One fun way to teach kids about conserving energy is to have them become Energy Hog Busters. They can learn methods to conserve energy by playing a series of fun, educational games explaining the value of conservation.
Check out the Energy Hog Buster web site and become officially licensed to hunt hogs, not quite like having a 007 licence to kill but close (ok, not even close).
What I really like is that they took the concept of several mini-games and strung them together via a common theme and the fact that you earn a badge. This allows the game/instructional designer to create a series of related mini-games without having to develop a huge educational game with complicated plot, characters and graphics. Having concept of “earning a badge” underneath the game play of several games, you can create simple games but all related with an ultimate reward. Consider this type of design strategy next time you are creating some games for e-learning. (you are creating games for e-learning aren’t you?)