SECTOR 04 / VESSELS, TERMINALS & POWER
A battery, a charging system, and a terminal do not become an operating service until their assumptions agree.
THE SHORT ANSWER
Marine electrification can involve onboard propulsion energy, electrical supply at berth, charging infrastructure, or several of these together. A credible plan connects the service schedule to vessel requirements, the terminal, the utility, and the people who will operate the system. Define what electricity must do and when it must be available before comparing equipment.
Route schedules, charging windows, and terminal readiness belong in the same conversation.
Scope a shore power project by clarifying onboard loads, berth arrangements, utility requirements, operating windows, and ownership.
Vessel electrification concerns propulsion and onboard energy. Shore power supplies a vessel while berthed. High-power charging replenishes onboard energy within an operating window. A project can involve more than one, but they should not be treated as interchangeable requirements.
Begin with the service to be delivered. Map route conditions, turnaround time, layover windows, berth availability, and maintenance access. Qualified vessel, electrical, and utility specialists can evaluate technical requirements against that common operating brief.
| Interface | Input to establish | Owner to identify |
|---|---|---|
| Schedule → vessel | Energy use and operating assumptions | Vessel technical team |
| Vessel → berth | Charging window and connection arrangement | Vessel and terminal teams together |
| Terminal → utility | Supply needs, connection process, lead time | Utility and shoreside electrical team |
| New equipment → operation | Training, support, maintenance, transition | Operating owner and suppliers |
Washington State Ferries describes its electrification work as a combination of new vessels, terminal infrastructure, and charging systems. That is a useful way to understand project dependencies. Its scale, schedule, and funding are specific to that program.
A study for another route needs its own assumptions, technical work, costs, and implementation sequence. Our planning guides explain what to ask for before turning a concept into a procurement package.
EPA’s shore power assessment discusses supplying auxiliary loads at berth and evaluating emissions effects. A ferry propulsion-charging brief has an additional schedule and onboard-energy problem. Make the intended function explicit so providers are answering the same question.
| Project concept | Purpose to clarify | Critical planning question |
|---|---|---|
| Shore power at berth | Supply onboard loads while a vessel is connected | Which loads, vessels, berths, and connection periods? |
| Propulsion battery charging | Replenish stored energy for operation | How much energy must transfer in the usable window? |
| Hybridization | Combine propulsion or energy arrangements within a defined vessel system | Which operating modes and technical alternatives are being evaluated? |
| Fleet transition | Introduce changes across assets and service patterns | Which vessel, terminal, workforce, and utility dependencies control the sequence? |
Collect the pattern of work the system needs to support: routes, visits, operating hours, layovers, boarding activity, seasonal variation, and the availability of alternative berths or assets. Give every input a source, a date, and an owner. The technical team should distinguish measured information from screening assumptions.
Connection time is not automatically the full time spent alongside. Berthing, connection, passenger handling, disconnection, and departure may interact. Ask the operating and technical teams to establish the usable window together. A schedule change can materially change what is required from the vessel and shore equipment.
Record future service changes separately from the current baseline. A proposed longer route or additional vessel can be evaluated as an alternative. Hiding it inside an unspoken “future-proofing” assumption makes it harder to understand what the initial project actually needs.
Illustrative screening example: suppose the team is examining a requirement to transfer 450 kWh in a 12-minute usable window. Twelve minutes is 0.2 hours, so the simple average energy-transfer rate is 450 ÷ 0.2 = 2,250 kW, or 2.25 MW. If that usable window is only eight minutes, the same arithmetic gives 3.375 MW.
These are not charger ratings, utility requirements, or a design recommendation. The calculation leaves out losses, charging behavior, vessel constraints, other loads, reserve assumptions, and technical acceptance requirements. Its purpose is to show why the actual timetable and connection sequence belong inside the study.
Ask the study team to document the energy basis, the usable time window, and sensitivity to changes in both. The owner should be able to see whether an apparent infrastructure requirement comes from measured operating needs, a conservative assumption, or a service pattern that could be reconsidered.
The U.S. Department of Energy’s maritime energy and emissions action plan emphasizes collaboration between ports and utilities over shore-power supply and wider electrification demands. For a specific project, establish the utility’s actual process; do not replace it with a generic delivery timeline.
| Bring to the conversation | Clarify with the relevant team | Record afterward |
|---|---|---|
| Vessel and charging scenarios | What supply information is needed to assess each option? | Inputs still to be established by vessel specialists |
| Berth and site arrangements | What access, space, and interface constraints need investigation? | Responsible team and evidence required |
| Operating windows and service periods | How does the demand pattern affect the assessment? | Assumptions to test and scenarios to compare |
| Target implementation sequence | Which utility, equipment, and site milestones are dependencies? | Decision dates and the basis of lead-time assumptions |
| Ownership and maintenance model | Where do asset and service responsibilities change hands? | An interface register with named owners |
Compare alternatives against the same service and study period. Ask the cost team to identify electricity and fuel assumptions, tariff structure where applicable, upkeep, support, equipment replacement assumptions, and any costs retained by another party. A purchase price alone is not a lifecycle comparison.
Keep uncertainty visible. If energy use or the operating pattern changes, show which cost inputs move with it. If a utility charge depends on the demand pattern, ask the relevant specialists to evaluate that pattern rather than using an undifferentiated cost per unit of energy. We do not publish a universal savings percentage for these projects.
For emissions evaluation, state the boundary and the method. EPA provides an assessment and calculator for shore power at berth; the underlying vessel and electricity assumptions matter. Do not describe a local reduction at the vessel as an independently verified claim about the entire energy system. Ask for the evidence supporting the claim actually being made.
The owner needs a documented baseline, technical assumptions, alternatives, interface responsibilities, an implementation sequence, and a list of unresolved decisions. Each conclusion should make clear what evidence supports it and what additional work is needed before procurement or delivery.
Use an interface register to connect the packages. For each requirement, record its source, owner, affected team, decision date, and consequence if it changes. A charging-window assumption affects more than the vessel; a terminal or supply constraint can affect the operating plan. A register makes those connections reviewable.
Washington State Ferries’ public program combines vessel, terminal, and charging initiatives. That is useful evidence of the need for system coordination, but its scale and timetable should not be copied onto another service. Elliott Bay Design Group and KPFF publish related planning and technical work that can help readers identify the disciplines to investigate.
A functioning project needs more than delivered equipment. Identify the teams responsible for testing, acceptance evidence, operating procedures, staff preparation, support, and maintenance. The relevant technical and operating specialists should establish the actual service requirements and release conditions.
Walk through a normal operating period and an exception. Ask who receives a fault report, who decides the next operational step, how the service team communicates changes, and which records are retained. Confirm responsibilities across the vessel owner, terminal, utility, suppliers, and operator before the asset is introduced into service.
Keep an explicit distinction between a successful demonstration, technical acceptance, and readiness for the intended operating pattern. Those may be separate milestones. A clear handover shows which milestone has been achieved and which dependencies remain with the owner or another team.
TAKE IT INTO YOUR NEXT MEETING
Use these prompts to turn the research into a specific assignment. Capture what is known, what still needs evidence, and who owns the next decision.
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Not necessarily. Shore power can supply onboard loads while a vessel is berthed. Propulsion charging replenishes stored energy for vessel operation. The project brief must identify the loads, operating window, and interfaces involved.
Early screening can begin, but assumptions about supply capacity, connection works, and lead times need to be tested with the relevant utility and electrical specialists before committing to delivery dates or equipment requirements.
A simple screening calculation divides the energy to be transferred by the usable charging time. Technical analysis must then account for charging behavior, losses, vessel and shore constraints, other loads, and operating requirements. The screening result is not an equipment specification.
The project team must assess the actual vessel, load, berth, supply, and operating arrangement. An existing terminal connection should not be assumed sufficient or insufficient without relevant evidence and technical review.
There is no useful single duration across projects. Vessel work, utility assessment and connection, terminal works, equipment supply, acceptance, and workforce preparation can have different dependencies. Request an evidence-based sequence from the project team.
EPA discusses reductions associated with supplying onboard loads from shore at berth. Any broader claim depends on the boundary, vessel behavior, electricity assumptions, and evaluation method. State precisely which emissions are being assessed.
The project may require vessel and electrical specialists, terminal and utility teams, operating staff, procurement support, and other site-specific expertise. Appoint a lead for shared assumptions and interfaces rather than treating each package as an isolated project.
The sources below document published capabilities, programs, or frameworks. Decision tools, scenarios, calculations, and procurement prompts are our editorial analysis. Illustrative examples are not completed client projects.