If all ships were fitted with the capacity to connect to grid-generated shore power when at berth, there would be gains all round. “Cold ironing”, a term for shore power, is good for human health, the environment, and business.
Shore power for a healthier environment and business
How much of a health hazard is international shipping pollution?
The international shipping industry is currently estimated to account for up to 5% of world carbon emissions. That share could be 25% by 2050 – a significant contribution to climate change.
The main reason is the fuel that ships burn – low-grade fuel oil (or bunker oil). Its sulphur content is some 3,000 times higher than that of conventional diesel for cars. That means that cargo and cruise ships also generate very high levels of nitrogen oxide (NOx), sulphur oxide (SOx), particulate matter (PM), and volatile organic compounds (VOCs).
Most large ships keep their engines idling when they are docked to generate electricity for their onboard living systems. It is estimated that in an eight-hour stay in port, a ship can emit over 2.5 tons of pollutants. And as ports are often busy, highly populated areas, whole communities are directly affected by ships’ emissions.
How can shore power help companies and operators safeguard health and the environment?
Berthed ships that are equipped for shore connection systems do not discharge any emissions (particulate and non-particulate) – because they shut down their engines. Hence “cold ironing” – a widely used term for shore power. A shut down engine becomes a chunk of “cold iron”.
With their engines just pieces of cold iron, ships get the power they need from the local onshore electricity grid. The aggregate result, then, is shore power facilities slash NOx, SOx, and PM emissions by 90% and carbon by up to 50%. And when the smart grid eventually enables ports to harness renewables, the carbon footprint will be negligible.
How much can shore power save?
Outfitting ships for shore connection is a practical response to the moral imperative of saving lives and sparing the environment. But it also makes business sense.
Here is a quick hypothetical calculation in euros.
Based on average 2011 marine diesel fuel prices of €983/ton, electricity generated onboard by diesel engines cost €156/MWh as opposed to €120/MWh for power from the grid (Source: Schneider Electric “Intelligent Energy”)
Here’s another one in US dollars.
If a craft berthing for 24 hours in a Californian port is charged the commercial rate of $0.11 per kWh for using 1600kW shore power, it will pay US$4,200. That’s less than half the price of burning marine diesel oil. (Source: “The Economics of Cold Ironing”)
And grid-generated shore power goes easy on engines. The reduced wear and tear lengthens their life cycles.
Annual engine maintenance savings per ship have been estimated €9,600 (at maintenance costs of €1.6 per hour per engine).
Longer life cycles offset the costs of capital investment. And scalable, manageable solutions are available.