Toronto's Marilyn Bell Shows Why Ferry Electrification Starts at the Dock

The Marilyn Bell I, operated by PortsToronto for Billy Bishop Toronto City Airport, remains one of the clearest North American examples of practical ferry electrification: a 2010 Ro/Ro ferry converted to 100 per cent electric operation, supported by renewable electricity and automatic shore charging.

Some of the most important maritime decarbonisation stories are not the largest. They are the ones that show how the system works.

Toronto's Marilyn Bell I is one of those stories. The ferry operates the short crossing between the city and Billy Bishop Toronto City Airport, carrying passengers, vehicles and supplies across the harbour. On paper, it is a small vessel: a 29.26-metre Ro/Ro ferry, built in 2010, with a moulded breadth of 11.5 metres and gross tonnage of 270 tonnes. In policy terms, however, it is a useful case study in how electrification becomes real infrastructure rather than a presentation slide.

CANAL Marine & Industrial's project profile sets out the technical and delivery role behind the conversion. CANAL lists its contributions as design optimisation, a 100 per cent electric engineered solution eliminating diesel engines, delivery of the technical solution package, RFP support, contractor selection, contract scope negotiation, execution management, automatic shore charging and ongoing maintenance. That list is important because it describes electrification as a managed project, not simply a battery purchase.

The project was led by PortsToronto, owner and operator of Billy Bishop Toronto City Airport. In July 2021, PortsToronto announced the final phase of the Marilyn Bell I conversion, with the vessel sent to Toronto DryDock. The new propulsion system was designed to be entirely battery powered and supplied by 100 per cent Bullfrog Power renewable electricity. The objective was direct: remove greenhouse gas emissions from the airport ferry operation and reduce operating noise in the surrounding community.

When Marilyn Bell I returned to service in December 2021, Green Marine described it as Canada's first electric ferry service powered by a zero-emission lithium-ion propulsion system with no diesel components. The vessel had been in operation since 2010, had moved to bio-diesel in 2018, and then had its diesel generators and engines removed in 2021 to make way for the new electric propulsion system and lithium-ion batteries.

The emissions impact is material for a vessel of this size. Billy Bishop Toronto City Airport says the conversion eliminated nearly all greenhouse gas emissions from ferry operations, reducing the airport's Scope 1 emissions by approximately 530 tonnes per year. The airport also links the conversion to a broader cleaner, greener and quieter operating strategy, including renewable electricity procurement, compact battery-powered security vehicles, anti-idling policies and electric shuttle buses.

This is where the story becomes relevant far beyond Toronto. Ferry electrification is often discussed as a vessel technology question. The Marilyn Bell experience suggests the better question is wider: can the vessel, the dock, the power supply, the operating timetable and the maintenance model be designed together?

The automatic shore charging element is especially important. Short-route ferries are attractive candidates for electrification because routes are predictable, dwell times are known and operating profiles are repetitive. But those advantages only become bankable when charging is dependable. A ferry that works every day needs a charging system that fits the berth, the schedule and the crew workflow. Otherwise, the emissions ambition becomes an operational risk.

Marilyn Bell also shows why retrofits matter. Many ferry fleets will not be replaced overnight. Existing vessels still have asset life, political value and operational familiarity. A well-executed retrofit can therefore accelerate emissions reduction without waiting for a full newbuild cycle. That is an important lesson for smaller ferry operators, island routes, airport links, harbour crossings and municipal transport agencies.

There is also a public acceptance dividend. PortsToronto and Billy Bishop Airport emphasise that the electric ferry operates much more quietly, reducing the noise footprint of airport access for the surrounding waterfront community. In dense urban ports, that matters. Cleaner propulsion is not only a carbon measure. It is also a quality-of-life measure for people living near the quay.

The recognition that followed is telling. Billy Bishop Toronto City Airport received a 2023 Airports Going Green Honorable Mention for its project to make access to the airport electric. The Marilyn Bell conversion was presented as the catalyst for a wider shift, including electric shuttle buses that would further clean the passenger journey to and from the airport.

For Europe and the Mediterranean, the Toronto example should be read carefully. Many ferry routes are shorter than the industrial debate makes them appear. Harbour ferries, river ferries, island shuttles, airport links and port service vessels often operate on fixed routes with regular charging opportunities. Their decarbonisation challenge is rarely just whether batteries can move the vessel. It is whether the operator can coordinate shore power, grid capacity, berth automation, procurement and maintenance into one reliable service.

Electrification becomes meaningful when it moves from isolated pilot to dependable service. Marilyn Bell is valuable because it links the vessel to the dock and the dock to a wider institutional strategy. PortsToronto, Billy Bishop Toronto City Airport, CANAL and Bullfrog Power each sit in a different part of that system, and the result is a working example of how local maritime transport can reduce emissions while improving community conditions.

The lesson is simple, but not small. The future of clean ferry operations will be built around systems: predictable routes, automatic charging, renewable electricity, clear ownership, good engineering and maintenance that keeps the asset moving. Toronto has already put that combination into daily service.