Re: Tesla semi?
Air con only takes a few hundred Watts. The power usage will be lost in the noise. As electric motors are far more efficient that diesel there won't be the heat source in the first place.
The truck stops will have the mega-chargers so no engine required. I expect initial sales will be point to point though. General purpose will come later when the charging network has expanded out.
Finally, it'll still have normal brakes. They just won't, normally, be used much.