Another experiment in habitat and the centerpiece of a tiny ecological footprint: My 1963 Mallard 15.  Ten feet shorter and two-thirds the weight of my beloved vintage Airstream, with more storage (in original birch paneling) and better amenities.  The roof-mounted solar is already in place.  Any changes to existing features will use technologies and designs from all my previous off-grid projects.   The tow vehicle is a biodiesel-ready 4x4 with commercial shell and sleeping platform.  This arrangement is off the scale of most ecological footprint calculators, but I will attempt measurements to share with my students.