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DU Question Bank
Science and Life
Energy
What are the different sources of energy? Which one of them in
your view holds the
maximum prospect for common use in the future, and why?
1. At present the sources of energy in common use globally are
the fossil fuels: coal,petroleum products and natural gas.
2. Different petroleum fractions such as gasoline, diesel and
aviation fuel are the majorfuels for transport.
3. Electricity generation worldwide relies most on coal and to
some extent natural gas.4. Natural gas and liquefied petroleum gas
are also used as cooking fuel in addition to
kerosene and coal still used, especially in low income
households of developing
countries.5. The abovementioned fuels are non-renewable, they
cause air pollution and contribute
to global warming hence it would be good to reduce dependence on
them.
6. Another other energy source used for electricity generation
to a limited extent isnuclear energy in the form of thermal power
plants based on nuclear fission reactors
at present.
7. Since nuclear fuel (largely fissionable Uranium 235) is
limited, this type of nuclearenergy is also non-renewable though it
does not contribute to global warming.
8. In addition, fission reactors produce hazardous nuclear
waste, safe disposal of whichis a difficult task.
9. Nuclear energy in the form of fast breeder reactor, which
produces more nuclear fuelthan it consumes, and controlled nuclear
fusion reaction, if harnessed, can beconsidered renewable. However,
hazardous nuclear waste would still be produced.
10.Renewable energy sources used at present are: hydropower,
solar energy, energy frombiomass and wind energy to a greater
extent and geothermal energy and tidal energy
to a limited extent (they are highly site-specific).
11.Rather than relying on a single energy source for sustainable
development, acombination of renewable energy sources with limited
and progressively diminishing
use of fossil fuels would be a better policy globally as well as
for developing
countries like India.
12.Solar energy is available all over the world and especially
in the tropics (e.g. in India),where the sun shines strongly
throughout the year.
13.India and other developing countries can concentrate on
researching solar energy tobring down its cost and increase its
productivity for electricity generation since the
chief obstacle in wider use of solar energy for electricity
generation is the cost of solar
photovoltaic films and the low productivity of solar power
plants.
14.In addition, India can also focus on clean biomass energy
such as gobar gas plants andenergy from biodegradable municipal and
agricultural waste where possible.
15.Wind energy can be utilised in coastal areas, desert areas
and hilly regions with highwind speeds.
16.Hydropower is a clean and green option with smaller dams to
reduce the area offlooding and displacement of population.
17.A series of small dams can be built after cost-benefit
analysis and agreement of localpopulation affected by the dams.
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18.Efforts can be made to identify tidal basins on the coast
where it would beeconomically viable to construct a tidal power
plant.
19.Similarly, geothermal energy can be harnessed to a greater
extent in regions where itis known or suspected to be
accessible.
20.Energy policy can emphasise on localised development of
energy resources so that acombination of energy sources can be
exploited keeping local conditions in mind.
21.India can also contribute to the ongoing global efforts to
harness the power ofhydrogen from water (an inexhaustible source,
since the product of combustion of
hydrogen is water) and controlled nuclear fusion, which might go
a long way in
permanently meeting the worlds energy needs.
Give an estimate of the energy needs in a typical Indian home.
Give your description of
the home and suggest ways to avoid wastage.
1. Energy needs of Indian homes vary according to family size,
size of dwelling andeconomic status.
2. Energy needs are also dependent on the season of the year
since fans and airconditioners increase the electricity consumption
in summer.
3. Energy needs of a family would also depend on whether all the
family members areworking. In such households no electricity would
be consumed during weekdays
when all occupants of the house are away.
4. A typical Indian middle class working couple with 1 or 2
children residing in a 2/3bedroom house may require 200 to 400
units of electricity (in the form of Kilowatt
hour, Kwh).
5. Peak summer consumption is around 400 units while consumption
during the rest ofthe year is around 200 units.
6. Most cities have a system of electricity billing where the
first slab costs less, withprogressive increase above that. For
example, in Delhi, domestic power consumers
pay Rs.3.90 per unit for the first 200 units. Each unit consumed
between 201 and 400
units costs Rs.5.80 per unit and between 401 and 800 units costs
Rs.6.80 per unit. Any
consumption above 800 units costs Rs.7 per unit.
7. Thus electricity bill for the same family may from Rs. 1000
to Rs. 4000, depending onthe season and other factors like
vacations, visitors, house guests etc.
8. For cooking, a household described above may consume 10-15
cubic metres ofcooking gas (costing Rs 200300).
9. Cooking gas consumption per month is also dependent on
holidays, house guests,guests invited for meals, festivals etc.
10.A typical apartment in Delhi may consist of a drawing room,
dining space (or drawingcum dining room), two or three bedrooms, a
kitchen and one or two bathrooms.
11.In addition, there may be a balcony and a terrace or two
balconies.12.Most people have their TV in the drawing or drawing
cum dining room. Some
families may have an additional TV in one of the bedrooms.
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13.There are also 1-2 fans and lights in the drawing cum dining
room and 1 fan and 1light in each of the bedrooms.
14.The kitchen, bathroom(s) and balcony have lights too.15.There
may also be air conditioners in each of the bedrooms and also in
the drawing
room.16.Other electrical appliances may include refrigerator,
food processor, electric toaster,
electric oven, hot water geyser in bathroom and kitchen, music
system, electric iron,
computer, room heaters for winter, water purifier, vacuum
cleaner, washing machine,
kitchen chimney, microwave oven etc.
17.Electricity wastage may be avoided by making sure that rooms
without occupantshave all lights and fans switched off; appliances
are not left in Standby mode for long
periods; energy efficient appliances (as per Bureau of Energy
Efficiency star ratings)
are purchased; hot water geysers and air conditioners are used
strictly when required;
washing machines are used only with full load etc.18.Cooking
fuel wastage may be avoided by cooking in covered vessels; using
pressure
cooker when possible; cutting vegetables smaller so that they
cook faster; using
medium or low flame most of the time; turning off the gas flame
as soon as cooking is
over etc.
19.Energy usage in any family may be different depending on the
familys needs andtraditions.
20.Energy conservation methods have to be accordingly adapted as
well keeping thefamilys situation in mind. All members of the
family need to agree and cooperate in
the energy conservation processes.
