The wiring and electrical were installed in the studs of the container.   Plenty of outlets and eight 4" recessed cans in the ceiling.

The container was then completely insulated using Icynene spray foam, one of those wonder chemical concoctions that saves the environment, eliminates acne, and turns to water when a flame is applied.  (I'm not making this up.)  Even the inside of the swinging container doors were insulated with a thick layer of spray foam that looks like world's most wasteful application of butter rum icing.

Icynene is claimed to have an R-20 insulation value at a depth of about 6", and it was applied at this depth for much of the container.  That's about twice the R value of a wall in a typical home, and in this case the major culprit in insulating inefficiency --windows-- has been completely eliminated from the design.  You will see in a few days that we do have a design element that allows in natural sunlight, but at night the insulated doors are shut and the solar barn becomes in essence a giant Igloo cooler sealed off from the world.

The ceiling received an especially thick coat to block the thermal effects of overhead sun.

Next up:  Drywall.