This is not exactly a cheat, but is certainly an exploit in the game (which may be patched in the future - or even by the time you read this now!).

It is a good technique for getting energy from virtually a zero position, even while preserving an Inspired status. To do it, pause the game by selecting the Shop icon. You should then open another tab in your internet browser, and do something else. Even though the game is paused, your Sim’s energy will continue to go up! You can be doing something productive while your Sim gets an Energy boost. This is a good way to save your Inspired status for when you have enough energy to make use of it – if you become Inspired when energy is low, pause, do something else for a while, then return and reap the rewards!