According to the International Maritime Organization, shipping was responsible for over 1 billion tonnes of carbon dioxide emissions in 2018. A significant share of those emissions came from seaport activities, including ship berthing, cargo handling, and transportation within port areas. In response, governments, NGOs, and environmental watchdog groups are sounding alarms and advocating for urgent measures to mitigate pollution at the world’s ports.

One of the most promising solutions for the decarbonization of port operations involves electrifying these facilities. This plan envisions ships plugging into dockside electric power rather than running their diesel-powered auxiliary generators for lighting, cargo handling, heating and cooling, accommodation, and onboard electronics. It would also call for replacing diesel-powered cranes, forklifts, and trucks that move massive shipping containers from ship to shore with battery-powered alternatives.

To delve deeper into this transformative approach, IEEE Spectrum recently spoke with John Prousalidis, a leading advocate for seaport electrification. Prousalidis, a professor of marine electrical engineering at the National Technical University of Athens, has played a pivotal role in developing standards for seaport electrification through his involvement with the IEEE, the International Electrical Commission (IEC), and the International Organization for Standardization (ISO). As vice-chair of the IEEE Marine Power Systems Coordinating Committee, he has been instrumental in advancing these ideas. Last year, Prousalidis co-authored a key paper titled “Holistic Energy Transformation of Ports: The Proteus Plan” in IEEE Electrification Magazine. In the paper, Prousalidis and his co-authors outlined their comprehensive vision for the future of port operations. The main points of the Proteus plan have been integrated in the policy document on Smart and Sustainable Ports coordinated by Prousalidis within the European Public Policy Committee Working Group on Energy; the policy document was approved in July 2024 by the IEEE Global Policy Committee.

Professor John ProusalidisJohn Prousalidis

What exactly is “cold ironing?”

John Prousalidis: Cold ironing involves shutting down a ship’s propulsion and auxiliary engines while at port, and instead, using electricity from shore to power onboard systems like air conditioning, cargo handling equipment, kitchens, and lighting. This reduces emissions because electricity from the grid, especially from renewable sources, is more environmentally friendly than burning diesel fuel on site. The technical challenges include matching the ship’s voltage and frequency with that of the local grid, which, in general, varies globally, while tackling grounding issues to protect against short circuits.

IEEE, along with IEC and ISO, have developed a joint standard, 80005, which is a series of three different standards for high-voltage and low-voltage connection. It is perhaps (along with Wi-Fi, the standard for wireless communication) the “hottest” standard because all governmental bodies tend to make laws stipulating that this is the standard that all ports need to follow to supply power to ships.

How broad has adoption of this standard been?

Prousalidis: The European Union has mandated full compliance by January 1, 2030. In the United States, California led the way with similar measures in 2010. This aggressive remediation via electrification is now being adopted globally, with support from the International Maritime Organization.

Let’s talk about another interesting idea that’s part of the plan: regenerative braking on cranes. How does that work?

Prousalidis: When lowering shipping containers, cranes in regenerative braking mode convert the kinetic energy into electric charge instead of wasting it as heat. Just like when an electric vehicle is coming to a stop, the energy can be fed back into the crane’s battery, potentially saving up to 50 percent in energy costs—though a conservative estimate would be around 20 percent.

What are the estimated upfront costs for implementing cold ironing at, say, the Port of Los Angeles, which is the largest port in the United States?

Prousalidis: The cost for a turnkey solution is approximately US $1.7 million per megawatt, covering grid upgrades, infrastructure, and equipment. A rough estimate using some established rules of thumb would be about $300 million. The electrification process at that port has already begun. There are, as far as I know, about 60 or more electrical connection points for ships at berths there.

How significant would the carbon reduction from present levels be if there were complete electrification with renewable energy at the world’s 10 biggest and busiest ports?

Prousalidis: If ports fully electrify using renewable energy, the European Union’s policy could achieve a 100-percent reduction in ship emissions in the port areas. According to the IMO’s approach, which considers the energy mix of each country, it could lead to a 60-percent reduction. This significant emission reduction means lower emissions of CO₂, nitrogen oxides, sulfur oxides, and particulate matter, thus reducing shipping’s contribution to global warming and lowering health risks in nearby population centers.

If all goes according to plan, and every country with port operations goes full bore toward electrification, how long do you think it will realistically take to completely decarbonize that aspect of shipping?

Prousalidis: As I said, the European Union is targeting full port electrification by 1 January 2030. However, with around 600 to 700 ports in Europe alone, and the need for grid upgrades, delays are possible. Despite this, we should focus on meeting the 2030 deadline rather than anticipating extensions. This recalls the words of Gemini and Apollo pioneer astronaut, Alan Shepard, when he explained the difference between a test pilot and a normal professional pilot: “Suppose each of them had 10 seconds before crashing. The conventional pilot would think, In 10 seconds I’m going to die. The test pilot would say to himself, I’ve got 10 seconds to save myself and save the craft.” The point is that, in a critical situation like the fight against global warming, we should focus on the time we have to solve the problem, not on what happens after time runs out. But humanity doesn’t have an eject button to press if we don’t make every effort to avoid the detrimental consequences that will come with failure of the “save the planet” projects.