The shipping industry is looking for ways to reduce its CO2 emissions. Batteryelectric drives only offer a solution for short routes. For overseas journeys a combination of various technologies is likely to be needed.
According to the International Energy Agency IEA, in 2021 the shipping industry was responsible for around two percent of global energy-related CO2 emissions. That doesn’t sound like much but given the great importance for world trade – more than 80 percent of global trade is handled by seagoing vessels – there are predictions that shipping could account for 17 percent of total annual CO2 emissions by 2050.
Recent increases in emissions
The industry is well aware of this fact. Accordingly, the International Maritime Organization (IMO) has adopted a greenhouse gas strategy to reduce the CO2 emissions per transport work as an average across international shipping by at least 40 percent by 2030 and by 70 percent by 2050, compared to 2008 levels. However, according to the ship broker Simpson Spence & Young, the carbon dioxide emissions from global shipping increased by 4.9 percent in 2021 in comparison to the previous year and are thus higher than in 2019. According to the ship broker’s annual industry outlook, the growth in emissions in 2021 represents an “inconvenient truth” for the International Maritime Organization (IMO). This means that much more comprehensive measures are needed to steer the maritime traffic sector towards the goal of “net zero emissions by 2050”.
Electric ferries have proven themselves
However, changes are afoot in the industry, with electrification also being promoted in this sector. The world’s first large car ferry with an electric motor used for regular scheduled-service operation started running back in 2015. The “Ampere” makes the 20-minute, six-kilometre trip across the Sognefjord 34 times a day. In 2022 the electric ferry “Ellen” set a new world record by travelling over 50 nautical miles – around 92 kilometres.
“Ellen is an excellent example of the future for electric transport. It’s cleaner, greener and more efficient than her fossil fuel competitors. Electrifying maritime transport is a clear-cut way to reduce greenhouse gas emissions,” says Kimmo Rauma, Vice President, Danfoss Editron.
The company provided the drivetrains and drive motors for the ferry. Cargo ships are also experimenting with electric motors. As one example, at the end of 2021 the “Yara Birkeland” was put into operation. The 80-metre-long container ship transports fertiliser from the Yara factory in Porsgrunn via inland waterways to the seaports of Larvik and Brevik, a journey of 31 nautical miles. To cover this distance, the “Yara Birkeland” is equipped with a battery capacity of 6.8 megawatt hours. “It will cut 1,000 tonnes of CO2 and replace 40,000 trips by diesel-powered trucks a year,” says Svein Tore Holsether, CEO of Yara.
Hydrogen as an alternative
However, battery-electric drives reach their limits in sea-faring vessels due to their limited range. Green hydrogen could therefore play an important role in the decarbonisation of the shipping industry, with regard to its potential to pioneer synthetic fuels as well as its direct use as a marine fuel. As a result, the DNV – the maritime industry’s leading global classification society – issued the Norwegian technology supplier HAV Group ASA provisional approval for their hydrogen-based energy system.
The system uses liquid hydrogen storage tanks and fuel cells and is designed to be retrofitted to two coastal cruise liners belonging to the shipping company Havila Kystruten. The concept ship “NYK Super Eco Ship 2050” – a car and lorry transporter – is also planning a drive system with hydrogen-powered fuel cells. In addition, a special hull is expected to reduce the energy demand by 70 percent as it weighs less and will reduce water friction using expelled air bubbles.
Methanol as a readily available solution
In contrast, Maersk is focussing on green methanol: “Green methanol is the best scalable green fuel solution for this decade, and we are excited to see several other shipowners choosing this path. It adds further momentum to the rapid scaling of availability needed to bring down the premium on green methanol and accelerate the evolution of climate neutral shipping,” says Palle Laursen, Chief Fleet & Technical Officer at Maersk.
The shipping company has already ordered 19 container ships which run on the green fuel and is currently securing the necessary production capacity with various manufacturers. Maersk is aiming to procure at least 730,000 tonnes of green methanol per year by the end of 2025.
Back to the roots
However, the shipping industry is also returning to a very traditional propulsion system: the sail – admittedly a more high-tech version. Take the planned “Orcelle Wind”, for example – in principle its sails are just vertical aircraft wings. They will be made from composite materials and controlled by a computer. Such “wing sails” generate more power, are more sturdy and are easier to control than their conventional counterpart.
The “Orcelle Wind” is being developed by the shipping company Wallenius Wilhelmsen and is a fully fledged roll-on/roll-off ship capable of transporting 7,000 cars and producing up to 90 percent fewer emissions than other ships. With a length of 220 metres and a height of around 100 metres up to the top of the sail, it will be the largest sailing ship in the world. If everything goes according to plan, the “Orcelle Wind” could be put into service in 2026.
17 percent of global CO2 emissions could be caused by shipping in 2050.
Source: S&P Global
