surprisingly enough that was a good offer...RJ!How about zero?
However science doesn't think of the propagating energy [universally] as one pole of a dual pole system. It likes to consider only one pole at a time.
Example: An object is charged to 13volts. What is often not mentioned is that for the object to have a charge of 13 volts it also must have a negative charge of 13volts.
so we have a charged object at (+)13v + (-)13v and guess what?... that sums up to zero. So how much charge is present?
The real question is how can (+)13 volts and (-) 13 volts co-exist with out annihilation to zero?
As I mentioned in another thread the answer to that lies in another aspect of the system that appears to be missing.
the charge can only exist if "a span of time" is present.
so we have (+)13v + (-)13v + (t=delta >0) = 0. this way charge can co-exist with zero.
Therefore the "potential to do work" (energy) is dependent on having the time to do it in.

Please assume t=>0 refers to time duration
So a Zero Energy Universe, as you linked to, can not exist simply because time is present
Just a few thoughts......