Biogas is obtained by using animal refuge like cow dung.

It is widely used in rural areas mainly as domestic fuel.

Efforts are being made to popularise the biogas plants in the country.

Urban and industrial waste is another source of biological energy in big cities and industrial centres.

These materials can be used for generating electricity or biogas.

The work in this direction is still in its initial stage.

Such plants have been installed in Delhi and few cities in India.