The shipping industry contributes approximately 3% of global greenhouse gas emissions, equating to nearly 10% of the transportation sector’s total carbon footprint.
With over 90% of the world’s goods transported by sea, decarbonizing maritime shipping is crucial to curb its environmental impact.
The International Maritime Organization (IMO) aims to cut the carbon intensity of international shipping by at least 40% by 2030 and net zero by 2050.
This article will outline 10 strategies to reduce emissions in maritime shipping, spanning from green technology investments to voyage optimization for a path toward sustainability.
10 Ways to Reduce Carbon Emissions
Carbon emissions refer to the release of carbon dioxide gas (CO2) and other greenhouse gases (GHGs) into the Earth’s atmosphere.
The CO2 and GHG discharge primarily come from burning marine fuels like heavy fuel oil (HFO) and marine diesel oil (MDO) in the main and auxiliary engines.
Here are 11 effective and actionable methods the shipping industry can implement to curb its carbon footprint.
1. Optimize Fuel Efficiency Using Energy-Efficient Technologies
Fuel efficiency means using the least amount of fuel to move a ship over a specific distance or operate for a certain duration.
This practice directly influences the amount of CO2 and other greenhouse gases emitted, as burning less fuel lowers emissions.
Energy-efficient technologies involve remodeling some parts of the ship such as propeller optimization, hull design improvements, hull coating specification, and air lubrication improve vessel performance and reduce drag.
Technologies to Improve Fuel Efficiency
- Propeller Optimization – Propeller upgrades, polishing, and optimized designs improve propulsion efficiency.
- Hull design improvements -Streamlining the hull, such as removing the bulbous bow, can sometimes reduce the ship’s resistance in the water.
- Drag-reduction coatings – A study by Jotun reveals that the correct antifouling technology frees the hull of microorganisms, thereby reducing friction.
- Air lubrication – Using microbubble technology under the ship’s hull to reduce friction and drag.
2. Improve Cargo Capacity and Load Optimization
Ships sometimes sail with slack cargoes or empty cargo holds.
Minimizing empty voyages or maximizing cargo on each trip through strategically planned routes significantly reduces fuel waste.
MacGregor’s Cargo Boost solution is pioneering this technology, which helps vessels optimize cargo stowage.
3. Transition to Low-Carbon Fuels
A shift from traditional bunker fuels to low-carbon alternatives like LNG (liquefied natural gas), biofuels, and methanol, which produce fewer emissions, significantly reduces carbon emissions.
LNG alone produces 20% to 30% less carbon than traditional heavy-fuel oil used by many ship engines.
Categories of Low-Carbon Fuels
- Low-carbon fuels are classified into three:
- Carbon-based – Includes MGO, liquefied natural gas (LNG), liquefied petroleum gas (LPG), methanol, and ethanol.
- Carbon Neutral – Includes biofuels, biomethane, and synthetic methane.
- Carbon Zero – Principally hydrogen and ammonia.
When it comes to decarbonization, hydrogen-based fuel (carbon zero) is the optimal choice.
Meanwhile, the trend of LNG-powered ships is slowly picking up, with a growth spurt between 20% and 40% per annum.
4. Enhance Crew Training and Awareness
Educating the crew on the importance of eco-friendly practices can make a significant difference, especially for companies with a large fleet.
Simple energy-saving policies can make a difference, such as switching off the lights in rooms when not in use, doing bulk laundry, managing waste, and saving potable water on board.
We had this poster below inside the accommodation that reminded everyone to conserve energy.
5. Use Alternative Energy Sources
Aside from low-carbon fuels, many ships are exploring other clean sources of energy, which are already producing results that reduce their carbon footprint.
Alternative energy sources tap into renewable solutions like wind, solar, and on-board batteries.
- Wind-Assist Solutions: These can be huge sails or a device called Flettner Rotors that uses wind energy to propel the vessel. Ships like Pyxis Ocean use sails, while Maersk Pelican’s Flettner Rotor Sails already saved 8.2% of fuel.
- Solar Energy: Solar panels can cut down fuel dependency by supplementing the power supply of ships. While common on small boats and yachts, merchant vessels are adopting this technology.
- Battery Energy Storage Systems (BESS): Reduces carbon footprint by enabling vessels to operate on stored electrical energy. By integrating BESS with traditional engines, ships can operate in hybrid mode, where batteries handle part of the energy load.
- Shore-side electricity (SSE): Also called on-shore power, SSE offers a 98% decarbonized result by allowing ships to shut down their engines and plug their power mains into the port electrical grid. This is similar to drydocking, where the vessel takes power from the yard, but here, it’s done on every port visit.
6. Practice Slow Steaming
Optimizing speed via slow steaming is the easiest and most practiced method many shipowners employ nowadays. By reducing speed, ships consume less fuel over the journey.
According to a case study, a 30% reduction in speed leads to a 2% to 45% reduction in carbon emissions, depending on the ship type.
Reducing speed to arrive precisely at scheduled docking times minimizes unnecessary fuel consumption compared to steaming at full ahead but only to anchor and wait upon arrival.
7. Utilize Trim Optimization
Trim optimization is the process of adjusting a ship’s trim to minimize hull resistance, lower emissions, and reduce fuel consumption by up to 5%.
Trim adjustments are usually made by redistributing loads, managing fuel placement, and modifying ballast.
The optimal trim depends on the ship’s specific design, speed, and draft and typically aligns with the ship’s hull form to minimize resistance.
The largest shipping companies, such as Hapag-Lloyd, Maersk Shipping, NYK Group, and Mitsui OSK Lines (MOL) uses trim optimization on their vessels.
8. Use Minimal Rudder Angles
Rudder movements create additional drag that increases resistance to the ship’s hull.
Using small rudder angles in open waters to keep the ship on track prevents excessive loss of speed.
Large rudder angles increase drag, which can reduce the ship’s speed.
Optimizing autopilot settings for environmental factors like wind, waves, current, speed, trim, draft, and water depth can lead to significant fuel savings of 0.5% to 3%.
9. Invest in Digitalization and IoT Solutions
Investing in digitalization and IoT solutions on ships can cut down on carbon footprints by improving operational performance.
This is done by monitoring fuel efficiency, predictive maintenance, real-time emission tracking, smart cargo loading and unloading, and optimizing energy management.
By adopting digitalization and IoT, shipping companies streamline operations and lower unnecessary vessel movements.
This will even make way for autonomous ships, or ships sailing the seas without actual crew on board!
10. Utilize Weather Routing
Weather routing is a strategic approach to optimizing routes based on weather forecasts, ship characteristics, and sea conditions.
It prioritizes safe and energy-efficient travel over simply the fastest route.
Key Components:
- Weather forecasting and analysis
- Ship performance modeling
- Route optimization algorithms
- Real-time data integration
By implementing weather routing systems in the vessel’s voyage plan, ship operators can expect fuel savings of up to 10% under optimal routing conditions.
Now imagine all the largest ship-owning countries implement these methods. The maritime sector’s carbon emissions could drastically fall, and we could be on track to sustainable shipping.
May the winds be in your favor.