Do you have a study of this idea? At first glance it seems that the problems of fermentation, transportation, and resources needed to produce at that scale would be too large to overcome.
Fermentation might not be a problem, I'm hoping the switchgrass would be harvested when very dry, to cut down on that. Grass for silage, (which ferments) is cut when green, but hay is dry and does not ferment.
Transportation and resources would be something, yes, but if you take a look at what we've built to make use of hydrocarbons, I think we could manage.