Why Nantucket’s Ferries Won’t Be Going Electric Anytime Soon

The Steamship Authority is exploring the feasibility of operating electric ferries, but the possibility of implementing such technology on the Nantucket route - at least at this point - seems to be a distant dream.

All-electric ferries would require significant capital investment both for new vessels and the infrastructure to support them, and would be far more feasible on the Steamship’s Martha’s Vineyard route than on the Nantucket route due to the greater distance involved.

Those are among the conclusions of the Hybrid Propulsion Study commissioned by the Steamship Authority and recently presented by its consultant, the Elliott Bay Design Group, a naval architecture and marine engineering firm.

“We keep coming back to energy,” said John Waterhouse, the founder and chairman of Elliott Bay Design Group, regarding the challenges of going all-electric on the Nantucket route. “The Vineyard route uses significantly less energy than Nantucket because it’s shorter. The drawbacks of Nantucket are, first of all, can you get rapid charging on both ends of the route? Our feeling is that’s not possible on the Nantucket route and at this current time.”

The Steamship Authority's fleet of 10 ferries and freight boats currently runs on diesel fuel, and together they consume roughly 3 million gallons in an average year on the Nantucket and Martha’s Vineyard routes.

As some coastal communities on the west coast and elsewhere begin to adopt hybrid and electric propulsion systems for their ferries to reduce emissions, the Steamship’s study was undertaken to explore a handful of options and provide cost estimates.

Those options included diesel hybrid systems and an all-electric option, but, as the study noted, “​​the Hyannis to Nantucket route is not being considered for all-electric propulsion at this time.”

The Elliott Bay Design Group estimated that both the capital and operating costs of all-electric propulsion were the highest of the options it explored, including the baseline of a diesel mechanical system. 

The study looked at an equivalent of the Steamship’s M/V Woods Hole to explore the alternative propulsion configurations - a vessel that would be a 235-foot passenger ferry intended for service on both the Nantucket and Vineyard routes.

To go all-electric on the Vineyard route with a boat of that size would require at least $12.2 million in capital costs, and $17.7 million in operating costs over a 10-year period. There was no corresponding cost estimate for Nantucket to go all-electric.

Another factor Waterhouse touched on was the source of electricity the ferries would need to draw from their “shore power” charging stations. In Washington State, where ferry operators are in the process of implementing all-electric vessels (albeit on shorter routes), they are drawing electricity from hydroelectric sources. That wouldn’t be the case in Massachusetts.

“If your electricity is coming from burning coal, and that electricity is powering your ferry, how green is that?” Waterhouse said.