"Big players with big, big sales volumes are moving very quickly into E15 programs," reports Michael O’Brien, vice president for market development at Growth Energy.

"What you’re seeing is the markets working as the competition is cashing in on E15 as a cleaner-burning fuel with a lower price point."

More gasoline chains are coming into the E15 market as a result, O’Brien says.

"You’re starting to see (the number of E15 fueling sites) doubling year in and year out that we were hoping to get."

There were 71 locations in the United States providing E15 in 2014. That’s grown to...