Res poly unit i (2)ppt

RENEWABLE ENERGY SOURCES
(22033)POLYTECHNIC SYLLABUS
Unit I (2/3)
FUNDAMENTALS OF ENERGY
- C.Coomarasamy
Formerly Professor, JRPC, Trichy
(2012-2013)

UNIT I (2/3)-FUNDAMENTALS OF ENERGY
 Introduction to Energy-Energy consumption and standard
of living-classification of energy resources-consumption
trend of primary energy resources
 -importance of renewable energy sources-energy chain-
common forms of energy-advantages and disadvantages of
conventional energy sources-salient features of
nonconventional energy sources-environmental aspects of
energy
 -energy for sustainable development-energy density of
various fuels-availability of resources and future trends.
 Energy scenario in India – Overall production and
consumption-Availability of primary energy resources:
 Conventional, Non-Conventional-Estimated potential and
achievement-Growth of energy sector and its planning in
India –
 Energy conservation: Meaning and importance.
2

1.8 ADVANTAGES AND DISADVANTAGES OF
CONVENTIONAL ENERGY SOURCES
Conventional energy sourcesNon-Conventional energy sources
3

Fossil fuels, nuclear and hydro resources are considered as
conventional sources.
Their use has the following advantages and disadvantages.
Advantages:
1. Cost
At present, these are cheaper than non-conventional sources.
2. Security
As storage is easy and convenient, by storing a certain
quantity, the energy availability can be ensured for certain
period.
3. Convenience
These sources are very convenient to use as technology f or
their conversion and their use is universally available.
4

Disadvantages:
1. Fossil fuels generate pollutants.
Main pollutants generated in the use of these sources are
CO, CO2, NOX, S OX, particulate matter and heat.
These pollutants
degrade the
environment, p
ose health hazards and
cause various other problems.
CO2 is mainly responsible for global warming.
2. Coal is also a valuable petro chemical and is used as
raw material for chemical, pharmaceutical and paint
industries.
From the long-term point of view, it is desirable to conserve
coal for future needs.
5

3. Safety of nuclear plants is
a controversial subject.
The major problems with nuclear energy are the following:
(a) The waste material generated in nuclear plants has
radioactivity quotients of
dangerous levels, it remains above the
safe limit for a
long period of time, and thus is a
health hazard.
Its safe disposal, which is
essential to prevent radioactive pollution, is a
challenging task.
Also, the disposed radioactive waste is required to be
guarded for a long period (till its radioactivity level comes
down to a safe limit) lest it
goes in wrong hands.
6

(b) There is possibility of accidental leakage of radioactive
material from reactor.
(c) Uranium resource, for which the technology presently
exists, has a limited availability.
(d) Sophisticated technology is required for using nuclear
resources. Only few countries posses the technology
required to use nuclear energy.
4. Hydroelectric plants are cleanest but large hydro
reservoirs cause the following problems:
(a) A large land area submerges into water leading to
deforestation
(b) Causes ecological disturbances such as earthquakes
(c) Affects wildlife
(d) Causes dislocation of a large population and their
rehabilitation.
7

1.9 SALIENT FEATURES OF
NON-CONVENTIONAL ENERGY SOURCES
Merits:
1. Non-conventional sources are available in
nature free of cost.
2. They produce no or very little pollution.
Thus, by and large, they are environment friendly.
3. They are inexhaustible.
4. They have a low gestation period.
Demerits:
1. In general, the energy is
available in dilute form from these sources.
2. Though available freely in nature, the cost of harnessing
energy from nonconventional sources is generally high.
3. Availability is uncertain; the energy flow depends on
various natural phenomena beyond human control.
4. Difficulty in transporting such forms of energy.
8

1.10 ENVIRONMENTAL ASPECTS OF ENERGY
1.10.1 Trade-off between Energy and Environment
Environment literally means surroundings.
Air, soil and water are the main constituents of environment.
However, with passage of time, their quality is continuously being
degraded due to various manmade reasons.
The chief among them are a number of activities involving
energy generation and its utilization.
During every energy conversion process, some energy is expelled by
the energy conversion system into surroundings in the form of
heat.
Also, some pollutants may be produced as a by-product of this
process.
Both of these cause degradation of environment.
Every step must be taken to conserve the environment.
Therefore, while supplying the increased energy demand, efforts
should be made to adopt measures to minimize the degradation
of environment.
The present trend is to have a trade-off between the two.
The future seems to be in favour of developing about environment
conservation. 9

1.10 ENVIRONMENTAL ASPECTS OF ENERGY
10

1.10.2 ECOLOGY:
Ecology deals with the
relationship between
living organisms (man, animal, plants and vegetation) and
the environment.
Normally, nature has
self-cleaning capability and
recycles (renews) its resources through various
processes, thus
maintaining a state of equilibrium.
The water cycle,
nitrogen cycle and
carbon cycle are the well-known examples of this.
However, when
human interference exceeds natural limits, the
ecological balance gets disturbed.
11

1.10.3 GREENHOUSE EFFECT
A greenhouse is an enclosure having transparent glass panes or
sheets as shown in Fig.
It behaves differently f or
incoming visible (short wave) radiations and
outgoing infrared (long wave) radiations.
It is transparent for
incoming solar radiation,
allows entry of sunlight and
becomes largely opaque for
reflected infrared radiation from the
earth‘s surface, thus
preventing the
exit of heat.
12

Hence, it maintains a
controlled warmer environment inside for
growth of plants in
places where the
climate is very cold.
The CO2 envelope present around the
globe in the
atmosphere behaves similar to a
glass pane and forms a big
global greenhouse.
This tends to
prevent the escape of heat from the earth, which leads to
global warming.
This phenomenon is known as
greenhouse effect.
14

Normal concentration of CO2in the atmosphere is 0.03%.
It is due to this effect that the earth
maintains an average surface temperature of 15 C that is
hospitable to life.
In the absence of this layer, the
earth would be a frozen planet at about –25 C (the
temperature of outer atmosphere).
However, any further increase in the concentration of CO 2
from the present level will upset the temperature balance .
This would cause further warming of the globe, which may
have disastrous consequences.
Apart from CO 2, other harmful gases include
methane, nitrous oxide, hydro f louro carbons, sulphur
hexafloride and water vapour.
All these gases are known as greenhouse gases.
15

THE NATURAL GREEN HOUSE EFFECT
19

1.10.4 CONSEQUENCES OF GLOBAL WARMING
Global warming is caused mainly due to the
emission of excessive CO 2 due to
burning of
fossil fuels in industry,
burning of wood and also due to
agricultural practices. (@ 0.2 degree C per decade)
This trend is
leading to the melting of
polar snowcaps, which accounts for more than
90% of the world‘s ice.
Melting of the polar snowcaps would, in turn,
increase the level of oceans and would possibly
redefine ocean boundaries
inundating low-lying areas and smaller islands.
23

1.10.4 CONSEQUENCES OF GLOBAL WARMING
During the last 100 years, the
earth‘s temperature has increased about
1/2 degree Celsius and
sea levels have risen 6 to 8 inches (15 to 20 cm).
Experts have predicted
more frequent and severe heat waves,
more intense tropical cyclones,
change in rainfall patterns,
melting of ice and glaciers at mountains,
thus causing floods, followed by
decline of water supplies and an
increased incidence of vector-borne
deceases like
malaria. 24

1.10.5 POLLUTION
Pollution is the introduction of
contaminants into the
natural environment that cause adverse change.
(a) Indoor Pollution
Indoor pollution is mainly caused due to use of
conventional chulhas (stoves) in rural areas.
Chemicals, cigarette smokes, gases, etc in urban areas.
This requires the need of improved household
stoves and minimum and safety use to
reduce indoor pollution.
(b) Outdoor Pollution
Outdoor pollution is mainly caused due to
use of fossil fuels.
Emissions from fossil fuel based plants degrade the
environment and cause various other problems.
Coal and oil are more pollutant than gas. 26

1.10.5 POLLUTION-(A) INDOOR POLLUTION
 .
27

1.10.5 POLLUTION- (A) INDOOR POLLUTION
28

1.10.5 POLLUTION- (B) OUTDOOR POLLUTION
 .
29

1.10.5 POLLUTION
Remedy:
1. Use of fossil fuels should be slowly curtailed.
2. Less-polluting technologies should be
employed for use instead of fossil fuels, i.e.,
gasified coal, which is less polluting, should be used in
power plants.
3. Clean alternative fuels such as
hydrogen should be used.
Hydrogen is the
cleanest fuel and
does not cause pollution during
power conversion.
4. Electric vehicles or
battery-operated vehicles should be
used in place of
IC-engine-based vehicles.
30

1.10.6 VARIOUS POLLUTANTS AND THEIR
HARMFUL EFFECTS
1. Particulate Matter
The presence of particulate matter
•reduces sunlight
•reduces visibility
 A level above 100µg/m 3(yearly average) results in
respiratory problems
• A level above 300µg/m 3 (yearly average) results in
bronchitis(inflammation of mucus membrane inside the
bronchial tubes, branches of the wind pipe)
 The annual average permissible limit is 75µg/m.3
31

HARMFUL EFFECTS
2. CO 2:
Carbon dioxide is ordinarily not considered a toxic gas.
But increased concentration of CO2 adversely affects the
global climate.
Excess emission of CO2 in the atmosphere causes global warming
due to greenhouse effect.
The increasing CO2 level is mainly due to large-scale combustion of
fossil
(a) fuels in coal fired thermal power plants all over the
world, and
(b) felling of trees on a large scale (deforestation) for
urbanization, agriculture, and industrialization, resulting in
reduced photosynthesis process.
32

HARMFUL EFFECTS
.
Plants survive by extracting CO2
from the air using magnesium at
the center of chlorophyll
and sunlight to convert it
into proteins and sugars
The Environmental Protection Agency formally declared carbon dioxide
and five other heat-trapping gases to be pollutants that threaten public health
and welfare, setting in motion a process that will regulate the gases blamed
for global warming. The E.P.A. said the science supporting its so-called
endangerment finding was ―compelling and overwhelming.‖
The EPA believes that concentrations of these gases are very likely
responsible for the increase in average temperatures even though
global cooling is being reported as the sun cycles down for a period of
minimum activity. 33

HARMFUL EFFECTS
3. CO:Carbon Monoxide :is a colorless, odorless gas formed when
carbon in fuel is not burned completely.
Motor vehicle exhaust contributes about 60 % of all CO emissions
nationwide (Latest Finding on National Air Quality 2002).
Other non-road engines and vehicles (such as construction
equipment and boats) contribute about 22 % of all CO emissions
nationwide.
Higher levels of CO generally occur in areas with heavy traffic
congestion.
In cities, 95 % of all CO emissions may come from motor vehicle
exhaust.
Other sources of CO emissions include industrial processes (such as
metals processing and chemical manufacturing), residential wood
burning, and natural sources such as forest fires.
Woodstoves, gas stoves, cigarette smoke, and unvented gas
and kerosene space heaters are sources of CO indoors.
34

HARMFUL EFFECTS
The highest levels of CO in the
outside air typically occur during the colder months of the year
when CO automotive emissions are greater and
nighttime inversion conditions are more frequent.
In inversion conditions
the air pollution becomes trapped near the ground beneath a
layer of warm air.
CO is formed due to incomplete burning of carbon in
inadequate air.
It seriously impairs the oxygen-dependent tissues in the
body, particularly the brain, heart and skeletal muscles.
CO concentration of
100 ppm causes
headache, 500
ppm causes collapse and
1000 ppm is fatal.
Smokers inhale CO concentrations of 400 to 450 ppm.
35

HARMFUL EFFECTS
4. Sulfur Oxides (SOx) are colorless gases formed by burning sulfur.
SOx gases are formed when fuel containing sulfur, such as coal
and oil, is burned, and when gasoline is extracted from oil
or metals are extracted from ore.
Sulfur dioxide (SO2) is the criteria pollutant that is the indicator of
sulfur oxide concentrations in the ambient air.
SO2 dissolves in water vapor to form acid, and interacts with other
gases and particles in the air to form sulfates and other products
that can be harmful to people and their environment.
Over 65% of SO2 released to the air, or more than 13 million tons per
year, comes from electric utilities, especially those that burn coal.
Other sources of SO2 are industrial facilities that derive their
products from raw materials like metallic ore, coal, and crude oil, or
that burn coal or oil to produce process heat.
Examples are petroleum refineries, cement
manufacturing, and metal processing facilities.
Also, locomotives, large ships, and some non road diesel equipment
currently burn high sulfur fuel and release SO2 emissions to the air 36

HARMFUL EFFECTS
S O x: The presence of SO 2 in the air is mainly due to manmade
reasons involving combustion of fuels containing sulphur.
The contribution from various sources is as follows:
Power plants 70%, Industry 15%, Motor vehicles 8%, Solid waste
disposal 5%, others 2%
SO 2 can further oxidize to form sulfur trioxide, which in turn
forms sulphuric acid (H 2 SO 4) when absorbed in water.
Harmful Effects
(a) Causes respiratory deceases including asthma, and the irritates
eyes and respiratory track
(b) Causes acid rains, which are harmful to
agriculture, forest ,vegetation, soil and stones (and thus to
buildings)
(c) Causes corrosion of metals, deterioration of electrical
contacts, paper, textile, building stones, etc.
The safe limit is 80 micro g/m 3 (annual average).
37

HARMFUL EFFECTS
5.Nitrogen Oxides (NOx), is the generic term used to describe the
sum of NO, NO2 and other oxides of nitrogen.
 NOx is a group of highly reactive gases that play a major role in the
formation of ozone.
 Many of the nitrogen oxides are colorless and odorless.
 However, one common pollutant, nitrogen dioxide (NO2) along
with particles in the air can often be seen as a
reddish-brown layer over many urban areas.
 Nitrogen oxides form when
fuel is burned at high temperatures, as in a combustion
process.
 The primary sources of NOx are
motor vehicles, electric utilities, and other
industrial, commercial, and residential sources that burn
fuels.
38

HARMFUL EFFECTS
Oxides of nitrogen such as
N 2O , NO, NO2,N2O3
are commonly referred as NOx
About 80% of nitrogen oxides in the
atmosphere are produced due to
natural causes (biological reactions) and
about 20% due to manmade causes—
mostly due to combustion process in
air at high temperature.
NOx is formed by the interaction of
nitrogen and
oxygen at
high temperature.
39

HARMFUL EFFECTS
Manmade causes include:
(a) Motor vehicles 7%
(b) Industry 7%
(c) Power plants 4%
(d) Solid waste 2%
Harmful Effects
(a) Causes respiratory and cardiovascular illnesses
(b) It deprives the body tissues of oxygen
(c) It also forms acid in lungs and, therefore, is more toxic
than CO
The safe limit is 100µg/m3
40

1.10.7 GREEN POWER
The term green power is used to describe sources of energy which
are considered environmental friendly, non-polluting; and
therefore may provide a remedy to the systemic effects of
certain forms of pollution and global warming.
This is, in fact, the renewable energy sourced from the sun, the
wind, water, biomass and waste.
Green energy is commonly thought of in the context of
electricity, heating, and cogeneration, and is becoming
increasingly available.
Consumers, businesses, and organizations may purchase
green energy in order to support further development, help
reduce the environmental impacts associated with
conventional electricity generation, and increase their nation’s
energy independence.
Renewable energy certificates (green certificates, or
green tags) have been one way for
consumers and businesses to support green energy.
41

1.10.8.GREEN HOUSE GAS DIAGRAM
42

1.10.8.GREENHOUSE GAS DIAGRAM KEY
 Reduce GHG emissions from farm buildings
 Reduce livestock methane emissions
 Lock up green house gases in soil and vegetation
 Reduce GHG emissions from farm machinery
 Help lock up green house gases in your land
 Reduce GHG emissions from crop production
 Produce renewable energy from your farm
*****
ENERGY IS MONERGY. LET US SAVE IT.
43

1.11 ENERGY FOR SUSTAINABLE DEVELOPMENT
Environmental degradation cannot be singled out as an
independent matter among various global issues.
Also important are the interactions among economic
development, stable energy supplies, and globe
environmental conservation.
In the next few decades fossil fuels will continue to be the
principal source of energy driving economic
development.
The source of fossil fuels is stable and their extraction is
affordable.
Attempts to restrict the use of fossil fuels for
environmental reasons are likely to have a negative
impact on economic development and the overall
availability of energy.
Thus the ‗three Es‘—environment, energy, and economic
development are closely interrelated in a complex
manner.
44

1.11 ENERGY FOR SUSTAINABLE DEVELOPMENT
The strategy for mitigating ‘three Es’ issues are a strategy for
environmentally sustainable economic development.
Herman Daly, a famous ecological economist, laid down three conditions for
sustainability:
1. The consumption rate of renewable resources is not higher
than its recovery rate.
2. The consumption rate of non-renewable resources is not
higher than the rate of increase in renewable resource supply.
3. The emission of pollutants is within the absorption capacity
of the environment.
Unfortunately, these conditions have been violated for years.
Examples of respective violations typically include deforestation, the
depletion of fossil fuels, and the increase in CO 2 concentration in the
air.
Such violations may be hard to reverse in the short term but, unless long-
term remedial action is taken, present global development trends will
not be sustainable.
In particular, a substantial reduction in resource consumption and emissions
of pollutants is essential for the development of a sustainable human
society on this planet.
45

1.12 ENERGY DENSITY OF VARIOUS FUELS:
Primary resource Energy density
Coal:
Anthracite 32–34 MJ/kg Bituminous26–30 MJ/kg Coke29 MJ/kg
Brown coal:
Lignite (old)16–24 MJ/kg Lignite (new)10–14 MJ/kg Peat8–9 MJ/kg
Crude petroleum45 MJ/kg Petrol51–52 MJ/kg Diesel45–46 MJ/kg
Natural gas50 MJ/kg, (42 MJ/m3) Methane (85% CH4)45 MJ/kg, (38 MJ/m3)
Propane50 MJ/kg, (45 MJ/m3) Hydrogen142 MJ/kg, (12 MJ/m3)
W ood10–11 MJ/kg
Natural uranium0.26–0.3 106 MJ/kg Enriched uranium2.6–3.0 106 MJ/kg
U23383 106 MJ/kg U23582 106 MJ/kg Pu23981 106 MJ/kg
Table: Energy densities/heating values of various 46

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