Strength endurance would be like a long distance farmer walk, but since power is defined as being a product of work/time I'm not so sure there is such a thing as power endurance. Strength would actually factor into the power equation. I'll try my best to give an example, suppose you carry 70 lb dumbells for a mile in 15 minutes, carrying them that far and long is strength endurance. But say you try again the next week and it takes 14 minutes, still strength endurance but your power has increased, same work less time. I'm not sure that power and endurance go together since the ideal result for power in the example would be to shorten the amount of time to complete the task. Hope that helps, and if anyone else has insights I'd love to hear them.