Thinking about turning my diesel into a Greasel. The prospect of running veg oil sounds intriguing at the very least.
Talk about some nice retro-fitting of some parts. Especially if you want to be able to use used veggie oil, but even the new "pure" stuff can give you problems as well.
Trust me, my 6.0 PSD loves to drink and drink often, but if you actually crunched the numbers on everything associated with converting a vehicle to this, the C/B ratio doesn't make sense unless you are able to do fuel production and a pretty good scale. Not just the basic back yard'er.
As far as natural gas, hydrogen, electrical outlets for battery recharge stations etc, the infrastructure just isn't there yet. Now the one positive thing about raising prices on one input, that forces people to come up with alternatives or alternatives that were too pricey initially are now more viable. The most notable example is what happened with Whale Blubber and the coming of Kerosene.
The biggest thing for me is that whatever options that are explored, really need to be realistically renewable. I don't see the point of replacing one finite input with another finite input unless there is a long term plan. While inputs like oil are renewable from a geological standpoint, it doesn't do us any good for quite a few generations (if we are lucky).
Eventually this bullet is going to have be "bitten". After awhile we adapt and find ways to work around everything. It's what we do.