It depends on context. I'm assuming that
@FeatsofPower made this thread in response to the discussion we had which in that case, when I say ki, I meant energy. The way characters mention ki often refers to power. I just assumed Feats was referring to the Buu meter specifically where I mentioned that the Buu meter explicitly draws upon the total energy of the fighter. Goku and Vegeta exhausted a lot of energy during their fight but that doesn't mean their power dropped by the same amount. We know this to be true the very moment Raditz died. Piccolo exhausted a lot of energy but his power remained intact.
The reason why power and ki/energy seems synonymous is only because characters make judgements about a fighter's ki based on what they sense and ki sensing serves as a replacement for scouters which detect one's overall battle power. In general, the stronger the fighter, the more ki or energy they will have. But, that doesn't mean their power drops in proportion to the ki they expend. Otherwise, every fighters' power drops the moment they throw a ki blast and we know that's blatantly not true. Even Super Saiyan 3 Goku grappled with Kid Buu for a while before his power dropped and that is one of the most energy-intensive techniques in the series.
Hopefully that clarifies things. I don't want the argument to boil down to semantics.