Do you exude energy? Now this is related to volume because if your volume is really low, you're not gonna sound energetic but it's not just about speaking louder. Do you have some enthusiasm in your voice? Are you captivating? Do you look and sound like you're having fun? These are important things so you don't want a flat, lifeless voice and you want variety in your voice.
That is what will make you filled with energy and sound energetic.