@elleok hello dear friend, thank you very much for visiting and sharing your point of view, however, it is not something that has occurred to me, to call this floating mansion "self-sufficient" is the shipping company who have proclaimed it.
you can see here the publication

"The Mothership Houseboat is designed to be used all year round. Regardless of the weather she offers a comfortable platform and a great getaway. A large solar array keeps batteries charged, these can then be used either to power her electric motors or house appliances"

"Her large solar array means that she is self sufficient and non polluting. But over and above all of this, she is elegant, luxurious and is a joy to be aboard"

They will know what they have on board to be able to specify it in that way. I really appreciate your time in creating this excellent comment
I wish you a happy hunt