Which of the following statement(s) is/are true?

1. Commercial sources of energy include firewood, agricultural waste, and dried dung.
2. More than 80% of Indian households depend on commercial sources of energy.
3. Commercial and non-commercial sources of energy together are known as conventional sources of energy.
4. Non-conventional sources of energy include solar energy, wind energy, and tidal energy.

C and D

Commercial sources are coal, petroleum, and electricity as they are bought and sold. Whereas, non-commercial sources of energy are fuelwood, agricultural waste and dried dung. These are non- commercial as they are not available in the market on a large scale.

While commercial sources of energy are generally exhaustible (with the exception of hydropower), non-commercial sources or traditional are generally renewable and nearly more than 60 per cent of Indian households depend on traditional sources of energy for meeting their regular cooking and heating needs.

Both commercial and non-commercial sources of energy are known as conventional sources of energy. There are three other sources of energy which are commonly termed as non-conventional sources — solar energy, wind energy and tidal power.