Energy Resources

Energy Resources

Intended
Learning Outcomes

At the end of this session, students will be able to

• Explain Energy Resources

• Discuss increasing energy needs

• Describe the renewable/ non renewable

• Explain the use of alternate energy sources

Contents

• Energy Resources

• Increasing energy needs

• Renewable/ non renewable

• Use of Alternate energy sources

Energy
Resources

• Energy is defined by physicists as the capacity to do work

• Sun is the primary energy source in our lives, we use it
directly for its warmth and through various natural processes that provide us
with food, water, fuel and shelter

• Sun’s rays power the growth of plants, which form our food
material, give off  oxygen  which 
we  breathe  in 
and  take  up 
carbon  dioxide  that 
we breathe out

• Energy from the sun evaporates water from oceans, rivers
and lakes, to form clouds that turn into rain

• Today’s fossil fuels were once the forests that grew in
prehistoric times due to the energy of the sun

• In  India,  manual 
labour  is  still 
extensively  used  to 
get  work  done 
in agricultural systems and domestic animals used to pull carts and
ploughs

• Electrical energy produced in several ways, powers
transport, artificial lighting, agriculture and industry

• Nuclear energy is held in the nucleus of an atom and is
now harnessed to develop electrical energy

• We use energy for household use, agriculture, production
of industrial goods and for running transport

• Modern agriculture uses chemical fertilizers, which
require large amounts of energy during their manufacture

• Industry uses energy to power manufacturing units and the
urban complexes that support it

• Energy-demanding roads and railway lines are built to
transport products from place to place and to reach raw materials in mines and
forests

• No energy related technology is completely ‘risk free’ and
unlimited demands on energy increase this risk factor many fold

• All energy use creates heat and contributes to atmospheric
temperature

• Many forms of energy release carbon dioxide and lead to
global warming

• Nuclear energy plants have caused enormous losses to the
environment due to the leakage of nuclear material

• The inability to effectively manage and safely dispose of
nuclear waste is a serious global concern

• At present almost 2 billion people worldwide have no
access to electricity at all

  While  more 
people  will  require 
electrical  energy,  those 
who  do  have

• In addition, a large proportion of energy from electricity
is wasted during transmission as well as at the user level

• It is estimated that the currently used methods of using
renewable energy and non-renewable fossil fuel sources together will be
insufficient to meet foreseeable global demands for power generation beyond the
next 50 to 100 years

• Thus  when  we 
use  energy  wastefully, 
we  are  contributing 
to  a  major environmental disaster for our earth

• We all need to become responsible energy users

  An  electrical 
light  that  is 
burning  unnecessarily  is 
a  contributor  to

Types of
energy

• There are three main types of energy; those classified as
Non-renewable; Renewable

Non-renewable
energy

• To produce electricity from non-renewable resources the
material must be ignited

• The fuel is placed in a well contained area and set on
fire

• The heat generated turns water to steam, which moves
through pipes, to turn the blades of a turbine

• This converts magnetism into electricity, which we use in
various appliances

• Non-Renewable Energy Sources:  These consist of the mineral based hydrocarbon
fuels coal, oil and natural gas, etc.

• These are called ‘fossil fuels’ because they are formed
after plant life is fossilized

• At the present rate of extraction there is enough coal for
a long time to come

• Oil and gas resources however are likely to be used up
within the next 50 years

• When these fuels are burnt, they produce waste products
that are released into the atmosphere as gases such as carbon dioxide, oxides
of sulphur, nitrogen, and carbon monoxide, all causes of air pollution

• These have led to health problems in an enormous number of
people all over the world and have also affected buildings like the Taj Mahal
and killed many forests and lakes due to acid rain

• Warming the seas also leads to the death of sensitive
organisms such as coral

Oil and its
environmental impacts

• India’s oil reserves which are being used at present lie
off the coast of Mumbai and in Assam

• Most of our natural gas is linked to oil and because there
is no distribution system, it is just burnt off, this wastes nearly 40% of
available gas

• The processes of oil and natural gas drilling, processing,
transport and utilisation have serious environmental consequences, such as
leaks in which air and water are polluted and accidental fires that may go on
burning for days or weeks before the fire can be controlled

Coal and
its environmental impacts

• Coal is the world’s single largest contributor of
greenhouse gases and is one of the most important causes of global warming

• Many coal-based power generation plants are not fitted
with devices such as electrostatic precipitators to reduce emissions of
suspended particulate matter (SPM) which is a major contributor to air
pollution

• Thermal power stations that use coal produce waste in the
form of ‘fly ash’

• Large dumps are required to dispose off this waste
material, while efforts have been made to use it for making bricks

• The transport of large quantities of fly ash and its
eventual dumping are costs that have to be included in calculating the
cost-benefits of thermal power

Renewable
energy

• Renewable energy systems use resources that are constantly
replaced and are usually less polluting

• Examples include hydropower, solar, wind and geothermal
(energy from the heat inside the earth)

• We also get renewable energy from burning trees and even
garbage as fuel and processing other plants into biofuels

• One day, all our homes may get their energy from the sun
or the wind

• Your car’s gas tank will use biofuel

• Your garbage might contribute to your city’s energy supply

• Renewable energy technologies will improve the efficiency
and cost of energy systems

Hydroelectric
Power

• This  uses  water 
flowing  down  a 
natural  gradient  to 
turn  turbines  to generate electricity known as
‘hydroelectric power’ by constructing dams across rivers

• Between 1950 and 1970, Hydropower generation worldwide
increased seven times

Drawbacks

• Although hydroelectric power has led to economic progress
around the world, it has created serious ecological problems

• To produce hydroelectric power, large areas of forest and
agricultural lands are submerged.

• Silting of the reservoirs (especially as a result of
deforestation) reduces the life of the hydroelectric power installations

• Water is required for many other purposes besides power
generation.

• The use of rivers for navigation and fisheries becomes
difficult once the water is dammed for generation of electricity

• Resettlement of displaced persons is a problem for which
there is no ready solution.

• In certain regions large dams can induce seismic activity
which will result in earthquakes. There is a great possibility of this
occurring around the Tehri dam in the Himalayan foothills. Shri Sunderlal
Bahuguna, the initiator of the Chipko Movement has fought against the Tehri Dam
for several years

Solar
energy

 Energy Resources

• In one hour, the sun pours as much energy onto the earth
as we use in a whole year

• Today we have developed several methods of collecting this
energy for heating water and generating electricity

• Solar heating for
homes:
Modern housing that uses air conditioning and/ or heating are
extremely energy dependant

• A passive solar home or building is designed to collect
the sun’s heat through large, south-facing glass windows

• In solar heated buildings, sunspaces are built on the
south side of the structure which act as large heat absorbers

• The floors of sunspaces are usually made of tiles or
bricks that absorb heat throughout the day, then release heat at night when it’s
cold

• Solar water
heating:
Most solar water-heating systems have two main parts: the solar
collector and the storage tank

• The solar energy collector heats the water, which then
flows to a well-insulated storage tank

  Solar  water-heating 
systems  cannot  heat  water 
when  the  sun 
is  not shining. Thus homes must
also have a conventional backup system

• Solar cookers:
The heat produced by the sun can be directly used for cooking using solar
cookers

• A solar cooker is a metal box which is black on the inside
to absorb and retain heat

• The lid has a reflective surface to reflect the heat from
the sun into the box

• The box contains black vessels in which the food to be
cooked is placed

• Other Solar-Powered
Devices:
Solar desalination systems (for converting saline or brackish
water into pure distilled water) have been developed

• Photovoltaic
energy:
The solar technology which has the greatest potential for use
throughout the world is that of solar photo voltaic cells which directly
produce electricity from sunlight using photovoltaic (PV) (also called solar)
cells

• Solar thermal
electric power:
   Solar   radiation  
can   produce   high temperatures, which can generate
electricity. Areas with low cloud levels of cover with little scattered radiation
as in the desert are considered most suitable sites

• Solar thermal systems change sunlight into electricity, by
focusing sunlight to boil water to make steam

• Biomass energy:
When a log is burned we are using biomass energy

• Biomass energy is a form of stored solar energy

• Although  wood  is 
the  largest  source 
of  biomass  energy, 
we  also  use agricultural waste, sugarcane wastes and
other farm by-products to make energy

• Ways to use biomass;

• It can be burned to produce heat and electricity

• Changed to a gas-like fuel such as methane or changed to a
liquid fuel.

Liquid fuels, also called biofuels, include two forms of
alcohol: ethanol and Methanol

• Biomass can be changed directly into liquid fuel, it could
someday supply much of our transportation fuel needs for cars, trucks, buses,
airplanes and trains with diesel fuel replaced by ‘biodiesel’ made from
vegetable oils

• Organic municipal solid waste includes paper, food wastes
and other organic non-fossil-fuel derived materials such as textiles, natural
rubber, and leather can be converted into electricity by combustion boilers or
steam turbines

• Biogas: Biogas
is produced from plant material and animal waste, garbage, waste from
households and some types of industrial wastes, such as fish processing,
dairies and sewage treatment plants

• It is a mixture of gases which includes methane, carbon
dioxide, hydrogen, sulphide and water vapour

• Once used the residue is used as an agricultural
fertilizer

• Biogas plants have become increasingly popular in India in
the rural sector

• The biogas plants use cow-dung, which is converted into a
gas which is used as a fuel

• National Project on Biogas Development (NPBD) and
Community / Institutional Biogas Plant Program promote various biogas projects

Energy
Resources

• Wind Power:
Wind was the earliest energy source used for transportation by sailing ships

• Some 2000 years ago, windmills were developed in China,
Afghanistan and Persia to draw water for irrigation and grinding grain

• In Tamil Nadu, there are large wind farms producing 850
megawatts of electricity

• At present, India is the third largest wind energy
producer in the world

• Power in wind is a function of the wind speed and
therefore the average wind speed of an area is an important determinant of
economically

• Over the past two decades, a great deal of technical
progress has been made in the design, siting, installation, operation and
maintenance of power-producing wind mills (turbines)

• These improvements have led to higher wind conversion
efficiencies and lower electricity production costs

• Geothermal energy: is the energy stored within the earth
(“geo” for earth and “thermal” for heat)

• Geothermal energy starts with hot, molten rock (called
magma) deep inside the earth which surfaces at some parts of the earth’s crust

• The heat rising from the magma warms underground pools of
water

• If there is an opening, hot underground water comes to the
surface and forms hot springs, or it may boil to form geysers

• With modern technology, wells are drilled deep below the
surface of the earth to tap into geothermal reservoirs, known as direct use of
geothermal energy and it provides a steady stream of hot water that is pumped
to the earth’s surface

• Geothermal energy is nearly as cheap as hydropower and
will thus be increasingly utilised in future

Nuclear
Power

• In 1938 two German scientists Otto Hahn and Fritz Strass
man demonstrated nuclear fission

• They found they could split the nucleus of a uranium atom
by bombarding it with neutrons

• As the nucleus split, some mass was converted to energy

• Nuclear power industry however was born in the late 1950s

• First large-scale nuclear power plant in the world became
operational in 1957 in Pennsylvania, US

• Dr. Homi Bhabha was the father of Nuclear Power
development in India

• The Bhabha Atomic Research Center in Mumbai studies and
develops modern nuclear technology

• India has 10 nuclear reactors at 5 nuclear power stations
that produce 2% of India’s electricity

• These are located in Maharashtra (Tarapur), Rajasthan,
Tamil Nadu, Uttar Pradesh and Gujrat

• The nuclear reactors use Uranium 235 to produce electricity

• Energy released from 1kg of Uranium 235 is equivalent to
that produced by burning 3,000 tons of coal

• Heat energy produced in the reaction is used to heat water
and produce steam, which drives turbines that produce electricity

• The drawback is that the rods need to be changed
periodically, this has impacts on the environment due to disposal of nuclear
waste cause to aquatic ecosystems, even though it is cooled by a water system
before it is released

• Land, water, vegetation are destroyed for long periods of
time

• Management, storage and disposal of radioactive wastes
resulting from nuclear power generation are the biggest expenses of the nuclear
power industry

Summary

• Energy is defined by physicists as the capacity to do work

• Energy has always been closely linked to man’s economic
growth and development

• 3 main types of energy; Non-renewable, Renewable and
Nuclear energy

• Coal is the world’s single largest contributor of
green-house gases and is one of the most important causes of global warming

• Energy released from 1kg of Uranium 235 is equivalent to
that produced by burning 3,000 tons of coal

 

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