Here’s my little project about self-supply with thermal energy 
I chose to showcase this first because @alberto wanted a photo:
This is a simple oven installation in the truck that I intend to live in. I started from a small wood stove that I got as a gift. Placed it 20 cm from walls to prevent any danger from the heat (sheet metal heatshields with 20 mm air gap to the walls still to be added …).
Mounting for offroad driving conditions was kind of a challenge. So first I created a steel band, from 2.5 mm steel sheet metal ripped from a dead road roller’s roof. It is mounted around the top of the stove, then bolted with two big bolts right through the box body wall of the truck, and has a L-profile cross-section behind the stove for reinforcement (not pictured). Two feet of the stove are bolted to the metal socket in the right of the image. Appears really solid now, and has the advantage that I can store objects uninhibited by mounting beams etc. to the left of the stove.
The wall duct through the 10 cm wall is done with a large hole, covered in blue aluminum in the image, stuffed around the oven tube with rockwool for heat protection. At the outside, there are 2 pieces of 1 m oven tubes, with one special feature as per a friend’s idea: the upper tube is detached when driving, and then slides behind the lower one into a metal box storage casing. Its top lid then fits as a rain protection lid on that storage box, level with the box body roof.
Phew … it was important that I got this done before the winter 
I’ll add a diesel based independent vehicle heating some day, but for the first time, this is enough already. And, above all, it’s free. (There is so much unused deadwood in the woods and paper in people’s paper bins … for the latter I need a paper pelletizer machine though).