Each Greater Power can only be used once per game day.
http://www.uesp.net/wiki/Skyrim:Powers#Greater_Powers
Game time scale is 20 times faster than real time, so a day is 24 hours divided by 20 = 1.25 hours of real-time to recharge a Greater Power. https://www.youtube.com/v/JaAd8OuwwPk&autoplay=1&start=25&end=27 I don't want to use "sgtm" because it makes physics wonky and I'm in a location where I can't wait (Helgen escape).
So, is there a way—even via exploit, console command, or mod—to cleanly instantaneously cool down a Greater Power? Alternatively, is there a way to be able to use the wait option during the Helgen escape?