Page 12 - Sources of Energy

Q U E S T I O N S

1. What kind of mirror – concave, convex or plain – would be best suited
for use in a solar cooker? Why?
2. What are the limitations of the energy that can be obtained from the ?
oceans?
3. What is geothermal energy?
4. What are the advantages of nuclear energy?

14.4 ENVIRONMENTAL CONSEQUENCES
14.4 ENVIRONMENT
14.4 ENVIRONMENTAL CONSEQUENCESAL CONSEQUENCES
14.4 ENVIRONMENT
14.4 ENVIRONMENTAL CONSEQUENCESAL CONSEQUENCES
We have studied various sources of energy in the previous sections.
Exploiting any source of energy disturbs the environment in some way
or the other. In any given situation, the source we would choose depends
on factors such as the ease of extracting energy from that source, the
economics of extracting energy from the source, the efficiency of the
technology available and the environmental damage that will be caused
by using that source. Though we talk of ‘clean’ fuels like CNG, it would
be more exact to say that a particular source is cleaner than the other.
We have already seen that burning fossil fuels causes air pollution. In
some cases, the actual operation of a device like the solar cell may be
pollution-free, but the assembly of the device would have caused some
environmental damage. Research continues in these areas to produce
longer lasting devices that will cause less damage throughout their life.
Activity 14.8
Activity 14.8
Activity 14.8
Activity 14.8
Activity 14.8
 Gather information about various energy sources and how each
one affects the environment.
 Debate the merits and demerits of each source and select the
best source of energy on this basis.

Q U E S T I O N S
?
1. Can any source of energy be pollution-free? Why or why not?
2. Hydrogen has been used as a rocket fuel. Would you consider it a cleaner
fuel than CNG? Why or why not?

14.5 HOW L
14.5 HOW L
14.5 HOW LONG WILL AN ENERGY SOURCE LONG WILL AN ENERGY SOURCE LAST US?AST US?
14.5 HOW LONG WILL AN ENERGY SOURCE LAST US?
14.5 HOW LONG WILL AN ENERGY SOURCE LONG WILL AN ENERGY SOURCE LAST US?AST US?
We saw earlier that we cannot depend on the fossil fuels for much longer.
Such sources that will get depleted some day are said to be exhaustible
sources or non-renewable sources of energy. On the other hand, if we
manage bio-mass by replacing the trees we cut down for fire-wood, we
can be assured of a constant supply of energy at a particular rate. Such
energy sources that can be regenerated are called renewable sources of
energy.

Sources of Energy 253