DEPLETION OF SOURCES OF ENERGY
We saw earlier that we cannot depend on fossil fuels for much longer. Such sources that will get depleted someday 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.
Renewable energy is available in our natural environment, in the form of some continuing or repetitive currents of energy, or is stored in such large underground reservoirs that the rate of depletion of the reservoir because of extraction of usable energy is practically negligible.
Activity 14.9:
* Debate the following two issues in class.
a) The estimated coal reserves are said to be enough to last us for another two hundred years. Do you think we need to worry about coal getting depleted in this case? Why or why not?
b) It is estimated that the Sun will last for another five billion years. Do we have to worry about solar energy getting exhausted? Why or why not?
* On the basis of the debate, decide which energy sources can be considered
(i) exhaustible,
(ii) inexhaustible,
(iii) renewable and
(iv) non-renewable.
Give your reasons for each choice.
Questions
1. Name two energy sources that you would consider to be renewable. Give reasons for your choices.
2. Give the names of two energy sources that you would consider to be exhaustible. Give reasons for your choices.
Source: This topic is taken from NCERT TEXTBOOK