Electrifying ferries can help us leverage crucial waterways while reducing emissions
February 08, 2023
Ferries are a critical transportation method for many communities near bodies of water. How can we make them more sustainable?
There is a new swell developing in the transition toward sustainable transportation. We aren’t talking about electric cars or electric school buses, but electric ferries. In years past, hybrid ferries—which combine diesel and electric power trains—led the charge. But in the last decade, a number of fully electric ferry services have been unveiled. The earliest projects were launched in Scandinavian countries, but electrified ferries are becoming increasingly common in North America as well.
Ferries are vessels that transport passengers and vehicles, and they typically operate with frequent scheduled crossings between specific points. They are a key component of transportation networks that allow travelers to predictably navigate bodies of water. For many communities, ferries are an essential component of getting around. They connect families, friends, and critical services amongst other things.
Below, we’ll explore how electric ferries can benefits communities and how ferry operators can implement the switch to leverage our crucial waterways while reducing emissions.
Ferries are vessels that transport passengers and vehicles, and they typically operate with frequent scheduled crossings between specific points.
The benefits of electrifying ferries
Transitioning from traditional ferries that are typically fueled by diesel to electrified alternatives offers a range of benefits. From a sustainability perspective, electrified vessels reduce greenhouses gas (GHG) emissions. However, the air quality benefits and noise reduction shouldn’t be overlooked. These benefits can be especially important when ferry ports are located in or near highly populated residential areas. Under the right conditions, electric ferries can also save money. And the economic benefits are only going to improve as the sector matures.
Depending on their location and operation, ferry size and energy needs can vary immensely. However, because ferries travel on well-defined routes and schedules, there are relatively few operational uncertainties. This makes estimating energy requirements more predictable. Smaller ferries with relatively short connections emerged as the entry point for electrification. But larger, faster ferries and longer routes are increasingly becoming electrification opportunities.
A 2020 study found batteries on hybrid and electric ferries had energy capacities ranging from 50 kilowatt-hours (kWh) to 5 megawatt-hours (MWh). On the low end of that range, the battery capacity is comparable to electric vehicles. However, at the high end of that range, a 5-MWh battery could power five and a half homes for over a month. As costs decrease and ferry manufacturers embrace this technological change, we can expect that the battery capacities will continue to increase.
From a technical standpoint, determining a ferry’s battery needs is only one part of the implementation challenge. When dealing with large energy capacities and short vessel port times, high power charging becomes a necessity. This can pose challenges for the electricity infrastructure. There simply may not be sufficient capacity at the docking site to ensure batteries can be charged in the loading and unloading time.
Depending on their location and operation, ferry size and energy needs can vary immensely.
Ferry electrification in Canada
The Wolfe Islander IV and the Amherst Islander IV will be some of the first ferries in Canada that can operate fully electric. These ferry routes play a crucial role in connecting island communities in Lake Ontario to the mainland. Because of their electric propulsion capabilities, the new vessels are expected to reduce GHG emissions by the equivalent of 7,000 tonnes of CO2 annually. In addition to reducing emissions, the ferries also have increased capacity. Collectively, it is expected that more than 1.2 million passengers and 600,000 vehicles will travel on these ferries each year.
In the planning process, it was identified that the local power grid had less than 1 MW of available capacity. But to maintain the scheduled 10-minute stopover time, the ferries required more than 2 MW of power. Upgrading the utility capacity to meet the terminal charging needs was determined to be both too costly and unable to meet the in-service dates of the vessels.
Our team was engaged to help solve this terminal charging capacity challenge. Turns out, the solution involved designing large stationary batteries at each of the ferry terminals. From the utility standpoint, these onshore batteries mean that the ferry charging requirements can be extended beyond the 10-minute stopover and instead over the round-trip ferry crossing. The onshore batteries are able to be charged at a lower, more feasible rate while the ferries complete their route. This alternative approach reduces the need for costly grid upgrades.
Electrifying ferries can provide many benefits, especially as we strive to leverage our water resources while reducing emissions for future generations.
Making the economics of such a battery work to simply relieve grid constraints can be challenging. This is where the value-stacking of battery energy storage systems comes into play. By oversizing the battery and leveraging the rest of the balance of plant equipment, the battery can also be used to offset the ferry terminal peak loads in a type of “load displacement” function, thus adding the benefit of peak demand reduction.
The onshore batteries ensure energy is available to charge the ferries’ operations and optimize the ferry terminal energy profile. The next engineering challenges are to safeguard the batteries for Canadian weather and to safely and reliability transfer that energy to the ferries’ onboard batteries in the short stopover timeframe. Responding to these challenges requires sophisticated modeling and site-specific design.
Adapting terminal facilities to support electrified ferries—and the necessary electrical infrastructure—can be a challenge. It’s safe to assume that when these sites were originally conceptualized no one was expecting multi-MWh batteries or major substation equipment. Reimaging site layouts to facilitate the transition to electrified ferries involves searching for creative solutions.
Our Company has been engaged to support BC Ferries with their conceptual planning around electrification.
Looking to the future
There is no indication that the transition towards electric ferries is slowing its pace. In North America, some major ferry operations are already signaling their intent to move towards electrification. Washington State Ferries—the largest ferry system in the United States—has plans to electrify their terminals and invest in fully electric and hybrid-electric vessels through 2040. BC Ferries is the largest ferry operation in Canada, and they have identified electrification as a long-term objective in their Clean Futures Plan.
Our Company has been engaged to support BC Ferries with their conceptual planning around electrification. BC Ferries operates large vessels with relatively long routes and, as a result, charging vessel batteries within existing stopover times is likely to require significant grid capacity. Our teams are assisting the exploration of different vessel charging strategies—be they direct from the grid or supported by onshore batteries—and considering how the needed infrastructure will impact terminal designs.
In Europe, Norway continues to lead the ferry electrification charge. The first fully electric car and passenger ferry was launched in Norway in 2015, and now the country has more than 60 fully electric and hybrid-electric ferries in operation. And their ambition hasn’t stopped. The Norwegian Parliament has established a zero-emission requirement for all cruise ships and ferries in the country’s UNESCO World Heritage fjords—a high traffic tourist destination—no later than 2026.
These institutional commitments and policy mandates are going to drive continued innovation in the electric ferry sector. Beyond improvements in vessel design, the toolkit and approaches for updating and adapting ferry terminals will become more refined. We will also likely see larger and faster ferries become viable electrification opportunities.
Electrifying ferries can provide many benefits, especially as we strive to leverage our water resources while reducing emissions for future generations.