When the Grimaldi shipping company’s ferry, Ciudad de Soller, berths at the Port of Barcelona on its daily trips between the city and the island of Palma in the Mediterranean, the vessel no longer has to keep its auxiliary engines running to maintain air-conditioning and other essential equipment. Since July 2024, in one of the more recent examples of shipping’s pursuit of decarbonisation, the engines are switched off while the ferry functions courtesy of shoreside power.

Often overlooked in the pursuit of maritime’s holy grail of net zero, the great ports are investing heavily in a cleaner future as the IMO urges them and shipping to work together. Apart from the provision of onshore power supply, as at the Port of Barcelona – preferably delivered from renewable sources – the ports are bunkering low- and zero-carbon fuels as they become available, running giant battery-powered cranes and flying electric drones to inspect cargoes.

Spirit of urgency 
There’s an urgency in the shipping industry. Indeed, the Port of Barcelona’s shoreside charging facility was installed six years ahead of the European Union’s (EU) mandatory deadline. The system is based on a medium-voltage network that allows ferries like the Ciudad de Soller and container ships to shut down their auxiliary engines and hook up to a 100% electrical network. The Barcelona project follows Hamburg’s example which switched on a similar system in January 2024.

According to the port’s calculations, 49 tonnes of CO₂ is saved during a container ship’s 41 hours at berth as it typically consumes 73 MWh of energy. The annual savings in CO₂ emissions add up to the equivalent of 135,000 cars driving at 30 km/h over a year.

Port authorities don’t want to stop there. In the not too distant future, the hope is to power shoreside equipment with hydrogen.

How is shipping moving to net zero? 
Under pressure from the EU and other jurisdictions, clients and its own members, just over a year ago the IMO reaffirmed its binding commitment to a steady decarbonisation of the global shipping fleet, numbering about 110,000 vessels with a gross tonnage of 1.6bn. The target the IMO set on behalf of the industry is to emit virtually no greenhouse gas (GHG) emissions ‘by or around 2050’. In the long run the express intention is for the IMO’s net-zero framework to become international law.

The shipping industry is taking this seriously. According to an August 2024 report from shipbroker Clarksons, 41% of new tonnage ordered in the first half of this year alone will be capable of running on alternative fuels. That’s 315 ships for a total of 17.3mn gross tonnes. ‘The energy transition and the changing legislation continue to shape the arrival of new tonnage,’ concludes Clarksons.

In the meantime, the IMO has established a series of milestones – ‘indicative checkpoints’ – along this challenging voyage. By 2030 ships should cut emissions by at least 20%, but preferably 30%, and rising to 70–80% by 2040. In terms of fuel the IMO is looking for a 5–10% uptake of zero-emission fuels as soon as 2030, assuming availability.

So far, so ambitious. But the IMO also introduced a series of mandatory short-term, technical measures that have provoked much debate. Shipowners must calculate their vessels’ energy efficiency under an index (EEXI) and report their operational carbon intensity on an annual basis. The Carbon Intensity Indicator (CII) rating is discussed below.

As if that’s not enough to deal with, the global fleet will soon face a series of mid-term measures currently under discussion. These relate to a phased reduction of marine fuel’s GHG intensity and a pricing mechanism for GHG emissions. The current timetable calls for these measures to be adopted in 2025 and enter into force by 2027, which doesn’t leave a lot of time.

Electrification of maritime fuelling facilities at the Port of Barcelona adds up to annual savings in CO₂ emissions equivalent to 135,000 cars driving at 30 km/h over a year. 
 

How is IMCA reducing shipping emissions? 
Many organisations are working on these in practical ways, including the International Marine Contractors Association (IMCA). Under the heading ProjectGHG, the Association says that its current activities include the standardisation of data reports of emissions, so that comparisons can be made more easily, as well as holding vessel efficiency workshops to minimise fuel use and explain ‘behavioural-based decarbonisation’ initiatives which put crew in the front line.

IMCA says: ‘Studies have shown that if crews are made aware of the energy consumption on a vessel then they instinctively find ways to reduce it through smarter, more efficient operations.’

IMCA members and energy companies are also collaborating on electrification for offshore charging, a useful technology for vessels that spend weeks or more out of port. Among other innovations, maritime charging facilities are being installed at new offshore wind farms.

The IMO’s indicative checkpoints meet the approval of the IMCA. ‘[They] provide a benchmark against which the marine contracting industry can assess its progress in the coming years,’ notes Margaret Fitzgerald, Head of Legal and Regulatory Affairs. ‘This also lays down the gauntlet to fuel manufacturers to get on with the task of producing sufficient zero and near-zero GHG fuels within the next six and a half years to meet industry demands.’

Production of cleaner fuels is important. According to the IMO’s own data, cleaner fuels should get the global shipping fleet to about 65% of the way to its 2050 net-zero target.

 In pursuit of the IMO’s 2050 goals, collaboration is seen as crucial. For instance, as Barcelona worked towards portside charging, electrification engineer Carlos Guerra and his team made frequent visits to Hamburg to share information. Guerra says: ‘This is a very new technology in Europe and we practically started from scratch.’ He expects Barcelona to pave the way for other Spanish ports.

Guerra adds that it’s a long-term exercise for any port to tool up for shoreside charging. In the long run, the supply of renewable electricity for visiting ships will require a five-fold increase in installed power. Simultaneously, the shipping industry will have to step up by fitting transformers and frequency converters that marry with the shoreside installations. In this, a cable is typically run from a small container at the stern and is plugged into electrical panels.

Sounds easy, but as Barcelona’s electrical engineers explain, the ships’ onboard energy must be carefully managed in terms of voltage and frequency in order to avoid a breakdown in the charge. Many ships are already equipped this way, in particular container ships because they have a lot of spare space. But there’s less room on ferries and cruise ships, especially in engine rooms. In some cases, the equipment has to be designed in from the start.

Also in the long run, decarbonisation will depend on retrofitting cleaner technologies, according to Clarksons’ analysis. Retrofit is already underway. No less than 8,700 vessels now use energy-saving technologies in some form or other. These range from more efficient rudders and propellers to wind power, such as Flettner rotors and wind kites.

• Further reading: ‘Is the maritime industry’s approach to GHG emissions fuzzy for future regulations?’ As shipping strives to cut greenhouse gas emissions, a raft of regulatory changes are on the horizon. But do they fudge the complex issue of maritime emissions reduction, asks Eirik Nyhus, Vice President, Director Environment, DNV, who outlines what lies ahead. 
• The Port of Huelva is assisting in the development of both alternative maritime fuels and green shipping corridors, thanks to its geographical position in the southern part of Spain. Director of the Port Authority of Huelva, Ignacio Álvarez-Ossorio Ramos, explains.