I think that is not only cool but also green. I think it looks like a space ship from Star Trek or maybe Star Wars.

How is a boat hull made of synthetic, factory-made artificial materials, powered by factory-made solar cells, any "greener" than a wooden hull sailboat?

Wind is ceated by the heat from the sun, thus "solar" kept early navigators and trade going many years before fossil fuel

What is "greener" about it is that many people prefer engine powered craft over sails. Not everyone is suited for sailing or wants the hassle and danger involved with sail power. Further, every sail boat of any size uses engines to power them when there is no wind or for navigating in tight quarters.
If this technology can be used to power ships that would otherwise use fossil fuels, then it is applying green technology to a niche that does not have any viable alternatives.

Can it be green if it's 4x's as big as needed? A 40' one at 25% of the weight, cost, drag would have been far better, more green, cost effective and practical.

It would be interesting to more about how it stored the sun's energy for use during non-daylight hours. Batteries? In 2006, there was some mention of hydrogen, but no details.

Believe none of what you hear and half of what you see. It is all about "facts" and "details".

Ah, great! Now to combine solar panels on the decks with flexible solar cells in the sails. That should add wind to the solar. More collection of energy? Throw in a diesel/electric hybrid powerplant and we have the ability to save lots of fuel on practical everyday boats/ships.

The facts of solar boats is they can move in a straight line with no tacking so even a slower water speed results in a faster arrival at your destination. Plus, the solar and the batteries cost about the same as sail rigging, masts and hardware. In addition, a catamaran has a much lower center of gravity on a solar boat compared to a sailboat and is much less likely to flip in severe weather. And the solar boat does not need to pollute the water and air with a noisy, stinky, very expensive backup diesel motor.

All this "green" talk is annoying and short-sighted. This is just cool technology. But I imagine the high power electronics are the Achilles heel of this craft.
Recently I crewed on a Lagoon cat that used to be a hybrid sailing cat. The rotating propellers in the water charged the battery banks while under sail (Cost about a knot of boatspeed which is a lot when you cruise at 7 kts)
When not under sail there was about enough power in the batteries to drive the boat for 1 hour after which the diesel generator needed to be started. Terribly underpowered vessel.
The killer was the fact that nobody around the world knows how to repair these things and the electronics in the salty sea air were not very reliable. I can tell you that that is not a good feeling when you manoeuvre the boat through some reefs in rough weather.
The boat has recently been converted to diesel to much relief of the owner and crew. All technology needs to be tried and that is cool. Over many years some things prove useable, most don't. The green argument at this early adopter stage is totally insignificant.