Spaceships doesn't have a concept of power usage over time, as such, but it's utterly trivial to provide one and answer those questions in terms of PP*seconds. In keeping with the irritating current UT policy, PP aren't defined in any real-world terms, which might make it hard to hack together a capacitor bank system.
There hasn't been such a system in any of the first 4 books. Which would seem to be the ones most likely to have it, unless the Transhuman Spaceships I've seen mentioned is on the current list of planned releases.
There have been
efforts to dissect the elusive Power Point. The favored conclusion was that one PP = 1/20 MW per ton ship.