Electric ferries and port charging: how ships plug in

What battery electric and hybrid ferries are

A battery electric ferry runs entirely on energy stored in onboard lithium ion batteries. It recharges from the shore grid while it berths, so it burns no fuel and produces no exhaust at sea or in port.

A hybrid ferry combines batteries with diesel or dual fuel engines. The batteries handle peak loads, manoeuvring and port stays, while the engines cover the open sea leg and recharge the batteries underway.

The choice depends on route length, crossing frequency and grid access. Short, frequent crossings with predictable dwell times suit full battery operation. Longer or less predictable routes usually start with hybrid systems and add battery capacity over time.

Notable electric and hybrid ferries in service

Norway's Ampere opened the sector in February 2015 on the Lavik to Oppedal crossing of the Sognefjord. Norled reports that one crossing uses only 150 to 200 kWh and that the ship saves about one million litres of diesel and more than 570 tonnes of CO2 a year.

Scale has grown quickly since. Bastø Fosen's Bastø Electric entered service on the Moss to Horten route in 2021 with a 4.3 MWh battery, 200 cars and 600 passengers. Ærø Municipality's Ellen carries the same battery size on a 22 nautical mile route between Søby and Fynshav.

The largest battery ship in service is China Zorrilla, built by Incat in Hobart for Buquebus. It carries more than 2,100 passengers and 225 vehicles across the Río de la Plata on a battery system of more than 41 MWh supplied by Corvus Energy. It entered commercial service in October 2026.

Hybrids now operate on Europe's busiest short sea routes. P&O Ferries' double ended P&O Pioneer on Dover to Calais carries up to 8.8 MWh of batteries alongside four diesel engines.

How ferries charge in port

Ferries charge during the minutes they spend loading and unloading. The connection must therefore be fast, automatic and safe in all weather and at every tide.

Three main methods are in use. Automated plug in systems move a shore cable to a socket on the hull; Bastø Electric uses a Stemmann system with a charging unit on each side of the ship and a vacuum coupling. Charging arms and towers reach down from the quay or ramp; Ellen's arm sits on the shore ramp and follows the tide while cars load. Robotic connectors use sensors to find the socket; ABB's shore stations for ForSea's two ferries use an industrial robot guided by 3D laser scanning.

Charging power has risen with battery size. Bastø Electric charges at up to 7.2 MW. China Zorrilla's terminals each have two 15 MW chargers, sized to restore the battery between each of four daily crossings.

Charging standards for ships: IEC/IEEE 80005, ISO 15118-20 and MCS

Ship charging draws on two families of standards. The first is shore connection, built for ships that plug in to run hotel loads at berth. IEC/IEEE 80005-1 covers high voltage shore connection, and IEC/IEEE 80005-3:2025, published in December 2025, covers low voltage shore connection for ships needing up to 1 MVA.

The second family comes from road transport. The Megawatt Charging System (MCS), driven by the CharIN industry association, defines conductive DC charging at up to 3,000 A, with the connector formalised as IEC TS 63379. SAE published its MCS guidance as SAE J3271 in March 2025, aimed at heavy trucks and buses.

MCS matters to ports because one connector type could serve harbour craft, small ferries and electric port vehicles. CharIN states that parallel MCS connections can deliver up to 12 MW for commercial and large vessels. It names ISO 15118-20 as the communication basis for marine MCS and CCS charging.

Marine MCS is not yet a settled maritime standard. CharIN launched a Task Force Marine in June 2025 to map charging needs across ferries, tugs, workboats and barges. Large ferries today mostly use project specific AC or DC solutions. Port owners should specify interoperability early and track IEC work before fixing connector choices.

Grid capacity and battery buffers

A ferry that charges at several megawatts for ten minutes places a sharp, repeated load on the local grid. Many ferry quays sit on weak rural networks that were never designed for this.

The common answer is a shore battery buffer. The buffer charges slowly from the grid between calls and discharges quickly into the ship when it berths. Norled installed battery buffers on both berths for Ampere because the grid at Lavik and Oppedal had limited capacity.

Larger projects need new grid capacity as well. Uruguay's state utility UTE installed a new grid cable to supply China Zorrilla's terminal. Port planners should engage the grid operator at the concept stage, because grid reinforcement often takes longer than building the ship.

Electric tugs and harbour craft

Tugs suit electrification because they work short jobs close to a fixed base and return to the same berth to charge. Their peak power is high, but average energy use per job is modest.

Ports of Auckland took delivery of Sparky, a Damen RSD-E Tug 2513, in 2022. It has a 2,800 kWh battery, 70 tonnes of bollard pull, and recharges in about two hours from a quayside connection of around 1,400 kW. It can complete two or more assignments between charges.

Pilot boats, crew transfer vessels, workboats and harbour ferries follow the same logic. These are the vessels where a common MCS style connector would give ports the most benefit.

Costs and payback

Battery ferries cost more to build but less to run. The extra capital goes on batteries, lighter hulls, shore chargers and grid connections. Savings come from lower energy costs, simpler maintenance and the absence of fuel.

A 2015 feasibility study published by Siemens estimated that 84 of Norway's ferries could switch to full battery operation for about €384 million of extra investment. It put the resulting operating savings at about €77 million a year, on top of avoided emissions.

Shore infrastructure is a large share of the bill on big projects. China Zorrilla's chargers cost about US$14 million, and the new Uruguayan grid cable about US$20 million. Payback therefore depends on local power prices, crossing frequency, contract length and who funds the shore side.

EU rules strengthen the case. The EU ETS and FuelEU Maritime place a growing cost on fossil fuel burned by ships of 5,000 GT and above. Electricity drawn from shore produces no emissions on board, so it carries no ETS allowance cost.

Questions, answered

1. Norled: MF Ampere marks its 10th anniversary
2. Corvus Energy: MF Ampere success story
3. Riviera: Bastø Electric technical details
4. Danfoss: Ellen battery and charging
5. Ellen (E-ferry) reference entry
6. ChargedEVs: Corvus Energy 41 MWh system enters service on China Zorrilla
7. China Zorrilla (ship) reference entry
8. Riviera: P&O Ferries takes delivery of P&O Pioneer
9. ABB: ForSea completes conversion of battery ferries
10. Northvolt: Hybrid and battery ferries at Stena Line
11. CharIN: Electrification of the marine sector
12. CharIN: AC or DC charging for marine vessels
13. ISO: IEC/IEEE 80005-3:2025 Low voltage shore connection systems
14. SAE J3271_202503 Megawatt Charging System for Electric Vehicles
15. Sustainable Ships: Damen's Sparky full electric tug
16. Maritime Executive: Ampere in operation (charging time, shore buffers)
17. Siemens: Electric operation study, Norway ferries (2015)

Figures are checked against the regulation text and official sources listed above. Spotted something out of date? Write to media@dtfconference.com.