A ship at berth with her generators running is a diesel power plant in the middle of a harbour. Shore power replaces that combustion with a cable from the shore. The idea is old — navies called it cold ironing — but it is now the centre of at-berth emissions regulation from California to China, and the subject of firm European deadlines. This is the overview; our regional guides cover the individual ports in detail.
We deliver these retrofits for owners trading internationally, so this piece sets out the problem shore power solves, the standard that makes a connection portable, the regulatory map region by region, and how the work is actually run against a global trading pattern.
What problem does shore power solve at berth?
It removes the emissions a vessel produces while moored. Alongside, a ship still needs power for cargo handling, refrigerated cargo, pumps, heating and hotel services, and it normally makes that power with auxiliary diesel generators running at part load — the least efficient, dirtiest point in their range. Those emissions are concentrated exactly where people live and work, which is why at-berth air quality attracts regulation ahead of emissions at sea.
The framework sits on top of the wider decarbonisation regime. MARPOL Annex VI governs air emissions — NOx, SOx and particulate matter — from ships, and the IMO's 2023 revised GHG strategy sets the trajectory: net-zero emissions from international shipping by or around 2050, with interim checkpoints of a 20% reduction, striving for 30%, by 2030 against a 2008 baseline. Cutting auxiliary running hours at berth is one of the few measures that answers both the local air-quality problem and the carbon target at once.
What is Alternative Maritime Power (AMP)?
Alternative Maritime Power (AMP) is the supply of electricity to a ship from the shore so she can stop her auxiliary engines while at berth. The same thing is called onshore power supply (OPS), cold ironing, shore-side electricity or simply shore power. A cable from a quayside connection point feeds the ship's inlet, through a shore-connection switchboard and, on most commercial vessels, a step-down transformer, into the main switchboard that normally carries the generators.
The connection is defined by the IEC/IEEE/ISO 80005 standard family: 80005-1 covers high-voltage shore connection (HVSC) for larger vessels, typically at 6.6 kV or 11 kV; 80005-3 covers low-voltage arrangements for smaller ones; and 80005-2 covers the communication and control interface between ship and shore. Because those documents specify the interface itself, a ship built to them and a quay built to them can connect regardless of who installed either side.
Why does one standard let a ship plug in across different ports?
Because the interface is specified internationally, the ship-side equipment does not have to be rebuilt for each country. The inlet, the shore-connection switchboard, the transformer and the protection are designed to IEC/IEEE/ISO 80005-1, so the same installation meets a quay in Rotterdam, Shanghai or Los Angeles that is built to the same standard. The regional variation is in the infrastructure timetable and the paperwork, not the plug.
The one genuine electrical variable is frequency. Much of the world fleet runs at 60 Hz while a large share of European shore supply is 50 Hz, so where a vessel and her regular ports do not match, a frequency converter has to sit in the chain — on the quay where the port has provided one, on board where it has not. That decision is resolved early because it changes the on-board scope, the weight and the space demand substantially. It is a variable to be sized, not a barrier.
Where is shore power regulated around the world?
The obligations differ sharply by region, and a vessel's trading pattern determines which clock matters. The compact map:
- European Union: under FuelEU Maritime (Regulation 2023/1805, in force from 2025), containerships and passenger ships must use onshore power supply at TEN-T core ports from 1 January 2030, with the AFIR obliging those ports to provide it
- China: a mature regime — since 1 July 2019, ships fitted with shore-power capability (tankers aside) must connect when berthing beyond set durations in the coastal and inland emission-control areas where supply exists
- India: the Harit Sagar green-port guidelines of 2023 direct the major ports toward shore-to-ship power in phases, within the wider Maritime Amrit Kaal Vision 2047
- The Gulf: no single mandate yet, but rapid port modernisation across the UAE and Saudi Arabia is bringing shore-power capability into new terminal projects
- The Americas: California's CARB At-Berth regulation is the long-standing benchmark — first adopted in 2007, tightened in 2020 and extended to new vessel categories — while Brazil and the wider region are at an earlier, emerging stage
California's rule is worth singling out because it predates the European deadlines by more than a decade and shows the model works at scale: regulated container, cruise and, increasingly, tanker and vehicle-carrier calls at the state's ports must either connect to shore power or capture their at-berth emissions with an approved control technology.
How does Orion deliver a shore-power retrofit internationally?
By treating the vessel's trading pattern, not a single port, as the design input. We survey the ship against the berths she actually calls — the load she draws alongside, the frequencies she meets, the cable handling each terminal offers — and scope a connection that works across that whole rotation rather than one country. The engineering core is the same class-approved modification each time; the surrounding decisions are what we tailor to the trade.
Delivering at a distance is a scheduling discipline. The long-lead items — transformer, frequency converter, high-voltage cable — carry procurement times that must be ordered against the dock date, not the survey date, or they become the critical path. Where it saves cost we split the scope: routing, foundations and preparation done with the vessel trading under a riding crew, and only the hull penetrations, heavy lifts and final switchboard tie-in reserved for a short dock window. The class-approval path — drawings submitted and accepted before the work — runs in parallel from the start, and the retrofit can be executed at the owner's chosen yard or ours.
Frequently asked questions
- Is AMP the same as cold ironing and OPS?
- Yes. Alternative Maritime Power (AMP), onshore power supply (OPS), cold ironing and shore-side electricity all describe the same thing: supplying a berthed ship with electricity from the shore so her auxiliary engines can be switched off. The terms vary by region and specification, but the function and the underlying 80005 standard are identical.
- What is the 80005 standard for shore power?
- IEC/IEEE/ISO 80005 is the international standard family for shore connection. Part 1 covers high-voltage shore connection for larger vessels, typically at 6.6 kV or 11 kV; part 3 covers low-voltage connection for smaller ships; and part 2 covers the communication interface between ship and shore. Designing to it is what lets a ship and a quay from different suppliers connect safely.
- Do all ports run at the same voltage and frequency?
- No. Voltage varies and, more importantly, frequency splits between 50 Hz and 60 Hz across regions. A large part of the world fleet is 60 Hz while much of Europe's shore supply is 50 Hz. Where a vessel and her ports differ, a frequency converter is placed either on the quay or on board — a sizing decision resolved early because it drives on-board space and weight.
- Which shore-power deadline applies to my ship first?
- It depends on where she trades. A vessel on European container or passenger routes faces the FuelEU Maritime obligation from 1 January 2030; one calling California meets the CARB At-Berth rule already; one on Chinese coastal runs meets the 2019 requirement now. Because all are built on the same 80005 connection, a single well-designed retrofit can satisfy them together.