Radio Iowa: A northwest Iowa ethanol plant suspended production this week “until further notice.” Plymouth Energy in Merrill is one of at least 10 ethanol plants in the country to temporarily shut down. Three others have closed. “A lot of the experts say we’ve got about a 10% overage of production, and until that production comes off line, the economics aren’t going to improve,” Iowa Renewable Fuels Association Executive Director Monte Shaw said. Shaw said this supply-demand imbalance is caused by waivers that federal officials are granting big oil companies — so refiners don’t have to blend as much ethanol into gasoline.