US transmission developer Clean Line Energy Partners’ 4GW Grain Belt Express mega-project has hit a potentially serious snag in Missouri, with state regulators reportedly waiting to make their final decision until the legal battle over an unrelated transmission project has been resolved.

A prolonged delay would be a big blow to the long-gestating Grain Belt project, because the scheduled phase-out of the wind production tax credit (PTC) would change the economics of some of the Kansas wind farms set to take advantage of the proposed 780-mile (1,255km) line.