It would be cool to see how I rank among other students in energy points. There have been hand made lists before, but they have never been able to get everyone onto them. If there is privacy issues, people with energy points displayed publically can be listed onto it. But people with that section set as private, could still view themselves on that list (only they could see it) and see how they can compare. On this math website that my school district used before Khan Academy, there was a leaderboard there too, and it wasn't ever that much of a distraction.
Please take this into consideration.