I came across the following brochure that gives a nice explanation of the various configurations and also some benchmarks for megayachts of different sizes.
They give an example of a 43m m/y taking anything up to 125 kw through shore power. Is this an accurate estimate?
I wonder how often yachts are finding that their demand is far greater than what's available from the shore - especially on a busy slip! Certainly some of the generators found on board the larger yachts boast obscenely large outputs!