Natural gas was possible but would require more capital up front, a lot more space and a specially prepared site for the tank, annual safety inspections and a place for a 40' truck to deliver it and turn around again (and of course it still required the genset itself). Diesel was by far the easiest solution, especially because we used the generator infrequently and once the windmill was up not at all.

We used wood for heat and limited shelf life for diesel is not an issue at all (it is for ethanol based gasoline).