View of leafs forming a ship

Supporting the global energy transition through marine energy efficiencies

Jan. 28 2021

It is important to differentiate between energy efficiency and the energy transition. Energy efficiency implies more efficient design and operations. Shipowners and operators require fuel efficient vessels to help drive down costs. Over the past decade, concern with environmental stewardship has escalated, leading to a push to reduce GHG emissions as well. When maritime companies run more efficient operations, they deliver on necessary climate risk reduction promises while simultaneously increasing their profits.

This leads us to the energy transition, which focuses on new systems and fuels to power the future. The International Maritime Organization’s (IMO) decarbonization objectives are demanding, which means that efforts must extend beyond vessel efficiency to include new fuels, propulsion techniques and ways of producing energy onboard.

 

Green fuels ease environmental impact

The trend today, particularly in Europe, is to eliminate fossil fuels as soon as possible. Shipowners are investigating new fuel types such as ammonia and hydrogen.

Ammonia is a carbon-free fuel that is less dangerous and explosive than hydrogen. While ammonia is already transported and stored onboard vessels in the agricultural and chemical industries, knowledge is lacking on how engines respond to its use, particularly over the long term. Ammonia also gives off nitrogen oxide (NOx) emissions and is rather toxic to human and marine life. Proper risk and technical analyses are crucial prior to developing structural integration solutions onboard.

Abundant and inexpensive, hydrogen only emits water, making it particularly promising for use at sea. However, there are some challenges to overcome before it sees use. Hydrogen is the smallest element: it can thus leak through pipes and must be stored at very high pressure. This means ships will need to be designed with expanded space for hydrogen fuel, while ensuring that cargo capacity can be maintained.

Liquefied natural gas (LNG) has become very popular for seagoing vessels over the last decade, due to its enormous availability and compatibility with existing infrastructures. LNG represents a 99% reduction in NOx and sulphur oxides (SOx) emissions. It can also reduce carbon dioxide (CO2) emissions by up to 20%—still shy of IMO targets, but a step in the right direction.

Carbon capture technology offers great potential. The process, which removes CO2 from exhaust pipes for reuse as energy, is already being used successfully onshore. Applied to shipping, it could be combined with LNG use as a long-term renewable energy solution. However, transferring the technology to build a robust maritime infrastructure would be extremely costly.

 

New technologies lower emissions and cost

Some IMO objectives seem far off on the timeline, stretching to 2050. But many of today’s newbuilds are likely to be in the fleet 30 years from now. Shipowners need to invest in green design now, which means finding the most forward-thinking design strategy for newbuilds and existing vessels.

Developments are underway to capture wind using rigid sails that would be attached to seagoing vessels. 

Engineers are also designing futuristic-looking wings and Fletner rotors for existing ships or newbuilds. These innovations enable ships to harness wind power, covering 10-20% of a ship’s needs.

Air lubrication systems are another way to streamline a ship’s efficiency. These systems inject air bubbles onto the ship’s hull. Because air friction is lower than water friction, this introduces a skin of air that reduces water viscosity. Devices like these can be installed on a newbuild, resulting in 1-5% efficiency savings. While that might not seem like a lot, every little bit counts.

New energy-saving rudder designs that enable flow behind the propeller can be retrofitted onto existing assets. Containerships are seeing more and more general use and corresponding energy savings. To aid with incoming flow, fins, vortex generators and ducts can all be added before the propeller.

Shipowners are also working to maximize energy efficiency from an operational standpoint through weather routing. This technology determines optimal trajectories by studying a ship’s hydrodynamics and relevant wind systems. Fuel reductions occur by lowering resistance as ships follow prevailing winds and waves, and spend less time in harsh environments.

Vessels can also significantly reduce operating expenses and fuel consumption by optimizing trim. Trim optimization selects the trim condition for minimum resistance and thus less required power and fuel. This results in lower emissions and more economic operations.

 

BV Solutions M&O is helping lead the energy transition

Navigating the array of energy-saving systems, technologies and fuels is a challenge for marine owners and operators. BV Solutions M&O has the expertise to help its clients in the energy transition. New technologies bring new risks. For example, cargo capacity must be confirmed for newbuilds intended to deploy an alternative fuel such as hydrogen. BV Solutions M&O performs risk assessments and feasibility studies to ensure optimal fit.

Owners also need to perform timely energy audits, which provide a systemic evaluation of ship design, configuration and operating profile. BV Solutions M&O performs hydrodynamic evaluations to facilitate the creation of detailed ship models using its proprietary SEECAT software. This audit helps owners define the most appropriate solutions to improve vessel efficiency as well as potential energy gains. Fleet owners gain a quick, accurate understanding of vessel optimization benefits. BV Solutions M&O can also help outfit newbuilds and retrofits with sails and other external options to reduce engine use and fuel consumption.

Owners and operators who aim to be at the leading edge in terms of green design and operations turn to BV Solutions M&O. The challenges of the energy transition will be with us for generations to come. With engineers who are focused on the future, BV Solutions M&O has the experience and expertise to steer the marine industry toward greener shores.

10-20% The energy benefit of using wind assisted devices
Photo of Yohan Le Gonidec
Yohan
Le Gonidec

Head of Shipowner Support and Naval Architecture Section

BV Solutions M&O

Within the energy transition, shipowners are looking for ways to run their ships more efficiently, which in turn reduces the amount of CO2 emissions.