Port Electrification Series, Part 4

Reaching net-zero carbon emissions is a complex challenge for harbor operations. While electric tugboats solve one problem, they introduce another: energy delivery. Multi-megawatt-hour batteries can power these harbor tugs, but conventional EV infrastructure can’t recharge them sufficiently to meet their strict timetables. To operate efficiently, a charging solution must account for both speed and magnitude.

Each year, over 1,800 vessels arrive at the Port of Los Angeles alone. In 2025, 17% of all containerized international waterborne trade in the United States traveled through this port, with a total cargo value over $300 billion.

The Port of Los Angeles is just one of hundreds of ports throughout the United States, each one a complex operation that requires meticulous, tightly scheduled windows to operate effectively. When tugboats are unavailable, vessel movements slow, timelines shift, and a significant portion of the American economy is impacted.

Harbor tugs are under load constantly throughout the day, with short turnaround times between assignments. When these tugs are electrified, a new logistical concern arises: ensuring they can be charged quickly and reliably.

Unpredictable charging windows would massively disrupt harbor operations. Congestion would increase, arrival windows would begin to overlap, and delays would compound across the port. Delays cannot be absorbed into the schedule; they would completely disrupt the schedule.

The right charging solution is critical to the success of harbor operations.
 

Speed and Magnitude: The Charging Requirements for Harbor Tugs

Standard EV fast chargers deliver anywhere from 50 to 350 kilowatts (kW) of power. The passenger EVs utilizing these chargers often charge overnight, with long charging sessions merely posing a personal inconvenience to the vehicle’s driver and passengers.

Charging a single electric tugboat requires multiple megawatts of power—far beyond the capabilities of a standard fast charger for just one tug.

Consider that the average US household consumes approximately 10,500 kilowatt-hours (kWh) of electricity each year. By this standard, 1 megawatt of electricity can power over 800 homes in the US for a year. Taking into account the power requirements of, for example, an electric tug with a 6 megawatt-hour (MWh) battery, we see that delivering power for harbor assist vehicles more closely resemble industrial electrical demand than vehicular charging requirements.

Recharging even half of a 6 MWh battery through conventional charging systems would lead to hours-long delays and significant disruption to shipping operations. Charging a fleet of electric tugs in minutes requires a newer, stronger charging solution.

This solution is in practice by tug operator Curtin Maritime, who has met the challenge of executing the Port of Los Angeles’ decarbonization goals by not only having its electric fleet built by Arc Boats, but by also having its megawatt charging infrastructure designed and built by Motive Energy.
 

Up Next: Battery Solutions Designed for the Port Infrastructure

Keeping a fleet of electric tugs available for continuous, overlapping duty at one of the busiest ports in the Western Hemisphere requires an immense amount of charging capability, a capability that many ports were not designed with.

For ports such as the Port of Los Angeles to implement cleaner technology without disrupting operations, not only must the boats evolve, but waterfront infrastructure must also evolve with them.

In the next installment of our Port Electrification series, we’ll address the next challenge facing the Port of Los Angeles and its partners Curtin Maritime and Arc Boats: how to deliver megawatt charging safely and reliably on the water.