Iowa’s renewable fuels industry accounted for almost $4 billion or about 2 percent of Iowa’s gross domestic product in 2020, according to a report commissioned by the Iowa Renewable Fuels Association.The report, written by Agriculture and BioFuels Consulting’s John Urbanchuk, shows the industry also provided $1.8 million in household income and 37,000 jobs.Biodiesel production increased in 2020, but ethanol production — which accounts for about 88 percent of the 37,000 jobs — faced myriad obstacles.Decreased fuel consumption during coronavirus, the U.S.