He could just call it a custom "camper" but then it would downplay that it runs on biodiesel, uses wind and solar power, and is made out of as much recyclable material as possible and is a drastic reduction in footprint than a house. And that would be selling it short...
Still doesn't really make it eco-friendly, you don't need solar or wind power...just need those things to run electric gadgets. All you need to do is to ditch the electronic gadgets.
We all have our own opinion which is a good thing, I dunno I am not seeing how a rig of that size (or any vehicle, no matter what powers it) being eco-friendly. Resources to build and fuel those vehicles have to come from somewhere, something has to be destroyed to create.