"Non-Conventional" sources of energy include which of the following options?

1. Solar energy
2. Electricity
3. Firewood
4. Tidal power
5. Dried dung

A and D only

The correct answer is Option 3: A and D only

Both commercial and non-commercial sources of energy are known as conventional sources of energy. Commercial sources are coal, petroleum and electricity as they are bought and sold. 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.

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