The International Maritime Organization has set a net-zero goal “by or around 2050”. What is needed to reach this?

At a UN summit, countries have agreed to curb shipping emissions to net zero “by or around 2050”.

At the annual meeting of the International Maritime Organization (IMO), countries agreed to cut emissions by 20% by 2030 and 70% by 2040, compared to 2008 levels, and 100% by or around 2050. Small island nations and richer countries had called for a 50% reduction by 2030 and 96% by 2040.

IMO Secretary-General Kitack Lim described the agreement as “a landmark development that opens a new chapter in decarbonisation at sea”. But campaigners warn the deal is flawed and will not allow the shipping industry to meet the Paris Agreement’s goal of limiting global temperature rise to 1.5 degrees Celsius by the end of the century.

Shipping is a highly polluting industry, responsible for nearly 3% of global emissions and generating around one billion tonnes of greenhouse gases each year – roughly the same amount as Germany’s carbon footprint. If it were a country, the shipping industry would be the sixth largest polluter in the world.

Reducing maritime emissions rapidly in the next three decades will require new regulations, infrastructure and fuels. But what might green shipping of the future look like?

Wind-powered ships

The shipping industry can reduce its reliance on fossil fuels by turning to an ancient technology: sails. Wind propulsion is considered one of the most promising energy sources available for the  rapid decarbonisation of shipping. Swedish company Oceanbird has built a prototype ship with four rigid sails. Wind power not only propels the ship forward but also aids its manoeuvrability and agility on the water. One of the biggest challenges is encouraging governments and investors to adopt wind propulsion and retrofit ships, while wind propulsion is still early-stage.

Hydrogen fuel Battery

Deploying clean fuels such as hydrogen is critical if the shipping industry is to reach net zero by 2050. Green hydrogen – generated by using renewable energy, such as wind or solar power, to extract hydrogen from water molecules – is emissions-free. But there are some major challenges when deploying hydrogen: the fuel must be stored at cryogenic temperatures of -253C (-423F) and crew must be trained how to handle it as the fuel is highly flammable.

A hydrogen fuel cell is a device that uses hydrogen as fuel and generates electricity by reacting with oxygen. It belongs to a renewable energy technology and is considered as a clean, efficient and environmentally friendly energy solution.

The working principle of hydrogen fuel cells is based on the electrochemical reaction of hydrogen and oxygen to generate electricity and water. In a hydrogen fuel cell, hydrogen gas passes as fuel through the anode, oxygen from the air passes through the cathode, and the two react in an electrolyte membrane (usually a polymer electrolyte membrane). In the electrolyte membrane, protons (H+) of hydrogen gas are conducted to the cathode through the electrolyte membrane, while electrons flow back to the anode through an external circuit, completing the current loop. At the cathode, the protons and electrons react with oxygen to form water, releasing electricity.

The main advantages of hydrogen fuel cells include high energy density, zero emissions (only water is produced), convenient fuel supply and fast filling, long-term stable operation, etc. They are widely used in fields such as transportation, energy storage, mobile devices, and backup power.

Although hydrogen fuel cells have many advantages, they still face some challenges in practical applications, such as the cost of hydrogen production and storage, the construction of hydrogen supply infrastructure, etc. With the development and advancement of technology, hydrogen fuel cells have great potential as a clean and sustainable energy solution.



Maersk, the world’s second-largest container shipping company, is betting big on green methanol to help it decarbonise. The company has ordered a total of 25 methanol-powered ships to date. Green methanol is a low-carbon fuel which can be produced from sustainable biomass or by using renewable electricity to split water into oxygen and hydrogen, which is combined with carbon dioxide. Unlike hydrogen, green methanol does not have to be stored under pressure or extreme cold, and many ports already have infrastructure in place to store the fuel. But the process is complex:  CO2 must be captured out of the atmosphere, technology which is still emerging, expensive and as yet unproven.

Electric boats

Batteries charged using renewable electricity are another way to curb shipping emissions. But there are limits to the distances they can power. Currently, renewable batteries are an option only for smaller ships making short journeys, such as ferries and river boats, not for large cargo ships crossing oceans. Instead, ship owners are looking to power cargo ships with a combination of wind power and solar panels. Japanese renewable energy systems company Eco Marine Power, for example, has developed “EnergySails”: rigid sails fitted with solar panels, which allow ships to use both solar and wind energy at the same time.

An electric ship refers to a ship driven by electricity as a power source. Compared with traditional ships that use internal combustion engines, electric ships use electric motors or electric propulsion systems to propel the ship forward. They typically use energy storage devices such as battery packs, fuel cells, or supercapacitors to store electricity and supply it to electric motors through the power system.

Electric ships have several advantages. First, they are zero-emission, since electric ships produce no direct tailpipe emissions and are environmentally friendly. Second, electric ships are less noisy, reducing noise pollution. In addition, electric ships are relatively inexpensive to operate, especially in regions where electricity costs are low or renewable energy supplies are plentiful.

Electric boats are used in a wide range of applications, including personal recreational watercraft, pleasure boats, ferries, patrol boats, cargo ships, and more. In addition, electric ships can also be used in water protection, environmental protection of lakes and rivers, scientific research and other fields.

However, electric ships also face some challenges. The further development of battery technology, the construction of charging facilities, the improvement of endurance and the reduction of cost are the key factors for the development of electric ships. With the continuous advancement of technology and increasing environmental awareness, electric ships are expected to play an important role in the future shipping industry.


Green infrastructure

A rapid uptake of green fuels on vessels will require abundant new infrastructure at ports to produce and store them, and to allow ships to refuel. Ports must invest in hydrogen-generating electrolysers, renewable energy capacity, such as wind and solar power, as well as battery and hydrogen storage facilities.  Most ships will also need to be retrofitted to enable them to run on green fuels, use wind propulsion and digital software to improve their efficiency and optimise routes.


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