The newest passenger boat for Maine's Casco Bay Lines will be running a diesel-electric hybrid propulsion engine. The hybrid will be handling the Portland to Peaks Island run, fully on electricity. The diesel engine will function as a backup, or be engaged for trips longer than the normal run. This assigned route is approximately 2.5 miles, which should allow the ferry to travel one way, charge at docking (~10-15 minutes) and run the return trip on electricity as well.
If you aren't familiar, Casco Bay Line's ferry runs all year round and carries over a million passengers, 30,000 vehicles, and 5,300 tons of freight in a given year, so they are a critical part of transportation in Maine,. The ferry functions as a vital link between the islands & main lands that allows for commuting to school, work, and postage services.
The project is being funded in part by a Federal Grant as part of the Federal Transit Administrations Ferry Grant Program. Vessels essentially hit a point where maintenance becomes cost prohibitive (after about 30 years of operation), and the grant for this particular ferry project will replace one such vessel. The replacement with a hybrid is projected to eliminate up to 800 metric tons of carbon emissions annually. The new vessel should be completed and in operation by the end of 2022.
I wrote an article for Oil & Energy this month about the Casco Bay project, as well as the Federal Fund Grant generally. You can read that article in its entirety here: A Ferry Different Approach