The main ideas:
1- Forms of renewable energy sources such as: sun, wind and biomass.
2- The uses of each form of renewable energy sources.
3- The advantages of each form of renewable energy sources.
4- The disadvantages of each form of renewable energy sources.
5- The way in which each form of renewable energy sources generates electricity.
6- Biomass is the only form of renewable energy that is a fuel.
7- The situations that biomass fuel would not be renewable.