2. “It is defined as ability or capacity to do work”
We use energy to do work and make all movements. 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.
3. 1. Renewable energy-Energy that comes from naturally sources such as Sun ,
wind etc. which is inexhaustible or naturally replenished
2. Non renewable energy-Energy sources that can’t be reproduced ,generated or
replenished. Once depleted there is no more for future use.
4. • Wood –Generally used in rural area
• Coal- widely used as energy source
• Petroleum-used in auto mobiles
• Oil and Natural gas-used in lpg cylinder
Most of them are non renewable.
5. • Non sustainable
• Environmental impact
• Extraction of coal, oil and gas is dangerous and
6. Energy conservation refers to efforts made to reduce energy consumption.
Energy conservation can be achieved through increased efficient energy use,
in conjunction with decreased energy consumption or reduced consumption
from conventional energy sources.
Energy conservation act was passed in 2001 in India.
Bureau of energy efficiency (BEE)-Govt. body regulating energy efficiency.
BEE ratings for electrical appliances to indicate energy efficiency and
Trivial things like switching off the electrical appliances also
help in conserving energy.
7. • Nuclear energy
• Solar energy
• Wind energy
• Tidal energy
• Geo thermal
12. • Produced by fission or fusion of atoms.
• Fission- When the nucleus splits nuclear energy is release in the form
• Fusion- Energy is also release when atoms combine at high speed.
• Power is generated in nuclear reactor by fission.
14. • Lower carbon dioxide (and other greenhouse gases) released into the
atmosphere in power generation.
• Low operating costs (relatively).
• Large power-generating capacity able to meet industrial and city needs.
15. • Non renewable energy.
• Expensive to mine, refine and transport.
• High construction costs due to complex radiation containment systems and
• Waste (including greenhouse gasses) are generated during extraction and
• Radiation risk are high.
• Waste lasts 200 – 500 thousand years.
• Risk of terrorism.
17. o Solar energy is the energy derived from the sun through the form of solar
o Solar energy is the energy force that sustains life on the earth for all plants,
animals, and people. The earth receives this radiant energy from the sun
in the form of electromagnetic waves, which the sun continually emits
o This solar energy can be tapped directly as concentrating solar power(CSP)
(solar thermal energy)and photovoltaic(PV) cells.
18. o Solar Cell: The PV cell is the component responsible for converting light to
electricity. Some materials (e.g., silicon is the most common) produce a
photovoltaic effect, where sunlight frees electrons striking the silicon material.
The freed electrons cannot return to the positively charged sites (‘holes’) withou
flowing through an external circuit, thus generating current.
o Solar cells are designed to absorb as much light as possible and are
interconnected in series and parallel electrical connections to produce
desired voltages and currents.
o PV is best suited for remote site applications that have small to moderate powe
requirements, or small power consuming applications even where the grid is in
20. • Solar cells are long lasting sources of energy which can be
used almost anywhere.
• Solar cells are totally silent and non-polluting.
• Solar cells provide cost effective solutions to energy issues in
places where there is no mains electricity.
• As they have no moving parts, they require little or no
maintenance at all, and have a long lifetime.
• Solar cells can easily be installed on roofs, which means no
new space is needed and each user can quietly generate their
21. • The initial cost is quite high.
• Most types of solar cells require large areas of land to
achieve average efficiency.
• Air pollution and weather can also have a large effect on the
efficiency of the cells.
• The silicon used in cells is also very expensive.
31. Hydropower is power that is derived from the force or energy of
moving water, which may be harnessed for useful purposes. Prior to
the development of electric power, hydropower was used
for irrigation, and operation of various machines, such as
watermills, textile machines, sawmills, dock cranes, and
33. Hydropower available = ρQH
Where ρ-density of water, g-acceleration due to gravity,
Q-discharge of water, H-head
34. • Hydropower is clean. It does not emit any of the waste gases that contribute
to air pollution, acid rain, and global warming.
• No fuel is required.
• Hydropower is reliable. As long as there is water, there will be an energy
• Hydropower is extremely efficient.
35. o Hydropower dams disrupt the natural flow of rivers.
o A large area for reservoir construction.
o Building a dam on a river has major implications for the biota
found in the river system.
o If dam breaks it would be a disaster causing heavy floods
affecting nearby habitat.
37. • During high tide, water flows from sea to bay.
• Turbine produces power.
• During low tide, water flows from bay to sea.
• Another set of turbine produces power.
• Common turbines can also be used.
•Power generated similar to hydropower.
39. o Utilization of organic waste to produce
o Chemical energy stored in plants and
animals or in the animal waste is called
o Burning of the biomass will release the
energy in the form of heat
o Can also be converted into other energy
source such as bio-fuel
41. o On the contrary, biomass crops are seen as occupying agricultural land.
o Could contribute to global warming and particulate pollution if directly
43. The energy is derived from biological carbon fixation, Biofuels
include a wide range of fuels which are derived from biomass.
There are two types of bio-fuel-
(i)First generation bio-fuels
a. Bio-alcohols(fermentation of sugar)
b. Bio-diesel (transesterification of oils or fats)
c. Green diesel (fractional distillation of oil)
d. Bio-ethers(dehydration of alcohol made from organic material)
e. Bio-gas(anaerobic digestion of organic material)
44. (ii) Second generation bio-fuel
Many second generation biofuels are under development such
as Cellulosic ethanol, Algae fuel.
Gaseous biofuels include biogas, landfill gas and synthetic gas.
45. It is eco friendly.
The biofuels are much safer to handle and the health effects are also much
lesser as compared to fossil fuels.
The biofuels can help to reduce the global warming
46. Biofuels have a lower energy output than traditional fuels and therefore
require greater quantities to be consumed in order to produce the same
Lots of cost required to produce biofuels on technological processes.
There might be bad smell which is the outcome of the biofuel production
48. Natural heat extracted from the
For electricity, steam is formed using
the heat which rotates the turbine
fitted to generator and at last,
electricity is generated.
49. Geothermal energy generally involves low running costs since it
saves 80% costs over fossil fuels and no fuel is used to generate
Being the renewable source of energy , geothermal energy has
helped in reducing global warming and pollution.
Geothermal systems does not create much pollution as it releases
some gases from deep within the earth which are not very harmful
to the environment.
50. To get geothermal energy, requires installation of power plants, to
get steam from deep within the earth and this require huge one
electricity towers, stations need to set up to move the power from
geothermal plant to consumer.
It is only suitable for regions where temperature below the earth
are quite high and can produce steam over a long period of time.
51. Bagasse is the fibrous matter that remains after sugarcane or sorghum stalks are
crushed to extract their juice
52. • It is currently used as a biofuel and in the manufacture of pulp and
• It can also be used for making boards resembles like Plywood or
• Low cost
Dusts from the processing of bagasse can cause the chronic lung
condition pulmonary fibrosis
53. • Biofuels ,bagasse,
etc. are low power
• Hydro power is the
cheapest compared to
all other energy sources
54. • To make sure we have plenty of energy in the future, it's up to all of us
to use energy wisely.
• We must all conserve energy and use it efficiently. It's also up to those
who will create the new energy technologies in the future.