How many energies can be placed per single turn: one per Pokemon to as many Pokemon in play, one per turn period, only to active Pokemon, or what?
You can attach 1 energy card per turn. But the Emboar from Next Destinies set(if Im not mistaken with the sets) has the abilityInferno Fandango. This allows you to play as much as Fire energy during your turn.
You may only play one energy card per turn. Use the option wisely.