UCL Energy Institute


Green hydrogen is the best option to transition the shipping industry away from fossil fuels

19 April 2022

New report launched by Ocean Conservancy and its partners at UCL Energy Institute's UMAS considers alternative fuels to get the sector closer to Net Zero.

Freight ship heading out to see from docks

A new report, titled “Future Maritime Fuels in the USA – the options and their potential pathways” discusses what alternative shipping fuels are already available and what a U.S. transition to those fuels would look like.

This follows another report launched earlier in the week that discusses the scale of emissions and potential for decarbonizing the U.S. flagged fleet.

To avert the direst consequences of climate change we need to rapidly decarbonize the global economy. In most cases, electrification and renewable energy sources present the best path forward. However, for bulk shipping across our ocean, which is responsible for 3% of global emissions and poised to grow, zero-emission fuels coupled with energy saving devices is the best path to decarbonization.

Daniel Hubbell, shipping emissions campaign manager for Ocean Conservancy, said:

The United States is primed to lead the lead the way in the transition to green fuels for the maritime sector. Producing green hydrogen-based fuels can kickstart the transition to new shipping fuels along promising green corridor routes within the U.S. and can make key down payments that will drive further investments in renewable energy and feed the demand for climate action within the global transportation sector.”

Hydrogen and ammonia are two fuels that both have the potential to power shipping vessels while emitting zero greenhouse gases, but when evaluated across their entire lifecycle of emissions, green hydrogen is the only option that can achieve the emissions reduction targets set forth in the Paris Agreement. Green hydrogen fuel is produced by splitting water molecules into hydrogen using renewable energy. 

Other forms of hydrogen fuels, such as grey, blue or brown, rely on a mixture of fossil fuels and hydrogen that will continue to emit carbon dioxide and uphold fossil fuel infrastructure. Currently, existing grey and brown hydrogen production methods emit the same amount of carbon dioxide as about one third of the European Union. Methane leakage throughout the production process is another reason for concern when producing grey or blue hydrogen because of its potency as a greenhouse gas – it’s 81 times more efficient at warming our atmosphere over a 20-year period than carbon dioxide is. Relying on carbon capture technologies to reduce the greenhouse gas emissions generated by the production of these types of hydrogen will require huge investments and the technology is not yet capable of capturing carbon dioxide efficiently enough.

Joe Taylor, Consultant at UMAS and lead author of the report said: 

The forthcoming decade is crucial for the US to initiate the transition to Scalable Zero Emission Fuels (SZEF) in the maritime sector and become a leader in the global shift away from fossil fuels. To fulfil the ambitious targets set by the new administration, the Department of Energy must revise its hydrogen strategy and put a far greater emphasis on green hydrogen production, coupled with an extensive expansion of renewable energy capacity.”

The U.S. government is poised to lead the international shipping industry away from fossil fuels and towards green hydrogen. Already, the U.S. government has committed to helping the industry achieve zero emissions by 2050 and taken up leaderships on key global initiatives to adopt the use of zero-emission fuels including Mission Innovation, the Clydebank Declaration and the First Movers Coalition. Domestically, the U.S. already has the technology expertise and energy infrastructure that make it well suited to adopt zero-emission fuels along shipping routes on both the east and west coasts of the country.

Transitioning the shipping industry to zero-emission fuels, notably green hydrogen, needs to happen as rapidly as possible and will require both financial and strategic support from the U.S. government. The government must rethink the Department of Energy’s hydrogen program plan, increase its renewable energy production, and take advantage of the existing domestic and regional shipping routes – which account for 10% of shipping’s total fuel consumption – that are already ideal for transitioning this decade.