In the days of coal and steam, ships in port for long periods would allow their boilers to cool down and shut off, to reduce their fuel costs and spare longshoremen the misery of doing back-breaking labor while breathing soot. This was referred to as ‘cold ironing,’ and was a lot more straightforward with no onboard computer systems to run.
But now, whether or not a ship is moored alongside, hotel load – the electrical needs of the bridge and non-propulsion based auxiliary systems – is enormous, particularly on passenger vessels. Until recently it wasn’t possible to run these systems without burning some form of – usually expensive – diesel fuel in auxiliary generators. But shore power (its nomenclature is now regarded as interchangeable with ‘cold ironing’) is seeing uptake at various ports around the world. Vessels can connect to a cable and run their hotel loads on grid energy, switching off their fossil-fired generators in the process.
Recently, the California Air Resources Board (CARB) extended regulation compelling ships to connect to shore chargers to car carriers and tankers, as well as container, reefer and cruise vessels. Most ports around the world do not have regulations to force vessels to use shore power, but rather offer it as a cheaper alternative to burning fuel oil in onboard generators. CARB, though, reports that its regulation, originally adopted in 2007, has reduced particulate, NOx and sulfur emissions by 80%, which reduces the risk factors for many types of cancer.
A mixed bag
For shipowners, there is a case to be made for expanding shore power availability, as a retrofit is simple; many containerships, including COSCO, CMA CGM and Hapag-Lloyd vessels, now sport a containerized shore-power connector system on deck.
In the Americas, grid power is supplied at a frequency of 60Hz, the same as the internal power supply on a ship. In European countries though, grid power is supplied at a frequency of 50Hz – which means that European installations must feature a frequency converter to adapt the energy before it is used to power the ship.
Some countries could offer energy cheaper than others; Iceland and Norway have grid energy that is almost entirely comprised of renewables, and could cut CO2 from ships moored at their ports.
Meanwhile in France, abundant nuclear energy also lends itself to cheap shore power, and in September the Port of Dunkirk became the first to offer this service.
Germany, thanks to high energy costs, has a checkered relationship with shore power. But late last year, the Port of Hamburg committed to install it at the terminals of Burchardkai, Predöhlkai and Europakai, as well as its cruise terminals. This was followed by a similar announcement from the Port of Kiel, in February, which plans to provide some 16MVA for vessels at its Ostseekai and Schwendekai terminals. (A Stena vessel inaugurated the connection this month.)
Then in June, Hapag Lloyd Cruises’ vessel Europa 2 connected up at Hamburg’s Altona terminal, and consumed 2.2MW of power per hour– the equivalent of one 130m onshore wind turbine running at maximum capacity – for 30 days. Germany’s grid supply is more than a third renewable, and it was from this fraction that power was provided to Europa 2 – fortunately, not from the 22.5% of German power that comes from burning lignite. This spared some 600 tons of carbon dioxide.
A step further
If the maritime industry is to take seriously the notion of battery power, shore power becomes even more attractive. While there is almost zero chance of running deepsea commercial vessels on pure battery power before 2050, some of these ships are starting to incorporate smaller battery installations for auxiliary power purposes, such as load-levelling; leaving port with them fully charged could save a good deal of fuel while underway.
Smaller vessels, however, will see the greatest benefits. Norway is in the process of electrifying many of the passenger and RoRo ferries which network the country’s various islands; in many cases, vessels are being fitted with large energy storage systems which can handle enough charge for a whole voyage, and recharge at the terminal while offloading using shore power.
Not every country can yet offer grid energy – especially renewable energy – cheaper than the cost of ships’ fuel oil. However, as vessels strive to meet their obligations under the IMO’s 2030 and 2050 emissions targets, and new, exotic and expensive fuel types become part of the mix, this is likely to change – and fast.