Can Commercial Shipping achieve net zero carbon by 2050?
My basic assumption is that IPCC are correct in their assesment of the impacts of Climate Change and what needs to be done to mitigate its effects.
There are less than 30 years between now and 2050 when IPCC are seeking a zero carbon world. 30 years is (roughly) the life cycle of a ship. If we are going to achieve a useful result, then we need to start acting NOW. What, if anything, can the shipping community contribute to that target?
In summary, the development aims for ships that have applied during the last decade need to be refocused. The only way the shipping industry can approach zero carbon operations is by switching to hydrogen, or hydrogen derivative, fuels. Development focus over the last decade that has led to lower pollution from ships (for example, the LNG powered P&O cruise ship Iona) simply does not generate sufficient reduction in CO2 to impact on climate change
On the one hand, I am encouraged that the technologies exist to transform the shipping industry into something close to zero carbon operation (though some aspects need to be scaled up to industrial use). On the other hand I doubt the political will to make it happen in the timescale required.
One problem is that hydrogen is difficult to store safely, and even derivatives such as ammonia require pressurised and/or cooled storage, and a greater volume per unit of energy too. This will make it difficult to convert existing ships to the new fuels. Success at scale may have to rely on fleet replacement.
There is a circular problem. Shipowners will need confidence that there will be sufficient supply of appropriate hydrogen based fuels distributed to where ships need to load bunker before they will commit to building new ships, or converting existing vessels. On the other hand, governments and/or investors will be reluctant to construct new renewable hydrogen generating plants (from which safe hydrogen derivative fuels can be made) until they are assured that there will be sufficient ships passing their coasts and requiring bunker; and/or suitable tankers exist to transport the hydrogen derivative to where it is needed. An additional frustration about this loop is that the generation of renewable hydrogen could generate much needed revenue for countries most affected by climate change because of the availability of plentiful and reliable solar power or wind.
The International Maritime Organisation (a UN Body) has proved to be far too slow to achieve results. The shipping industry itself has demonstrated that it will adopt new technologies, but only when they are proven to work. The essential Hydrogen based energy will be more expensive than classic fossil based fuels. It will probably take a mixture of seed grants, research grants, taxation, regulation and penalties to make the industry move at the pace required. Above all, an effective carbon tax will be required designed to make sure that shipowners that adopt the new hydrogen based technologies are not placed at a competetive disadvantage to the remaining traditional shipping stock. In an international environment, this will be difficult to achieve.
I cannot claim this is a scientifically rigorous exercise. None of the data is mine. I have tried to acknowledge sources, and if I have failed to do so anywhere, I sincerely apologise, I am simply an observer trying to make sense of a complex subject.
I started by wondering whether the shipping industry might be able to make a constribution to a zero carbon world. My journey had many surprises, and I can only describe what I have found out.
It goes something like this
Until about 2018 the shipping industry was focused on reducing pollution. Luckily this work would also lead to significant potential reductions in GreenHouse Gas emmissions( GHG), but not enough
A lot of work was done and it was realised that significant GHG reductions were possible. I have used the JOULES project (An EU research programme running from about 2016) to indicate how the industry was thinking. This project took a number of “application cases” that demonstrated that, from a 2018 starting point, certain progress could be achieved by 2025. Much more, with new technologies, might be achieved by 2050
But the reality is that, even if the projects proposed in the Joules Project had been implemented, the scale of the problem is so large that there was no chance that the proposed gains could have been achieved to a meaningful extent by 2025 across the world fleet.
Looking further ahead to 2050, some new technologies were proposed
But the intervention of IPCC changed the rules, lifted the bar. Instead of pollution, the goal had been shifted to Climate Change. The rumours grew, but eventually in 2021, IPCC declared that the goal had to be close to zero carbon dioxide emissions by 2050,
This left the shipping industry (and the legislators) on the back foot.
According to the 3rd IMO GHG study. shipping was responsible for about 2.5% of global greenhouse gas (GHG) emissions (probably an underestimate). That does not sound a lot, but it is a clearly measurable contribution to the climate change problem
Projects like the Joules report clearly established a direction of travel, but the new requirements showed that improvements in hand at 2021 were simply not enough.
Shipping (and aviation) had been left out of the progressive international agreements, such as the Paris Agreement, because they were too difficult to regulate.
In my opinion, the European Union has set up and funded useful research projects that have investigated what might be done, even if, until 2018 they were focussed on, pollution reduction rather than climate change targets.
There has been a growing appreciation that in order to achieve a zero carbon shipping world, there needs to be a migration towards hydrogen and hydrogen derivative fuels. One of the strongest candidates for this is ammonia. No progress in this direction can be made unless and until this technology shift reaches wide acceptance. It seems to be the only pathway that could be achieved widely by 2050 because it relies broadly on existing technologies.
One of the few companies that has engaged this paradigm is Ricardo PLC in the UK who have demonstrated that there are strong economic drivers toward the production of hydrogen derivatives such as ammonia in places like South America and Morocco by utilising the potential availability of hydrogen produced by renewable solar processes.
Other processes such as the pyrolysis process may make it possible to produce ammonia without having carbon dioxide as an unfortunate “waste” product. Such technologies are important, if not critical to the attempts to tame energy without adverse side effects.Various medium scale demonstrators of this process are already under way.
While it is tempting to think that in a world without oil (!) we will not need tankers, the reality is that we will still need some oil as feedstock to important chemical processes, and tankers for transporting hydrogen based fuels to where they are needed.
There may be opportunities to reduce the miles steamed by cargo ships. There are signs that the covid19 pandemic has forced some questioning of the desirability of very long just in time supply lines. That could lead to some manufacturing being relocated nearer to markets. Also, climate change has yielded a major benefit to shipping by opening the sea routes through the Arctic, shortening the sea journey from the far east to western Europe by about 40%.
There may also be limited opportunities to reduce the requirement for energy from fuels by using wind power on some ships. However, trials in the 1980s demonstrated that such gains are route sensitive, and there are operational issues, especially the need to avoid impeding cargo handling operations, and air draught in estuaries and rivers.
So, in a sentence, I am optimistic about the technology and pessimistic about the delivery timescale.
In conclusion regarding general emissions from ships, it seems that while demand for shipping might be constrained, there will continue to be a significant requirement for cargo to be moved. There appears to be no form of propulsion that would result in zero GHG emissions. However, of the options examined, it would appear that the use of ammonia as a proxy for hydrogen offers the best possibility, within the time window available for reducing emissions to the level where any residual GHG emissions could be compensated by an effective carbon trading market.
The conclusion is dependent on 4 assumptions
▪ Current trials of the pyrolysis process (or a successful alternative) for delivering zero GHG emissions ammonia at scale are successful
▪ Procedures to manage the combustion of ammonia in a wide range of large diesel engines can be developed that allow a sufficiently high replacement of fuel by ammonia without unacceptable level of NOx pollution
▪ Development of a clear carbon tax and an effective international carbon trading market which will be required to ‘mop up’ the residual GHG emissions. Given this, there should be enough commercial pressures to provide the motivation for adaptation to the new requirements.
▪ Retrofitting the main propulsion machinery of commercial ships within the available time window is impractical..
The result could be accelerated or improved by
▪ Systems such as the SGS wingsail that reduce the fuel burn (accepting that this is route dependent)
▪ Development of improved antifouling systems that are non-polluting.
▪ Provision of shore power for ships in port.