It's not a long range vessel, but it should have a fairly long service life.
Additional weight and complexity on a one off boat would be more expensive than a seperate much more standard solar and battery system on land. And you might be able to get additional value out of selling electricity from an oversized storage.
It's not sensible to draw your system boundaries around the boat by itself; there is significant terminal infrastructure; and even grid electrical infrastructure to consider.
What exactly is the benefit of having solar panels on the ship? Her accumulators are more than capable of supplying all the electric needs during her ferry trips. Placing 0.002 square kilometer of solar panels on land is cheaper.
Additional weight and complexity on a one off boat would be more expensive than a seperate much more standard solar and battery system on land. And you might be able to get additional value out of selling electricity from an oversized storage.
It's not sensible to draw your system boundaries around the boat by itself; there is significant terminal infrastructure; and even grid electrical infrastructure to consider.