Here are some quick links for our energy unit.
Energy conservation and finding speeds
Gravitational energy 'the right' way
Finding tension for a pendulum (need energy to do so)
Springs and energy
Special relativity: one way to get the E = mc^2 result
Special relativity: energy equation to particle-wave duality
And if interested, how a nuclear power plant works. This video does a good job of showing the gist of the different parts of the plant facility.