The International Maritime Organization (IMO) has agreed to consider development of new safety provisions for cold ironing as well as non-mandatory guidance on safe operation of the associated services in port.

According to BIMCO, the guidelines will help ensure the safety of the people involved and compatibility between ship and shoreside power systems on a global basis.

The new framework will be considered at the IMO sub-committee meeting on Ship Systems and Equipment (SSE 6), which is held in London on 4-8 March 2019.

On-shore power supply (OPS) - also called cold ironing - provides shoreside electrical power to ships at berth, enabling it to turn off auxiliary engines.

The concept of cold ironing has gained attraction to become an effective short-term measure for lowering the greenhouse gas emissions from ships.

The few ships operating on a long-term permanent trade between the same ports may benefit from having cold ironing as a sustainable energy solution at berth, but it requires that the power supply originates from renewable energy sources.

Cold ironing – not currently a sustainable solution
While BIMCO welcomes the guidelines, cold ironing calls for substantial investments both ashore and on board. BIMCO therefore calls for caution on whether this is cost beneficial for ships that do not operate on long-term permanent trade.

Furthermore, since the main part of the on-shore power supply comes from combustible fuels and since the proportion of coal used for electrical consumption ashore is not on the decrease, BIMCO does not currently consider cold ironing to be a sustainable technical solution for ships in global trade. The International Energy Agency states that power generation from combustible fossil fuels accounted for around 67 per cent of the world’s total gross electricity consumption in 2016.

If the ship and the power plant ashore both use fuel, the same amount of GHG will be emitted regardless of whether it is generated on board or ashore. But if the power plant ashore uses coal, the GHG emissions will be even larger by using OPS.

Therefore, OPS will only contribute to a relative reduction of greenhouse gasses emissions if the power plant ashore is using nuclear power or renewable energy.

Furthermore, a number of operational matters need to be taken into consideration before the concept can be considered for global implementation:

• Cost effectiveness in using shore power vs onboard generators
• Incompatibility and lack of using uniform standards (voltage and frequency)
• Lack of implementation of common international IEC and ISO standards
• Practical handling of cables and connections
• Absence of prevention of excessive load to shore power grid
• Waiting time for connecting and disconnecting on-shore power leading to prolonged port stay
• The price of shore power and transparency in price setting

Cold ironing is a term that first came into use when all ships had coal-fired engines. When a ship was moored alongside, there was no need to continue feeding the fire and the iron engines would literally cool down, eventually going completely cold. Hence the term cold ironing.