Following the UK Supreme Court’s landmark ruling that makes downstream emissions legally mandatory in Environmental Impact Assessments (EIAs), ports are now under greater scrutiny to measure and mitigate the emissions generated not just within their boundaries, but across the entire supply chain (scope 3).
Ships at berth are among the largest contributors to port-related emissions, often running diesel generators for power. These emissions, rich in CO2, NOx, SOx and particulate matter, fall squarely under Scope 3. However, many ports still lack the infrastructure to offer shore power across all berths, leaving a gaping hole in their ESG reporting and sustainability strategies.
Against this backdrop, ports are exploring how to electrify more berths in a way that is fast, affordable, and flexible.
The limits of fixed shore power outlets
Historically, shore power has relied on fixed sockets embedded along the quayside. Whilst, in theory, these offer broad berth coverage, in practice, the variation and size of modern vessels make alignment a major hurdle.
Shore power – supplying ships with grid electricity so they can shut down their engines and reduce emissions – has been established for years in regions such as California. Demand has been accelerated by three key drivers:
1. Health concerns related to smog and particulates polluting the densely populated surrounding areas
2. Internal company net zero targets
3. Local government decarbonisation mandates
However, inconsistent global standards, varied ship connector locations, and heavy, hard-to-handle cables have limited broader uptake of shore power.
As container ships, cruise vessels and Ro-Ro ferries have grown in size, the locations of their high-voltage connectors have shifted. A berth designed for one generation of vessels may not align with the next, requiring numerous fixed connection points on both port and starboard sides.
Berths frequently accommodate multiple ship types and sizes. A quay section might receive two large container vessels one day and three smaller feeders the next. Fixed sockets cannot respond to this variability. Furthermore, port operators face worker-safety concerns when heavy cables – sometimes weighing up to 20kg per metre – must be manually handled to bridge alignment gaps.
The cumulative effect is significant: a berth that, on paper, offers 30 percent theoretical shore-power coverage may deliver less than three percent in practice.
Mobile shore power: The solution?
In response to the limitations of fixed infrastructure, igus UK has developed a mobile, self-propelled socket system. Compliant with IEC 80005-1 and the EU Machinery Directive, the igus Mobile Shore Power Outlet (iMSPO) delivers medium-voltage shore power directly to the vessel (whether container, cruise, ferry or Ro-Ro), regardless of its mooring position.
Installed above the fender system and controlled remotely, the iMSPO can travel in excess of 400m along the quay, ensuring full berth coverage without the need for multiple fixed installations. This results in zero dead spots where the vessels cannot connect.
The move toward whole-berth coverage
One of the most attractive aspects of the mobile approach is its ability to replace several fixed outlets with a single, travel-capable unit.
igus recently conducted a study in the US which suggested that the cost of installing a single cable, with all the civil engineering works, cabling and switchgear involved, could reach up to $2 million.
Meanwhile, with a mobile system such as igus’s, ports simply need one transformer station, one supply point, and one investment for a future-proof solution. This significantly improves operational efficiency, accelerates return on investment, and gives ports the ability to shut down shipboard diesel generators, cutting emissions at the source.
More than a dozen iMSPO systems are already in operation worldwide, with deployment expected to double by the end of the year. While questions remain around long-term integration across mixed-vessel berths, the increasing interest in mobile shore power reflects a wider recognition that modular, standards-compliant solutions may offer the fastest path to widespread electrification.
In the end, mobile shore power is about more than simply meeting new standards or ticking the required ESG boxes. Engineers need to make electrification workable in the real world. Mobile systems like the iMSPO are not a silver bullet, but they offer a flexible, practical way to make shore power available where it’s needed most – and empower ports to sail towards net zero.