It should come as a surprise to congressional supporters of the Energy Independence and Security Act (EISA), that their 2007 votes to expand the Renewable Fuel Standard (RFS) to advance “homegrown energy” would lead to historic U.S. imports of biodiesel. Here’s a look at how exactly that’s happening:

RFS requires 15 billion gallons of conventional biofuel in U.S. fuel.

But the U.S. fuel supply can only handle 14.3 billion gallons of ethanol.

Fuel Pump
U.S. Map

Though the conventional requirement can be met with various biofuels, corn-based ethanol is the most cost-effective and widely available biofuel of compliance.

No more ethanol can safely be added to the U.S. fuel supply due to lacking demand and infrastructure constraints.

15.0 billion-gallon conventional mandate
14.3 billion-gallon ethanol limit (due to infrastructure & market)



Q: How do refiners account for 700 million gallons of biofuel to comply with the RFS mandate if:

  1. There is no room for more ethanol in the U.S. fuel supply?
  2. Advanced biofuels – like cellulosic biofuel made from switchgrass – are not widely commercially available?

A: They comply with biomass-based diesel, the only other widely commercially available biofuel.

Not enough biomass-based diesel can be produced domestically to meet the 700 million-gallon conventional gap AND the separate advanced biofuel mandate of the RFS – which together add up to 3.2 billion gallons of biomass-based diesel needed. U.S. producers have failed to produce greater than 2.4 billion gallons of biomass-based diesel per year.

So foreign biodiesel is needed to help make up the 800,000,000 gallon shortfall.

In 2018, there were 164,346,000 gallons of biomass-based diesel imported to help the U.S. meet the RFS, meaning the RFS is a de-facto import mandate.

The RFS was made law by the Energy Independence and Security Act. More than a decade later, the failed policy has the unintended consequence of making us import-reliant for biodiesel, which is replacing American-made fuel at the pump.

Higher biofuel mandates mean more imported biofuel. This is not a win for U.S. farmers, ethanol producers, refiners or consumers. RFS volumes must be kept at domestically achievable levels.