Okay, I was baffled by how turbines could generate electricity on a boat. Turbines could only take energy from the boat's forward motion, which makes it equivalent to a solar-powered flashlight. At night. I found that Gizmodo was also baffled, but Treehugger's article explained it:
The turbines engage when the boat is anchored and are driven by currents. The only power it gets that isn't solar is chance currents, while anchored. And I rather imagine that the flimsy transparent solar panels of the roof capture about enough energy to run the lights. = )
That is: I imagine most of its time will be spent idly charging, and that it produces more energy than it uses by sheer virtue of not using very much or, for that matter, doing very much. I mean, it passively takes in energy from motion and light, and then it's using that electricity to produce motion and light. With maybe a third of its upper surface covered in solar panels, plus random currents underneath, that's just not a hell of a lot of energy going in. Imagine 100% efficiency at every level, and it's still a very, very slow boat.
I don't honestly see how a huge, functionally useless conversation piece qualifies as "green" anything. Whatever reaction it's catalyzing in the water could be done without the boat.
But I get that it's primarily an awareness thing. It just sort of fails as a proof of concept.