If you are good at power naps (i.e. can drift off in under 10 minutes in the right conditions) you can try a tea rebound nap; make a strong cup of tea and drink it quickly just before you lay down for a snooze. You'll drift off before it hits and by the time your 20-25 minute timer finishes your brain is doubly refreshed.
I find the 'hard-reset' aspect of a nap to be essential some days, and it is completely different in nature than the 'energy' aspect. More to do with unresolved problems to solve than actual energy.