The lost revenue for not collecting excise tax on alternative fuels such ethanol would be very small, and it's really only required in the early stages to help in the commercialization.
I'd also like to add that the whole issue of excise tax on fuel needs to be revisited. The fact is that it is assessed on the basis of per litre. It was fine when 99% of the fuel sold for transportation was gasoline because it was all consistent. The reality is that all these other alternative fuels have generally lower energy density and are in various gaseous forms, so this per litre is inappropriate.
As an example today, the excise tax on ethanol, E85, actually charges 33% more per unit of fuel energy by doing it on a per litre basis in Canada than—