OK, see your direction now... If I were in your shoes, I'd start by looking at alternative energy generation methods, such as wind turbines or maybe water. (Wind is sometimes not there, and water dries up sometimes, but both can be relatively free other than the cost of equipment.)
I'll say that 20 years is a long time (good to plan ahead, though) and equipment will change substantially in those years.
But don't forget, diesel is basically the same as home heating oil, so there is another alternative source for fuel which may be available when diesel becomes less common. I'd certainly run my MEP-004 on home heating oil, no problem at all doing that. (maybe toss in a bottle of additive...)
