Advantages :
ī Wind turbines (often called windmills) do
not release emissions that pollute the air or
water.
ī Disadvantages :
ī Installation and maintenance cost is very
high.
ī Only few places are there in world where
wind blow continuously throughout the
year.
WIND TURBINES
7. GEOTHERMAL ENERGY
īGeothermal energy is heat
from within the Earth. We can
recover this heat as steam or
hot water and use it to heat
buildings or generate
electricity.
īE.g.
īHot springs
īFumaroles
īGeysers
īAdvantages :
ī carbon dioxide emission levels are
very low. They release less than 1%
of the carbon dioxide.
īDisadvantages :
īInstallation cost is very high.
īRelease various kind of harmful
gases.
HOT SPRINGS
8. BIOMASS
īBiomass is organic material made
from plants and animals
(microorganisms).
īWhen burned, the chemical energy in
biomass is released as heat .
īE.g. -
īMethanol (from animal waste)
īEthanol
īBiodiesel(liquid biomass)
īAdvantages :
īEquipment(biogas plant) installation cost is
less.
īHelps in garbage reduction.
īDisadvantages :
īReleases high amount of sulphurous gases.
9. HYDRO ENERGY
ī Hydro energy is generally
generated form running
water using various
mechanical methods.
ī E.g. :
ī Dams
ī Tidal Barrages
ī Ocean Thermal Energy
Conversion (OTEC) system
ī Advantages :
ī Produces very less amount of
carbon dioxide.
ī It is also being used to control
flood and for irrigation purposes.
ī Disadvantages:
ī Natural environment is
destroyed.
Hydroelectric Dam
10. NON-RENEWABLE ENERGY
ī Non renewable energy canât be generated
again and again form the same source.
ī E.g. â
ī Petroleum products ( kerosene,petrol,diesel,etc )
ī Coal
ī Uranium
11. PETROLEUM (OIL)
ī Oil was formed from the
remains of animals and
plants that lived millions
of years ago in a marine
(water) environment
before the dinosaurs.
ī Over millions of years, the
remains of these animals
and plants were covered
by layers of sand and silt
ī Heat and pressure from
these layers helped the
remains turn into what we
today call crude oil.
ī Disadvantages :
ī Responsible for 38% of carbon
dioxide in the environment.
petrol
Crude oil
12. COAL
ī Coal is a combustible black or
brownish-black sedimentary rock
composed mostly of carbon and
hydrocarbons.
ī For millions of years, a layer of
dead plants at the bottom of the
swamps was covered by layers of
water and dirt, trapping the
energy of the dead plants.
ī The heat and pressure from the
top layers helped the plant
remains turn into what we today
call coal .
ī Disadvantages :
ī Responsible for 57% of carbon dioxide in
the air.
Coal
13. URANIUM
ī Nuclear energy is energy in the nucleus
(core) of an uranium-235 atom. Atoms
are tiny particles that make up every
object in the universe.
ī It can be released from atoms in two
ways: nuclear fusion and nuclear
fission.
ī Advantages :
ī Even a small amount can release enough energy
to light-up thousand of energy for months. (1 kg
uranium-235 corresponds to 2.7 million kg coal
equivalent.)
ī Disadvantages :
ī After using it in nuclear reactor then also it
radioactive substances is very dangerous for
human . Eg : carbonyl accident and fukushima
plant accident.
uranium
Nuclear plant
14. DIFFERENCE BETWEEN RENEWABLE AND NON-RENEWABLE
SOURCE OF ENERGY
RENEWABLE SOURCE
ī Definition : Renewable energy can
be generated continuously
practically without decay of
source.
ī Responsible for 3-4% of carbon
dioxide in environment.
ī Not a reason behind âglobal
warmingâ.
ī Example : biomass, hydro power,
wind energy, solar energy,etc.
NON-RENEWABLE SOURCE
âĸ Definition : non-renewable canât
be generated continuously
without decay of source.
âĸ Responsible for 91-94% of
carbon dioxide in environment.
âĸ Main reason behind âglobal
warmingâ.
âĸ Example : petroleum
products,coal,uranium,etc.
15. ENERGYCONSERVATION
ī Energy conservation refers to efforts made to reduce
energy consumption.
ī Energy conservation can be achieved through
increased efficient energy use or reduced
consumption from non-renewable energy sources.
ī Energy conservation is often the most economical
solution to energy shortages.
WHY TO CONSERVE ?
âĸ We have limited fuels available on earth.
âĸ Our demand for energy is increasing day-by-day.
âĸ It is possible that someday, most of fuels will be
exhausted , and we will have to switch to alternate
energy.
16. ENERGY CONSERVATION IN âINDIAâ
âĸ In India , government has passed â energy conservation
bill, 2001 â for better utilization of energy and conservation
of the same.
âĸ By this act, it is mandatory for energy intensive sectors to
get their âenergy audit â conducted by accredited energy
auditor.
âĸ Bureau of energy efficiency : this body keeps watch on
energy consumption patterns, develops norm for
appliances etc.
âĸ Star ratings : BEE has also initiated âstar rating systemâ
for electrical appliances e.g. - CLFâS ,
geysers,refrigerator,etc.
17. What we can do ?
âĸ Always switch off light and fans while going out of
room.
âĸ We should not open fridge frequently.
âĸ While going to purchase new products eg. Geysers,
television, CLF,etc. insist for ratings ranging from 1-5.
THREE Râs
âĸ The slogan reduce, reuse, recycle is widely used to
raise awareness against the use of non-renewable
source of energy.
âĸ Reduce consumption
âĸ Reuse manufactured products
âĸ Recycle raw materials