Here's an interesting, Aikido-specific reference to Elbow power (including an exercise) from Alex Essani
Aikido, Iron Balls and Elbow Power
Notice that the exercise seems to involve balancing a weight in such a manner that the local arm musculature isn't unduly responsible for holding the weight. This would be in-line (pardon the pun) with the video clips I posted from CMA. Of course, Essani's take isn't necessarily definitive nor mandated by heaven, but it's at least something substantive and congruent.
Dan, now that you seem to be back online: do you have any further comments re: posts #115