Smart grid upgrades may offer less risk in some areas, but experts say conventional transmission projects are still needed in others.
Proponents say the Cardinal-Hickory Creek line is needed to increase grid stability. Critics call it unnecessary.
Previous cost estimates have not been updated since the state proposed a utility tunnel under the Straits of Mackinac.
Amid some disagreement, a draft of the Illinois NextGrid report is open for public comment online until January 10.
A recent report spotlights so-called non-wires alternatives to expensive transmission line upgrades.