3 exciting ways to reduce the ridiculously high carbon footprint of shipping
Ships carry over 80% of global trade and rely heavily on some of the less environmentally friendly transport fuels available.
There are no cheap and widely available solutions that can reduce the global warming carbon emissions of the shipping industry – in fact, shipping is considered one of the hardest industries to decarbonize. on the planet – but some exciting innovations are currently being tested.
As a professor of naval architecture and marine engineering, I work on ship propulsion and control systems including electrification, batteries and fuel cells. As attention turns to climate change this week as world leaders gather at the G-7 summit and negotiators discuss shipping emissions at a meeting of the United Nations International Maritime Organization , let’s take a look at what’s possible and some of the fuels and technologies that may be defining the future of the industry.
The climate problem of maritime transport
Shipping is the cheapest way to transport raw materials and bulk goods. This has given it both a huge economic impact and a significant carbon footprint.
The industry emits about 1 billion metric tonnes of carbon dioxide per year, or nearly 3% of global emissions, according to IMO, a specialized United Nations agency made up of 174 member countries that sets standards for the industry. . If shipping were a country, it would rank between Japan and Germany as the sixth largest contributor to global carbon dioxide emissions. In addition, almost 70% of ship emissions occur within 250 miles (400 kilometers) of land, which means that this also has an impact on air quality, especially for port cities.
Technological innovation, in addition to policies, will be crucial to achieve low-carbon or zero-emission maritime transport. University research institutes, government laboratories and businesses are now experimenting with electrification; zero or low carbon fuels such as hydrogen, natural gas, ammonia and biofuels; and alternative energy sources such as fuel cells and solar, wind and wave power. Each has its advantages and disadvantages.
Why electrifying ships is important
Just like on earth, electrification is one of the keys to cleaning up industry emissions. It allows fossil-fueled engines to either be replaced by alternative power generation technologies, or downsized and modified for low-emission operation. It also allows ships to connect to electricity while in port, reducing their emissions from idling.
The electrification and hybridization of ships are important trends for commercial and military vessels. Electrifying a ship means replacing its traditional mechanical systems with electrical systems. Some fleets have already electrified the propulsion and handling of goods. Hybrid power systems, on the other hand, integrate different power generation mechanisms, such as motors and batteries, to take advantage of their complementary characteristics.
I see deeper electrification and broader hybridization as a basic strategy for achieving green shipping.
Huge opportunities also exist to improve the operation of the existing fleet – and reduce fuel consumption – through automation and real-time control. Advanced sensors, artificial intelligence and machine learning can help ships ‘see’, ‘think’ and ‘act’ better to improve efficiency and reduce emissions.
Greener fuels for ocean travel
The shift to cleaner and greener fuel sources will be essential to decarbonize the shipping industry.
Most of the power plants on ships today are based on internal combustion engines that use cheap heavy fuel oil. Innovations in marine diesel and gas turbine engine design and exhaust gas treatment have reduced harmful emissions. However, most of the “fruits at hand” have been harvested, with little room for dramatic improvement in traditional energy sources.
The focus is now on developing cleaner fuel sources and more efficient alternative power generation technologies.
Low- or zero-carbon fuels, such as natural gas, ammonia and hydrogen, are expected to be the main sources of energy for maritime transport in the future. Ammonia is easy to transport and store, and it can be used in internal combustion engines and high temperature fuel cells. But like hydrogen, it is still largely made from fossil fuels. It is also toxic. Both have the potential to be made with water and renewable energy using electrolysis, but this zero-carbon technology is still in its infancy and expensive.
These fuels have started to replace heavy diesel fuels in some marine segments, primarily as demonstration projects and at a slower pace than necessary. Costs and infrastructure remain major obstacles.
Renewable energy sources, such as wind, solar and wave power, are also promising. Integrating renewable sources as cost-effective and reliable energy solutions for ocean-going vessels is another challenge the developers are working on.
Power ships using fuel cells and batteries
Fuel cells and batteries also show promise as alternative power generation technologies.
Through electrochemical reactions, fuel cells generate electrical energy in a very efficient and clean manner, which makes them very attractive for transportation. Fuel cells operate on pure hydrogen or reformed gases, with the exception of high temperature fuel cells which can use natural gas or ammonia as fuel.
Given the existing fuel infrastructure, most marine fuel cell demonstration projects today must store liquid hydrogen or use on-board systems that convert natural gas or other fuel into rich syngas. in hydrogen. Hydrogen storage infrastructure needs to be developed for widespread adoption of fuel cell technology.
Battery technology is essential for electrification, even for ships with an internal combustion engine as the main engine. It also has its own unique challenges. Along with ensuring the batteries are safe and reliable – you don’t want a fire or power outage in the middle of the ocean – ruggedness and flexibility are needed to power operations such as cargo handling and operations. of tugboat.
Invest in the future
In 2018, the International Maritime Organization’s Committee for the Protection of the Marine Environment set targets to reduce the carbon intensity of the global fleet by at least 40% by 2030 and to halve its greenhouse gas emissions by 2050 compared to 2008 levels. It is expected to adopt mandatory requirements reflecting these long-term goals at its meeting on June 10-17, 2021.
These goals are important, but they push the time frame for action into the future.
Countries and some shipping companies recommend a faster transition. In early June, the governments of Denmark, Norway and the United States, along with the Global Maritime Forum and the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping, announced a new zero-emission maritime transport mission to attempt to step up and deploy new green maritime solutions more quickly.
Shipping giant AP Møller-Maersk has said it could support a carbon tax of $ 150 per tonne of carbon dioxide to encourage more innovation and a faster transition, although others in the industry argue that such a tax would almost double the cost of bunker fuel. and make freight much more expensive, with repercussions for the entire world economy.
I believe the grand vision of zero-emission shipping can be achieved if the ship design and fleet operations communities work together with policy makers, the logistics industry and the broad technical, academic and industrial communities to find solutions. solutions.
It is an exciting time to work in the field of energy and electrical solutions for maritime transport. The technology developed today will have a transformative impact, not only on the maritime industry but also on society.
This article by Jing Sun, Professor and Department Head, Naval Architecture and Marine Engineering, University of Michigan is republished from The Conversation under a Creative Commons license. Read the original article.