The mandate only specifies the volume of ethanol to be included in the fuel supply; it does not mention what source is to be used.
The subsidy is paid as ethanol is blended with gasoline. It is paid regardless of the source of ethanol, included imported sources. (note, we are now an exporter of ethanol since we produce more than we use)
So we are now subsidizing other countries at 47.5 cents/gallon? And if we didn’t slap a 54 cent/gallon tariff on Brazilian ethanols we WOULD be an importer and save taxpayers money.
Bottom line: It costs 65% more energy to produce ethanol than the energy we derive from ethanol. If it wasn’t a subsidy program, why would we do it?