Environmental concerns to drive cleaner shipping

Shipping has always been central to human economic activity. It has many benefits, but also a major drawback: a significant adverse environmental impact owing to its use of oil-based fuels. Major changes are underway to first reduce, then totally eliminate this negative aspect.

The Ulstein SX190 Zero Emission offshore construction support ship (Photo: Ulstein)

This can be achieved through the introduction of other energy sources and more electric-based systems on board ships. IEC standardization work carried out by a number of IEC Technical Committees (TCs) is set to play a key role in the transition to cleaner shipping.

Shipping – the backbone of world trade

Shipping has always been essential to international trade, now more than ever before. It handles about 80 per cent of the volume and 70 per cent of the value of international trade. It allows countries to access the raw materials they need, enables the production, import and export of goods and products, and the transport of passengers.

The total value of the annual world shipping trade reached more than 14 000 billion dollars in 2019. Over 6 100 container ships are currently in service, in addition to tankers and bulk carriers.

Considering the very large volume of goods transported, made possible by the size of modern ships, the environmental footprint of shipping on a per-tonne basis is much lower than that of road transport or aviation. CO2 emissions per tonne-km from international shipping vary between three and about eight grammes, depending on the type of ship, compared to 86 grammes for trucks and 435 grammes for air transport. However, the volume of emissions from shipping is still very significant.

CO2 emissions are not the only problem. Ships burn a wide range of fuel oils and emit toxic substances, such as sulphur oxide (SOx) and particulate matter, which have a major adverse health impact in particular on populations living close to ports and coasts.

Sulphur oxide (SOx) emissions have been significantly cut in recent years through the installation of exhaust gas cleaning systems, so-called “scrubbers”. Additionally, ships increasingly use low sulphur marine diesel oil as mandated by the International Maritime Organization (IMO), the International Convention for the Prevention of Pollution from Ships (MARPOL), and recommendations from its Marine Environment Protection Committee (MEPC).

Need to accelerate transition to zero-carbon fuels and propulsion

In October 2020, the MEPC approved mandatory new regulations to cut the carbon intensity of international shipping by 40 percent by 2030 compared to 2008.

This can be achieved through greater use of electrical systems in ships, including for propulsion, of alternative fuels and with the electrification of ports' infrastructure.

Electric propulsion for ships, which has been used on waterways since the 1880s, was installed primarily in small boats transporting a limited number of passengers on rivers or lakes. In recent years it has been gradually introduced for ferry services over relatively short distances, a move that is gathering pace. In Norway, the Ampere ferry, introduced in May 2015, can transport up to 120 cars and 360 passengers, crossing a six kilometer stretch of water 34 times a day. Her lithium-ion batteries are recharged in 10 minutes at each end. A conventional ferry travelling the same route would burn a million litres of diesel fuel each year, emitting nearly 2 700 tonnes of CO2 and tonnes of SOx in the process. Norway, with more than 100 ferry lines for short routes, is likely to adopt more full-electric or hybrid electric vessels, including for fishing boats, such as the Karoline.

In Stockholm, Movitz, a boat retrofitted with nickel-metal-hybrid (NiMH) that can carry 100 passengers and can be recharged in 10 minutes, was put in service in the summer of 2019.

International Standards for secondary batteries, such as those used in these boats, are developed by IEC TC 21: Secondary cells and batteries.

However, in 2019 a fire and subsequent explosion of batteries on board the Norwegian hybrid car ferry Ytteroeyningen highlighted some safety risks from large battery installations on board ships and led to new guidelines for better safety requirements. The work of IEC TC 21 Working Group 8 includes safety standards for batteries and battery installations.

Alternative cleaner power sources for shipping

For larger ships, solutions being introduced include the use of alternative fuels, such as ammonia and hydrogen fuel cells. They produce electricity to power propulsion and ships electrical systems. Other solutions envisaged include onboard hybrid systems with hydrogen fuel cells operating alongside batteries or conventional diesel-electric systems.

In the longer-term, fuel cells are set to occupy an important place in shipping. IEC TC 105: Fuel cell technologies, develops standards and specifications for fuel cell systems [currently using mainly hydrogen, but also ammonia] already deployed in road and railways transportation systems, and for other applications.

Ammonia can also be used in solid oxide fuel cells (SOFC) to produce electricity. Standards for SOFC are also developed by IEC TC 105.

In ports, the introduction of high voltage shore connection (hvsc) systems to provide power to docked ships, is seen as a major development to cut emissions from ships which normally would use their internal diesel-fuelled engines to produce on-board power. Details on HVSC are available in IEC/ISO/IEEE 80005-1:2019, a standard developed by IEC TC 18: Electrical installations of ships and of mobile and fixed offshore units, in cooperation with ISO and the IEEE (Institute of Electrical and Electronics Engineers).

IEC TC 18 developed IEC 60092-302-2:2019, Low voltage switchgear and controlgear assemblies – Marine power.

Contacted by e-tech, IEC TC 18 Secretary Arild Roed said that the TC was looking at the inclusion of additional "necessary requirements for the maritime environment" in Edition 2.0 of IEC 62619 being currently developed by IEC SC 21/A. Besides, Roed added, "Other requirements are developed for the battery room where the battery system is to be installed," most likely considering lessons learned from the 2019 fire and subsequent explosion of batteries on the hybrid car ferry Ytteroeyningen.

Retrofitting or designing ships around fuel cells?

Ships are built to last. While retrofitting smaller vessels can be a solution, retrofitting large ships, designed years or decades ago, with battery, hybrid systems or fuel cells is not always feasible or too costly. Here, a partial replacement of onboard systems with more energy-efficient ones, powered by fuel cells for example, may be the answer.

For instance, the Dutch Future Proof Shipping company is retrofitting the 110-metre inland container vessel MSC Maas, by removing her internal combustion engines, then installing a new zero-emissions propulsion system with 825-kW fuel cells, 504-kWh batteries, electric motor and hydrogen storage. MSC Maas is set to start operating in the second half of 2021 between the Netherlands and Belgium. The vessel's new propulsion system is expected to reduce yearly CO2 emissions by approximately 2 000 tonnes, through the use of green hydrogen instead of marine gasoil.

The company is also developing a hydrogen power-barge concept to supply power to vessels in ports, as a mobile and flexible alternative to costly fixed HVSC installations.

In the long-term, designing vessels around fuel cells is another solution, with several projects underway, including for container ships and offshore construction support ships.

The Danish international shipping and logistics company DFDS is considering a fleet of hydrogen-powered roll-on/roll-off (RoRo) ferries to come into operation during the next two decades as part of its strategy to be carbon neutral by 2050. DFDS has also launched a project to introduce a large 1 800-passenger hydrogen fuel cell-powered ferry for a key route between Denmark and Norway by 2027.

To achieve zero emissions, hydrogen used in fuel cells will have to be so-called "blue hydrogen", produced using renewable sources, such as hydropower, solar or wind. Standards for these are being developed by several IEC TCs.

IEC standardization work plays a key role in the whole chain leading to cleaner, "green" shipping.