You don't. Parhaps you mean, how do you control yourself. In that case, you would exercise self-control and think about what Jesus would do in your situation. But you don't "harness energy within you" per say.
The idea is to harness the potential energy of the water, when it is at a certain height. The water has to be made to go down, to harness this energy.
No
buttholes
The energy of chocolate is harnessed by the simple expedient of eating it.
Energy in moving air.
yes
You can't really harness energy from it, since there isn't any stored energy (except for nuclear fusion, for which we don't have the technology yet). However, you can store energy as hydrogen, to retrieve it later.
Solar panels harness energy from the sun--Solar energy!
Wind turbines.
No, some protista and bacteria can harness the sun's energy also.
Electricity is the naturally occurring source of energy that we are yet not able to harness and use.
They harnessed the horse to the post.Imagine what might happen if it were possible to harness solar energy fully.