> Personally, I'd imagine powering a Bollinger from a power wall and generator connected to a biogas digester that runs off the muck pile of a small horse or dairy farm.
If you control the timing of the supply of energy via the burning of the biodigested muck, why go through the Powerwall? The Bollinger's battery is 10x the capacity of the Powerwall. If you charge it directly from your generator, you don't have to pay the round trip charging losses of the Powerwall.
The only reason to use the Powerwall is to exploit solar power by charging the Powerwall during the day, and then drawing upon it at night to charge the truck.
Also note that according to this article [1] from Penn State University, all the reclaimable energy from dairy cow waste in Pennsylvania would only provide for 20% of energy used on Pennsylvania dairy farms. So it's not like there is going to be a surplus of electricity to charge your car. It would make more sense to use the biogas directly for the dairy operation, because you can potentially use both the electricity and heat from burning biogas to, for example, heat and power the cow sheds in winter, vs using that electricity to power a truck. The truck could get its electricity directly from solar, or from the grid.
1. https://extension.psu.edu/biogas-from-manure