[VLM]

"Probably a nice big diesel."

There's an interesting synergy with other technologies. For example, its pretty trivial to prove you'd have to cover the surface of the earth with a ridiculous number of sunflowers to grow enough oil to power the world with biodiesel using existing vehicles.

However, if 99.9% of car miles driven were solar electric, if not more, then its quite realistic to power every rental truck in the world off biodiesel.

My lifetime driving so far is around 200K miles, and I've driven the home depot truck, enterprise rent a car, and u-haul trucks a total of perhaps 200 miles, so a thousandth of miles driven being biodiesel powered doesn't sound terribly unrealistic on average.