The report includes figures 3.10-13 showing the right side collapse below floor 16 (?) at 0.5, 2.5 (shown above), 4.5 and 6.5 seconds, while the left side remains intact. Apparently everything above Column 79 drops down due to vertical failures' progression - there are free-flying parts. But the remainder of the structure below floor 16 is just locally damaged during 6.5 seconds. Nothing drops down from below = there is no free debris there. You would then expect the upper, intact part to tilt to the right!. The horizontal failures' progression is not clear.
What energy is required to produce all these failures?
Assuming you mean the ones in the figure, then none. If you remove the support from something, then it will fall.
The energy prior to these failure was that required to remove enough supports from around col 79 so that it was no longer stable, and hence buckled. After that there was a progressive collapse that required no additional energy.