1) they are energy efficient. 2)they have high calorific value.
3)easy to store.
4)easy to use.
7) easy to handle.
1)some are not eco friendly.
2) cause pollution (petrol diesel etc.)
3)not energy efficient like tidal energy powerplant
4)cant be set up anywhere eg... dams thermal powerplants windmills etc.5)
6)maintenance is very tough like dam tubines etc.
7)release harmful gases if not properly used like peteol etc.