Oxygen
look at the periodic table and it says it
1. It is something we don't have to worry about ever losing.
2. We can use quite a bit of it.
3. Renewable energy saves us from wasting non reusable energy
4. We have something to use when we run out of non reusable energy
5. The energy is is helpful with everyday things.
By weight the hydroxides are 45.9% of the weight