Cold Ironing

Today I want to tell you something about the reality of providing electricity to ships -be it ferries, yachts or cruise ships- and its limitations. The technology is called ‘cold ironing’ or ‘cooling the irons’. The origin of the name comes from when ships were propelled with steam engines and boilers. Upon reaching the port, the boilers were turned off and the machines (the irons) cooled down.

Cruise ships need to keep all their services active when they are in port: air conditioning; refrigerators; ventilation; lighting and other services. A tourist cruise ship whose 20% of passengers do not disembark, or a large yacht with full crew, consumes much more than a ferry. The ferry only needs to keep its basic systems turned on to a minimum while disembarking its cars and passengers until the next boarding.

To be able to ‘plug in’ a cruise ship consuming so much power would require a huge cable and would be very difficult to manipulate and connect. Internationally, the norm was adopted that in the ports, the ships will be fed with 6000 volts. To connect to that voltage, the electrical system of the ships must be prepared.

And here comes the interesting thing: cold ironing is valid only when the power it supplies has been produced in a “clean” way. To do this, the port must be close to a power plant or have generators whose emissions contaminate much less than the ship’s own generators. The aim is to reduce pollution – not generate it elsewhere.

In most cities, only 40% of the electricity produced by oil, coal or alternatives reaches the user. The rest is lost in wiring, transformers and distribution centres – Palma being one of these cases. So imagine a ferry or cruise ship plugged into land: it could generate more emissions in the power plant than if it used its own generators, as it would burn more than twice the fuel to use the same electricity.

In Marina Port Tarraco, there is a 6000 volt plant for large yachts. It has been running for several years and is mobile. Why not rent it and try it out in Palma before spending money on the ferry terminal?

Old ships pollute proportionally much more than new ones because the requirements they had to meet were more permissive. Modern cruise ships and large yachts must comply with much more demanding regulations for their emissions.

The electrical network of the Port of Palma and the Paseo Marítimo is saturated and does not admit any more load. They would not be able to efficiently connect the ferries.

The real cold ironing solution makes use of ground-based generators powered by low-emission fuel – gas or biofuels. Note: biofuel -a product of agricultural activities- generates emissions similar to those of petroleum derivatives, but guarantees its sustainability and a clean cultivation process. With an efficiency of approximately 95%, similar to those of modern ships, the much-desired pollution reduction effect is achieved, even if it is less than desired.

Modern Yachts is the least polluting fleet – the rest are smoke.

Partner and manager of two marinas in Mallorca for 15 years Oscar has been designer and consultant for  marina projects in various countries, and designer of customized marina elements. He has shared his experience through more than 30 conferences in 12 countries and has written numerous articles for Marina World and other international nautical magazines.

Oscar is a Certified Marina Professional, was founder director of the Global Marina Institute, member of ICOMIA’s Marinas Committee, member of PIANC Recreational Marine Committee,  Convenor of  ISO  TC228  WG8 “Yacht Harbours”, member of the Global Marine Business Advisers  (GMBA) group  and founding member of the Asia Pacific Superyacht Association.

Oscar Siches 

+34 667 494 85 

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