it would probably be more efficient to make only a partial animation, then use scripting to change the frames around. that way you don't have to store as many frames.
most glow maps on shivan ships simply ramp up and down ad continuum . this effect is not only rather boring but also really inefficient. if you were to script the effect, you could get away with only having half the frames, the effect could ramp up, then the animation would run in reverse for the ramp down. you could take it a step farther and occasionally ramp up half way on a random basis, which would add a bit more variety to the effect.
taking it a step further i believe its now possible to generate rtt glowmaps which would be generated with script on the fly. this reduces the texture count to 1 (plus any other maps you may use as elements which are rendered into the glow map).
combine either meathod with glow points you can make even more effects.