14-18 energy is the standard amount. I was a judge at one of the Cities and from deck-checking I can say that no-one had over 20 energy in there deck. Infact, I haven't seen anyone but little kids with over 22 in there deck.
If you don't know what you're talking about then I request you don't offer advice.
I have 28 energy in my deck and I need most of them If not all off them.