Chapter 11
CHAPTER NO.11 ENERGY CONSUMPTION
Energy is the capacity to do work, It is the basis
of human life. No activity in this universe is possible without the use or
transformation of energy. Human society depends on energy for its varied
activities. Also, the energy requirements of the
society have been changing fast with passage of time.
Sources of energy and modes of its production have
also been changing since the early man. As the civilization grew, energy became
associated with quality of life and economic development.
CHANGING GLOBAL PATTERNS OF ENERGY
CONSUMPTION
The early man was a hunter, a gatherer. His
activities included food gathering, chasing and killing wild animals, The
energy from food gave him the much needed physical or muscular strength for
these activities. In other words, we can say that he
obtained his entire energy directly from the food-chains. He was not aware of
any other forms of energy and his demand of energy was very low. The
photosynthetic activity of the green plants has been the primary source of
energy for all types of food chains, since the origin of early life forms. With
the discovery of fire, the early human beings made use of wood as a source of
energy. They used fire for cooking meat, protection against wild animals and
keeping themselves warm. As they learnt about the use of tools, they started
practicing agriculture
along the river banks. The domestication of animals
helped in hamessing their muscular energy for agricultural tasks. As the
civilization progressed further, the metal tools, besides discovery of wheel
enhanced the working efficiency of human beings, The wheel and use of animals
led to development of the cart. This facilitated transportation of things from
one place to other. The animals such as ox,horse, donkey, bull etc. were used
for carrying heavy loads, to do agricultural work and as means of
transportation. Till 17th century, man used
muscular, animal, wood, wind and water energy for carry-ing out different
activities. The firewood obtained from forests was the major source of energy
until the middle of nineteenth century. It alone accounted for about 50 percent
of the world’s total energy
consumption around 1850. In rural India, firewood
and agricultural waste are still used as an impor-tant source of energy. With
further growth of civilization, the human activities became more diversi-fied.
The invention of steam engine played a key role in industrial revolution around
the middle of nineteenth century. This resulted in setting up of large number
of industries in Europe and America. In order to fulfill increasing energy
demands, the use of firewood was replaced by discovery of coal, cil and natural
gas. During the first decade of 20th century, coal accounted for 75 percent of
the total energy consumption in houses, industries and transportation. The 20th
century witnessed a great increase in the use of petroleum fuels like oil and
natural gas. These petroleum products provided about 82 percent of the total
global commercial energy consumption by 1984. The excessive use of these fossil
fuels (coal, oil, natural gas) led to contamination of the environment. It was
also realized that the fossil fuels are exhaustible resources and are not
unlimited in nature. Their supply may come to an end in the near future. In
fact, it took millions of years in nature for formation of these fossil
fuels by slow decomposition of tree, algae and small
marine organisms.
In modem society, the consumption of energy is
increasing very rapidly with the growing popu-lation, A major part of energy
being consumed is used by industries associated with production of
chemicals, minerals, food and other products. The
transportation by automobiles and extensive agri-
culture involving heavy machinery also consume a
great amount of energy. For domestic purposes,energy is used for cooking food,
lighting, warming or cooling houses and running several home
appliances. In view of exhaustible nature of fossil
fuels, the renewable sources of energy such as hydropower or hydel energy, wind
energy, solar energy, geothermal energy and biomass energy are
also being exploited, Attempts are being made to
develop more efficient technology for harnessing energy from these renewable
sources.
The consumption of energy is not uniform in
different parts of the world. Energy consumption rate is very high in developed
countries like the United States of America (USA), Canada, Switzer-land, Norway
etc. According to an estimate, 22.60 percent of the global population that
lives in developed countries accounts for 74 percent of the total energy
consumption world over. The non-renewable sources (coal, oil, natural gas,
nuclear energy) provide 90 percent of the total energy
consumed in developed countries. Renewable sources
such as hydropower, geothermal, biomass and solar energy account for the
remaining 10 percent energy. On the other hand, in the developing countries
like India and China, renewable and non-renewable sources provide 41 percent
and 59
percent of the total energy consumption
respectively, It indicates that less developed countries are obtaining a
substantial amount of energy from their renewable sources, especially the
biomass. In view of exhaustible nature of fossil fuels and the resulting
environmental concerns, efforts are also
being made to produce cost-effective alternative
fuels such as methanol, ethanol, fuel cells etc, These
sources relatively cause less pollution of the
environment.
ENERGY CONSUMPTION AS A MEASURE OF
QUALITY OF LIFE
The input in terms of energy consumption is directly
linked with economic growth of a country in different sectors. It is a measure
of richness or quality of life of the people of a nation or society.
There exists a direct correlation between per capita
income and per capita energy consumption. The higher consumption of energy
indicates higher quality of life. The rich may afford to buy a car and make use
of the fuel but the poor may not be able to buy a bicycle. There is great
difference in per capita energy consumption between developed countries and
developing countries. In developed countries, each person consumes nine times
more energy than used by an average person in devel-
Owing to higher per capita energy consumption, 22.6
percent of the total global population living in developed countries consumes 74
percent of the total energy consumed world over. The per capita energy
consumption in India is much lower than developed countries like the USA and
Japan.The average daily use of energy by an American is 25 times more than used
by an Indian. In 1984,
the United States of America with about 5 percent of
the global population accounted for 25 percent of the world's total commercial
energy consumption. On the other hand, India with 15 percent of the world's
population used only 1.5 percent of the world’s commercial energy Higher energy
consumnp-tion rate of developed countries indicates higher quality of life of
people.
(Per capita income and per capita energy consumption
of selected countries in 1997)
(Source : The world development report 2000-2001)
The consumption of energy by a country depends upon
many factors. These include the type of economy, climatic conditions, cost
factor and availability of energy, state of economic development
etc. The countries with industrial economy consume
more energy than countries with agricultural
economy. In countries with cold climatic conditions,
a large amount of energy is used in heating buildings. The lower prices and
easy availability of energy sources also result in higher consumption trate,
Energy consumption in rural societies is lower in comparison with the urban
societies. This
difference is also reflected in standard of living.
In India, 70 percent of population lives in villages and
use about 40 percent of the total energy. More than
40 percent of the Indian population depend upon non-commercial sources of
energy (fire wood, crop residues, animal waste etc.) and do not have the
capacity to buy commercial sources of energy (ail, coal, natural gas,
hydro-electricity etc.)
RISING DEMAND FOR ENERGY
The global demand of energy has been increasing
every day since the dawn of industrial revo-lution. Most of this increase has
taken place in today’s more developed countries. The per capita
energy consumption in these countries may have
reached at or near saturation now. The population of these countries has become
more stable. They need a greater amount of energy to maintain theircurrent
state of economic growth and standard of living. But in contrast to developed
countries, the population in the developing countries is increasing at a high
rate and most of the current increase in global energy consumption is occurring
in these countries. One of the major goals of the developing countries is to
improve the quality of life of their citizens. This objective is associated with
rapid
economic development in different sectors that
require heavy inputs in terms of energy. This has led
to an enormous demand of energy for different types
of industry (metal, chemical, glass, paper,cement, fertilizer, food etc.),
transportation means (highway vehicles, rail engines, ships, aeroplanes etc.)},
agzicultural machinery and domestic services.
Most of the energy required for these activities is
being harnessed from the fossil fuels including coal, oil and natural gas.
About 82 percent of the world's commercial energy is being supplied by these
non-renewable energy sources. In the developed countries, these fossil fuels
account for about
85 percent of the total energy consumption. In this
concem, the developing countries make a sub-stantial use of their
non-commercial energy sources (fire wood, crop residues, animal waste etc.) and
use fossil fuels for about 58 percent of their total energy consumption.
The fossil fuels are not unlimited and may vastly
decrease in the near future, The excessive use of these substances has also
resulted in large scale pollution of the environment. Half of the world
population uses firewood as a major source of energy. But the rapid
deforestation is leading to shortage of firewood supply. The rising demand of energy
and need to reduce emission of pollutants,have necessitated exploration of some
suitable altemative sources of energy. India is a developing
country and its demand for energy is increasing
rapidly duc to industrialization,
transportation, mecha-nization of agriculture, urbanization, domestic use and
other developmental activities, Out of the total energy consumed in the
country, 50 percent is utilized by industry, 22 percent for transportation, 12
percent for domestic use and 8 percent for agriculture.
The rural people use about 40 percent of the total energy of the country.
Non-commercial sources such as fire wood, animal waste and crop
residues account for about 80 percent of their
energy demand.
Although, the per capita energy consumption in India
is quite low but still there exists a shortage
of energy supply. The gap between demand and supply
is widening day by day. People have to encounter shortage of petrol, kerosene,
diesel, cooking gas, electricity and firewood.
Our forests are not sufficient enough to provide
required amount of firewood on sustainable basis. The consumption of different
petroleum products in industry and transportation is increasing at
a high rate. The crude ail production in the country
falls short of its rising demand. More than half of the total requirement of
petroleum products (petrol, diesel, kerosene etc.) is imported from other
countries, In view of present requitement and future demand, the natural gas
reserves are also very limited in quantity. Efforts are being made to locate
more gas reserves. In spite of an increase in the
installed capacity of electricity generation every
year, the electricity demand is much higher than this
installed capacity. The demand of energy in
different sectors is increasing each day but the energy sources of the country
are insufficient to meet this demand generated by rapid growth of population
and economic development.
EXERCISE
(A) Very short answer type questions (1
mark each) :
1, Whatis energy?
2, What were the activities of early man ?
3. Whatis the primary source of energy ?
4. When did early man start the use of wood as a
source of energy 7
5. Name two important sources of energy in rural
India ?
6. How were the fossil fuels formed in nature ?
7. Give two non-conventional sources of energy.
8. Whatis the major source of energy for different
sectors ?
9, Which factor is responsible for shortage of
firewood ?
(B) Short answer type questions (2
marks each) :
1. How did carly man obtain energy ?
2, How did the discovery of wheel enhance the
working efficiency of man ?
3. Why more emphasis is being given to exploit
renewable sources of energy 7
4. Name two altemate fuels.
5. What is the reason for higher consumption of
energy in developed countries ?
6. What are two limitations of fossil fuels as a
source of energy ?
(C) Short answer type questions (4
marks each):
1, Write a short note on consumption of fossil
fuels.
2. What are different energy consuming activities of
the modem society ?
3. Explain different factors that determine energy
consumption by a county.
4. Write about energy conusmption by rural people in
India.
5. Explain the demand and supply of petroleum
products in India.
(D) Long answer type questions: (5
marks each):
1. Discuss the consumption of energy sources from
ancient to modern times.
2. White about consumption of energy in developed
and developing countries.
3. Comment upon the statement “Energy consumption is
a measure of quality of life.”
4. Discuss energy consumption pattem and problems in
India.
