Electricity

A clean energy

very imp. for growth and prosperity (even per capita consumption is an indicator of standard of living and economic well-being)
required for - 

1. Industries
2. Household (cooking, etc.)
3. Transport
4. Agriculture
5. Education
6. Health

3 major types depending on raw material

1. Hydroelectricity
2. Thermal Electricity
3. Nuclear Electricity/ Energy