What are the Options for Sustainable Shipping?

What are the options for sustainable shipping? It is a crucial time for the shipping industry as the options are weighed about what the future should look like.This is a broad overview of the sustainable options on the table from hydrogen to wind.

The 21st century is going to be a century of revision. The last hundred years saw globalism raise the average quality of life across the board. Every metric has improved from literacy to freedom, access to clean water and the lowering of infant mortality. What has this globalism-spurred growth cost? Ask Mother Nature. The ozone hole, plastic islands and the all encompassing climate change. We built and built and built and now on the penultimate of collapse we need to revise how we will continue this upward mobility of humanity. We need to revise the fuels in our largest industries and a good place to start is with shipping. 

90% of world trade is carried out over the oceans meaning most of the things around you right now have spent time in a shipping container. If the shipping industry were a country it would be the 6th largest greenhouse gas emitter in the world contributing 3% of global emissions. This is an industry with little regulation and an anachronistic method of propulsion; burning the dredges of leftover fossil fuels. Conventional container ships currently use bunker fuel which is fractionally distilled from crude oil. It is a thick sludge that must be preheated before it can be burned in the ship's engines. It is literally the bottom of the barrel. It emits large quantities of greenhouse gas pollutants and because of how cheap it is, has spurred globalization. Not only enabling it but actively pushing it forward. 

Problem

The problem is in regulating the sprawling nature of shipping and international trade. As The New York Times put it “shipping, unlike other industries, is not easily regulated nation-by-nation. A Japanese-built tanker, for instance, might be owned by a Greek company and sailed by an Indian crew from China to Australia — all under the flag of Panama.” 

The shipping industry has a well deserved reputation for lurking in regulatory shadows due to its transient omnipresence. The governing body of world trade is the International Maritime Organization (IMO). As a regulatory body under the United Nations, it sets broad emission goals but unlike a government overseeing its corporations the IMO cannot enforce its vision; it must rely on individual countries to administer. While the IMO has set the goal of 50% reduction of greenhouse gas emissions by 2050 it is the responsibility of individual countries and shipping companies themselves to decide how to meet that goal. 

Dan Rutherford from the International Council on Clean Transportation put it succinctly, “A lot of [cargo] carriers and technology providers are trying to figure out what the alternative to bunker fuel is.”

It is very likely that it will be a combination of technologies that replaces fossil fuels. What the predominant solutions will be remains unseen and the leading contenders all require significant supply chain infrastructure that needs conversion to renewable production.  

There are also several bridge solutions such as Liquid Natural Gas (LNG) or CO2 reduction systems but unlike other bridge fuels discussed here they do not originate from renewable resources and thus are not considered a sustainable solution. Below, in no particular order, are sustainable replacements for fossil fuels under consideration by the industry's leading players. Hydrogen, ammonia, methanol and wind. 

Hydrogen

Hydrogen fuel cells have been a popular concept and are often held up as the future of sustainable energy. However production costs of the fuel cells and logistics of hydrogen storage and distribution have been barriers to its acceptance. This is slowly beginning to change as cell manufacturing becomes cheaper and new technologies developed. At the moment hydrogen is already being globally produced for different industries but it needs to be scaled and switched to renewable energy production.

The production of hydrogen requires immense amounts of electricity which is typically generated from fossil fuels. Production uses electrolysis, which separates water molecules into hydrogen and oxygen. The ubiquity of hydrogen and the simplicity of the process means that production facilities can be built in every country. Small developing countries that previously had to import oil to refuel ships now can sell their own liquid hydrogen. Or build small inter-island or coastal ships which can be refuelled anywhere.  

“The new generation of zero-emission fuels for maritime transport will not only benefit in the fight against climate change and the local need for better air quality. But they also offer a $1+ trillion investment opportunities in developing countries.” said Dominik Englert and Andrew Losos in a World Bank blog

In countries like Costa Rica where 99% of electricity is generated from renewable sources there is great potential for green hydrogen production. Companies like Ad Astra who built a green hydrogen bus in the capital San Jose see that potential. They are already producing green hydrogen in Libera and have plans to expand hydrogen fuel cells into other sectors. 

“Both the EU and some within the shipping industry see hydrogen as a key contributor in the efforts to mitigate climate change” says Ships Insight. With green hydrogen production using renewable electricity and fuel cells powering electric engines it could be a truly zero emission system all the way down the chain. Currently hydrogen fuel cells are being tested in smaller vessels such as passenger ferries and canal boats with plans for cargo ships in the future. 

William Alan Reinsch, a Senior Adviser at the Center for Strategic and International Studies, said that “Despite the cost challenges, hydrogen is the most promising clean fuel option for the global shipping industry. Many leaders in the transportation and energy sectors have realized this and have begun to invest in research and development to reduce production costs and explore scalability.”

Some tangible evidence of that fact is the move by the oil company Royal Dutch Shell which is backing hydrogen as the future of shipping fuels. In a recent project dubbed NortH2, the alliance backed by Shell, is building offshore wind farms to generate green hydrogen with the goal of 10 gigawatts by 2040. 

The largest drawback right now is cost and storage. The precious metals used inside fuel cells are expensive however this cost will continue to go down as new technologies are developed. Liquid hydrogen, which provides the best density and least efficiency loss must be stored at cryogenic temperatures around -253 C meaning special, and expensive, containers must be used. 

Hydrogen is set to be one of the most important fuels of the future and with large companies beginning to invest in infrastructure it is becoming increasingly important. 

Ammonia

Ammonia can be used as a low carbon bridge fuel in combustion engines until fuel cells are more common. This makes it appealing as a potential short and long term solution.  It is currently used to make agricultural fertilisers but as with hydrogen, the production process has to be switched to renewable energy. Ammonia can be created from methane gas as it is now or by combining green hydrogen and nitrogen.  While there is existing infrastructure for ammonia for use as a fertilizer supply chains will need to be scaled up extensively for use in shipping. 

It can also be used as a carrier for hydrogen giving the flexibility of multiple uses. As Black and Veatch said in a statement, “While hydrogen has the advantage of high energy density (on a mass basis), the large storage volumes required, and limited existing infrastructure are considered stumbling blocks in the hydrogen as fuel economy.  One solution to this hurdle is to consider a hydrogen carrier, such as ammonia, for the transportation and storage of the fuel and crack it back to hydrogen at the user.”

This process of “crack(ing) it back to hydrogen at the user” is a fairly straightforward process using a simple catalyst. This gives all of the benefits of ammonia with the energy density of hydrogen. 

NCE Maritime Cleantech cluster chief executive Hege Økland says “As we move onto the right trajectory to achieve these targets, we see interest in new fuels such as ammonia and hydrogen increasing. Ammonia is an abundant energy source and can easily be made from renewable resources making it one of the fuels that will likely meet part of shipping’s future energy demand.” 

The challenges to ammonia are summed up well by The International Centre for Sustainable Carbon “One concern is that ammonia is toxic and flammable. However, there are existing procedures, like scrubbers, to deal with this. These just need to be popularized outside of sectors that already use ammonia and its derivatives. Ammonia also produces nitrogen oxides (NOx) at a time when the likes of the International Maritime Organization are putting tight restrictions on such pollutants.”

As with all of these solutions there are advantages and serious disadvantages that need to be worked out. Moving on to methanol...

Methanol 

Methanol is another example of a fuel that could theoretically be produced without emissions and could be a low carbon short term solution until the supply chains are refined. There are two kinds of methanol, one which is produced through the reactions of hydrogen with carbon dioxide from industrial exhaust and the other which is created using organic matter transformed through a gasification process. Either method can use renewable energy to make a completely sustainable supply chain, however again, the large-scale production of zero emission methanol does not currently exist. 

There are of course the same downsides for methanol as there are for all of the above “electrofuels” or fuels that require electricity to produce. “...it shares a problem with all electrofuels – it’s expensive to produce. Electricity is necessary both for the production of hydrogen gas and the actual methanol, and the equipment itself requires major investment, at least for the time being” - Selma Brynolf, scientist at the Department of Mechanics and Maritime Sciences at Chalmers University of Technology in an interview with Wallenius Shipping Company. 

To underline this point Dan Rutherford from the ICCT reminds us “As in all things fuels, the good stuff is not the cheap stuff. And the cheap stuff tends to be comparable in greenhouse gas emissions to heavy fuel oil today.”

Maersk, the largest shipping company in the world, is hedging their bets on e-methanol.  With their initial projection to be emission free by 2050 they have promised to launch a carbon neutral vessel by 2023 which will use e-methanol.

“It will be a significant challenge to source an adequate supply of carbon neutral methanol within our timeline to pioneer this technology. Our success relies on customers embracing this groundbreaking product and strengthened collaboration with fuel manufacturers, technology partners and developers to ramp up production fast enough.” says Henriette Hallberg Thygesen, CEO of Fleet & Strategic Brands, A.P. Moller - Maersk.

Just in case e-methanol can’t be supplied in sufficient demand the ship can also run on conventional fuel.

The chicken and egg conundrum is a recurring theme. Energy producers won’t invest in clean solutions until there is demand from shipping companies and vice versa. Large companies like Maesk are trying to make the first large step but it's a slow process. 

Wind

For most of human civilization the power of the wind has been used to trade with one another. Even past the invention of coal powered engines, sails were still being used onboard steamships. The SS Great Eastern was a sailing steel steamship 211 meters long and was designed to carry 4,000 passengers from England to Australia without refueling, it was the largest ship in the world for four decades. This is a great example of a transitional period where different technologies were used together to create low fuel transportation. 

Wind is the only totally green source of energy for ocean transport available right now. While it needs to be scaled for use on the largest container ships, the proponents of wind propelled ships don’t agree that it needs to be. They counter that perhaps ships don’t need to be so large to begin with. Smaller ships with diverse and flexible solutions can help achieve greater resiliency in the face of the climate crisis. 

Wind systems also provide a more resilient industry by allowing access to free energy. The great benefit for wind systems is the lack of additional infrastructure needed once the sails are installed. Unlike other energy systems wind is the only inherently green energy source available immediately. 

We can easily envision a future where a container ship is propelled by a combination hydrogen fuel cell engine and sails. This is already being done on the ships of SAILCARGO INC. and could be scaled up. Today, there are a variety of wind systems from traditional canvas sails, rotors, Dyna Rig or solid ‘wings’ which can all be used in tandem with sustainable fuels. 

The International Windship Association is an emerging group with over 130 members, mostly shipbuilding companies that have declared 2021-2030 as The Decade of Wind Propulsion. “There are already 11 large ocean-going vessels with wind-assist systems installed, with over 20 rigs installed along with two more installations pending this quarter and a further 20+ smaller sail cargo and small cruise vessels using wind; that is more than all current new alternative fuelled vessels combined,” adds Gavin Allwright, IWSA Secretary General.

Innovative sail designs include the EcoLiner which uses carbon fiber rotating masts with automated sails and an electric engine. This technology could be used for intercoastal cargo ships where larger ships aren’t able to easily reach.

At the moment wind has a very small share of the industry's energy source however there are a number of designs in development. Companies incorporating wind as the primary propulsion include Sailcargo Inc. EcoClipper, NeoLine, OceanBird and others. Once these prototypes have been proven successful they will be an example for the world's largest shipping companies. They show that a diverse array of solutions are not only viable but are in demand.
 

Conclusion

“Ship engines that run on ammonia, hydrogen and biofuels are being tested but the fuels aren’t yet available in the volumes needed and all come with potential drawbacks. Hydrogen tanks occupy a lot of cargo space, ammonia is highly toxic if spilled in the water, and some biofuels require large areas of farmland to be devoted to plants such as sugar cane which brings its own potential for environmental damage. “ says Costas Paris journalist at the Wall Street Journal.

Companies are just now placing orders for ships that will make up the world's fleet in the coming decades and there is much uncertainty about the future. The growth of the shipping sector shows that there is enough market demand to necessitate a diversity of solutions. For instance, the success of SAILCARGO INC proves there are enough people willing to pay extra for zero emission value added products simply because they can see the very real and direct impact a zero emission ship makes.

As is the case with transitional periods new technologies will be more expensive until the supply chains are worked out. There is a lot of work to be done but one ship at a time we will sail towards a cleaner future. 

Bibliography

Intro

Proof that life is getting better for humanity, in 5 charts.  Vox -The Big Idea
Tasked to Fight Climate Change, a Secretive U.N. Agency Does the Opposite.  The New York Times
The International Council on Clean Technology. The ICCCT
Zero-emission shipping: What’s in it for developing countries? World Bank Blog

Hydrogen
First Hydrogen Fuel Cell Bus Arrives in Costa Rica. The Costa  Rica News
Flagships’ hydrogen-fuelled cargo ship planned for 2021 debut. ShipsInsight
Hydrogen: The Key to Decarbonizing the Global Shipping Industry? Center for Strategic and International Studies
Shell backs hydrogen for shipping’ decarbonization. Royal Dutch Shell Group. 
Hydrogen For Industry. North2

Ammonia
Ammonia: zero-carbon fertiliser, fuel and energy store. The Royal Society
Ammonia: Fuel vs. Hydrogen Carrier. Black and Veatch Inc

Methanol
Renewable Methanol Report. The Methanol Institute, PDF
E-methanol – the future fuel? Wallenius-Sol
Maersk will operate the world’s first carbon neutral liner vessel by 2023. Maersk

Renewables
The futuristic cargo ship made of wood. BBC
The Future of Climate Friendly Shipping. FairTransport
Rotor Sails. Norsepower
Dynarig. Wikipedia
Solid Wing Sails. The Oceanbird
Decade of Wind Propulsion. The International Windship Association
Ecoliner. Dykstra Naval Architects.
U.S. Push for Carbon-Neutral Ships. Costas Paris for Wall Street Journal

Additional Reading
Shipping’s Carbon-Cutting Fuel Tanks So Far Remain Empty. Wall Street Journal
Renewable Energy Options of Shipping. The International Renewable Energy Agency
Dream Boat. Grist
Toward the Optimization of Hydrogen, Ammonia, and Methanol Supply Chains. ScienceDirect
Decarbonising shipping – could ammonia be the fuel of the future? Lloyd’s Register
Powering a Low-Carbon Future With Methanol as a Marine Fuel. The Maritime Executive
Future Fuels – Ammonia and Methanol. FRESA Blog
Too many alternative fuel options for the shipping industry? Fuels and Lubes
Five percent zero emission fuels by 2030 needed for Paris-aligned shipping decarbonization. The Global Maritime Forum
Ammonia - The foul-smelling fuel that could power big ships. BBC
What's the Green Fuel for the Future of Shipping? Bloomberg News