Marine propulsion is the mechanism or system used to generate thrust to move a ship or boat across water. The maritime industry is well on its way to a greener and more sustainable fleet. The latest installations of wind propulsion technology on large commercial vessels have tipped the amount of cargo that can be transported on vessels that make use of wind as a renewable energy source over the one million tonnes of deadweight (DWT) milestone, reported in Sep 2022.
The main goal is to minimize the environmental impact of all vessels worldwide. The Fleet Transition Plan shows the ambition to reduce carbon intensity of its controlled fleet to 50% by 2030, compared to the level of 2008. Still, if we don’t take more drastic measures, emissions will increase between 50% and 250% by 2050 under a business-as-usual scenario, according to the International Maritime Organization (IMO).
In recent years, there has been a resurgence of interest in equipping vessels to harness the power of the wind. What was once romanticized as a historic way to sail cargo across the world’s oceans has become a credible option for modern vessels, fueled by incoming carbon reduction targets and high fuel prices.
Gavin Allwright, IWSA Secretary General says: “Wind propulsion technologies are proven to save 5-20% in fuel use and associated emissions when used as wind-assist on motor vessel profiles. The savings potential is even higher for vessels that use primary wind technologies to achieve much higher levels of propulsive energy sourced from wind. This makes wind power a valuable pathway to reducing the emissions of the international shipping industry immediately and over the longer-term. It also offers the potential for enabling a substantial reduction in the carbon intensity of the whole fleet.”
To achieve the safe upper limit for global warming of 1.5 degrees Celsius, ‘all ships designed and built today must operate in a net zero emission world at the end of their service life,’ says Gavin Allwright, Secretary General of the International Windship Association.
He calls wind propulsion a ‘primary renewable’ that requires no new infrastructure. ‘It can deliver savings of up to 30 per cent for retrofits and possibly even more for optimised newbuilds.’ Other benefits, Allwright points out, is that the technology is available now. In addition, there are lease options and modular rentals to reduce capital cost. He stresses the availability of secondary renewables such as NH3/H2 and batteries is possibly still a decade away. He adds that ‘hybrid solutions will reduce power requirements, will lower bunkering and storage requirements and reduce both capital and operational expenditure.’
Currently, twenty-one large commercial vessels have wind propulsion systems installed onboard representing over one million DWT of cargo carrying capacity. By the end of this year, IWSA estimates that wind propulsion technology will be installed on around twenty-five large commercial vessels, representing 1.2 million DWT. Based on public announcements and shipyard orders made to-date, IWSA also estimates that by the end of 2023, up to fifty large ships will be making use of wind as a renewable energy source with a combined tonnage of over three million DWT.
In addition to the fleet of large commercial ships sailing with wind propulsion technology installed, ten small cruise ships currently use traditional soft sail technology representing a further 50,000 Gross Register Tonnage (GRT). There are also a growing number of smaller vessels (under 400 GRT) using wind propulsion technology. The number of smaller vessels will also likely grow in the next year as more vessels are converted to sail cargo, retrofits on small fishing vessels are undertaken, and a demonstrator vessel is launched in the South Pacific.
The EU has forecast that up to 10,700 wind propulsion installations could be in place by 2030, covering 50% of the bulker market and up to 65% of tankers. This will in turn reduce emissions by 7.5m tonnes of CO2. The UK Clean Maritime Plan forecasts that wind propulsion technologies will become a GBP2bn a year segment, with approximately 37,000-40,000 installations (equivalent to 40-45% market penetration) by the 2050s.
The Navy and industry are investing in propulsion technologies that offer the potential to improve future naval ship designs. The goals of the current and planned technology development efforts are to improve affordability, power density, efficiency, and satisfy the energy demands of future mission systems. New generations of ship must meet new challenges, particularly in terms of energy efficiency, reliability and environmental impacts. Wind propulsion technologies are emerging as one option which can help cut fuel costs significantly, make vessels compliant with existing and impending emission regulations and create energy security and long-term resilience in a volatile market.
The International Windship Association (IWSA) is spearheading a ‘Decade of Wind Propulsion’ campaign to accelerate the adoption of hybrid alternative propulsion methods for shipping, helping to steer the industry toward decarbonisation. Three key elements of the Decade of Wind Propulsion campaign include the delivery of retrofit systems and newbuild projects, the optimisation of existing systems alongside new concepts, and the facilitation of hybrid systems.
“Pressure to swiftly decarbonise international shipping is growing from all sides. The roll out of new low-carbon fuel systems will take considerable time and resources. Wind gives us the unique opportunity to deliver up to a third of the fleet’s propulsion energy requirements without the need for new infrastructure, right now,” Allwright said.
Wind power technology
Wind power offers the only truly emission-free, zero-cost energy source that can be delivered directly to a ship while it is sailing without fuel security or supply threats. The use of this abundant, globally available energy source, partially with wind-assist technology or as the primary energy source for a vessel’s propulsion, can represent a substantial portion of the total energy requirement of a vessel throughout its operational life.
Over a period of centuries and even into the 20th century, wind driven vessels carried trade between nations. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or engine turning a propeller, or less frequently, in pump-jets, an impeller.
The use of wind propulsion in modern commercial shipping covers a wide spectrum from wind-assisted motor vessels, where auxiliary propulsion is provided by wind to primary wind ships with auxiliary engines, where primary propulsion is from the wind, augmented by engines to ensure just-in-time schedules are maintained .
It was during the 1980’s that Canadian physics professor Dr. Brad Blackford built a small windmill powered boat capable of sailing into a headwind at great speed than sail-driven boats of comparable size. He eventually built a boat capable of sailing directly into a headwind at a speed of 8-knots.
In April 2018, cruise ferry M/S Viking Grace became the world’s first passenger ship equipped with a rotor sail, a vertical spinning cylinder that harnessed wind power to propel a ship. The rotor installed on board Viking Grace is expected to slash the vessel’s fuel consumption and reduce carbon emissions by up to 900 metric tons annually. “Norsepower’s mission is to reduce the environmental impact of shipping by providing efficient, easy to use and reliable auxiliary wind propulsion for ships. Auxiliary wind propulsion is one of the key technologies for shipping to achieve the demanding fuel and emissions reduction requirements,” said Tuomas Riski, CEO, Norsepower.
Ships assisted with vertical-axis Flettner rotor propulsion have also proven capable of sailing directly into a headwind, the rotors driving electrical generators to activate electrically driven propellers. Flettner rotors are an example of a growing wind propulsion trend in the industry, with many new vessels outfitted with rotors.Modern wind- assisted propulsion technology differs from conventional sails in terms of efficiency, smaller windage area, and automatic control systems. New technologies leverage wind thrust and automatic control systems to optimize thrust force generation, adapting to wind conditions.
A high-viable test project is underway designed to help validate and increase the use of wind-assisted propulsion technologies in the maritime world. Funded by the Wind Assisted Ship Propulsion (WASP) project that was launched in late 2019, a wind rotor was installed on a ferry as one of five test vessels operating in the North Sea and Baltic.
Modern commercial vessels incur many times the weight of earlier generation wind-driven ships and require many times the propulsive power. The combination of environmental exhaust emissions regulations and fuel prices have prompted introduction of wind assisted vessel propulsion involving sails, kite sails, bladed horizontal-axis turbines and vertical-axis Magnus rotors. The power requirements of large commercial ships require future innovative breakthroughs in the variation and physical size of wind propulsion technology.
Commercial tankers using sail power to navigate the seas could be the wave of the future.
Norsepower Oy Ltd, a Finnish engineering and technology company announced in March the installation and testing of Flettner rotor sails onboard a Maersk Tankers vessel. The project, which will be the first installation of wind-powered energy technology on a product tanker vessel, would provide insights into fuel savings and operational experience.
Maersk Tankers will supply a 109,647 ton Long Range 2 product tanker, which will be retrofitted with two 98 feet tall by 16 feet in diameter Norsepower Rotor Sails. The design would look like narrow smoke stacks. Combined, these are expected to reduce average fuel consumption on typical global shipping routes by 7-10 percent.
The Norsepower Rotor Sail is a modernized version of the Flettner rotor — a spinning cylinder using the Magnus effect to harness wind power to propel a ship. Each Rotor Sail is made using the latest intelligent lightweight composite sandwich materials. When wind conditions are favorable, the main engines can be throttled back, providing a net fuel cost and emission savings, while not impacting scheduling.
Norsepower’s Rotor Sails may not already be installed on the 20,000 applicable vessels in the global fleet, but we have a proven commercial product that could reduce emissions by 10 to 15% per ship,” Mr Riski continued. Tuomas Riski, CEO of Norsepower, said in a release: “As an abundant and free renewable energy, wind power has a role to play in supporting the shipping industry to reduce its fuel consumption and meet impending carbon reduction targets.”
He explained that this does not limit the reductions that could be made by those ships, as multiple technologies sit happily alongside Rotor Sails, like hydrodynamic hull optimisation, heat recovery, and alternative fuels.
Wave power meets space technology – for smarter, zero carbon ocean monitoring
Pioneering marine technology start-up, AutoNaut Ltd, has developed the AutoNaut USV propelled entirely by the waves, with zero carbon emissions. It is one of the world’s first small commercial applications of wave propulsion technology and can operate at sea for months at a time, covering hundreds of miles in a week in areas and operations too hazardous for humans. It is so quiet it can measure the whistles and clicks of dolphins over large areas.
Remotely controlled from anywhere in the world via satellite, the AutoNaut houses cutting edge, solar powered sensors that capture raw research data, which are analysed, processed and then sent back to the operator on land, anywhere in the world, via a satellite communications network.
Wind power in the mix
Wind-assisted propulsion will not be the full answer to making ships emission free, but it could provide about 30 per cent of the propulsive power. This makes finding a zero-emission solution for the other 70 per cent an ‘easier nut to crack’, says Gavin Allwright, Secretary General of the International Windship Association. That is why he expects the wind-assist market to really take off in the coming years.
And there is a question of range. Some of the possible zero-emission solutions are not (yet) suitable for shipping. The equipment needed would become too expensive, too large, too heavy or does not supply enough power. ‘Yet, if 30 per cent of the propulsive power needed is provided by wind, you only have to worry about the other 70 per cent,’ Allwright explains.
He sees a mix which he describes as W.A.V.E.: wind, activity, vessel and eco-fuels. In his view, wind will supply up to 30 per cent of the power supply. Operational optimisation (activity) can result in a 20 per cent power saving, and vessel optimisation in another 20 per cent saving. This leaves 40 per cent for eco-fuels. This is a much easier nut to crack, since their lower energy density often requires much more space on board a vessel.’
Combining wind propulsion technologies with secondary renewables such as 2nd generation biofuel (derived from waste), batteries, hydrogen or ammonia etc., and a suite of ship efficiency technologies can deliver significantly reduced carbon shipping, putting the industry on a path towards full decarbonisation, even under tight GHG emission reductions scenarios.
Project Unites Wind Propulsion and Hydrogen Generation to Create Fuel
Harnessing the power of the wind continues to be one of the technologies shipping companies are testing for future generations of ships. Some of the efforts are looking at traditional sailing or wind assistance as a propulsive force while others are seeking to harness wind energy as a source of stores power for vessels.
A new initiative is seeking to combine wind propulsion and hydrogen fuel to create a new generation of zero-emission shipping. The Wind Hunter Project will study combining wind propulsion sailing technology and wind energy converted to generate a stable supply of hydrogen.
Japan’s Mitsui O.S.K. Lines (MOL), which has already been exploring the use of wind sails, announced that it is leading the project along with others including the National Maritime Research Institute (NMRI), Graduate School of Frontier Sciences of The University of Tokyo, Nippon Kaiji Kyokai (ClassNK) and industry leaders in Japan.
The project will seek to combine sail technology with hydrogen carriers and fuel cells. Using power from the vessel’s turbine they will also seek to generate hydrogen with an electrolyzer. In addition to making it possible for the vessel to sail in periods of low wind, the project team plans to study the potential of supplying hydrogen generated at sea for onshore use.
During periods of strong wind, a power generation turbine will produce power by rotating turbines in the water. As such, they will be using some of the vessel’s propulsion to generate electric power. The electricity from the power generation turbine would in turn be used to operate the electrolyzer to produce green hydrogen. The vessel would also be equipped with hydrogen storage technology whereby the alloy would absorb and store on board the hydrogen produced during periods of strong wind. During periods of low wind, the storage alloy would release hydrogen to the fuel cells to power the ship and excess hydrogen not used during the voyage might be transferred to shore applications.
As a first step, the project team will conduct a feasibility study of the concept using a sailing yacht. They will seek to verify the function and performance through a series of cycle operations, i.e., turbine power generation, hydrogen generation/storage, and fuel cell-related propulsion. The next step would be a demonstration using a larger vessel.
In Dec 2021, Japan’s Mitsui O.S.K. Lines undertook the first tests of a program called Wind Hunter working along with a broad collaboration of Japanese organizations including ClassNK and academic institutions. Demonstration voyages were conducted using a sailing yacht, the Winz Maru, in Sasebo-city, Nagasaki in Japan.
MOL has already been actively pursuing the use of sail technology. In 2019, working with the Oshima Shipbuilding Co., MOL jointly obtained an “Approval in Principle (AIP)” from Nippon Kaiji Kyokai (ClassNK) for the design of a hard sail system. The system converts wind energy to propulsive force with a telescopic hard sail. MOL and Oshima Shipbuilding said they would continue to move toward a detailed design and implementation with the aim of launching a newbuilding vessel equipped with a hard sail as part of the Wind Challenger Project.
The Wind Challenger Project started in 2009 with the Wind Challenger Plan, an industry-academia joint research project led by The University of Tokyo. The project later gained the support of the Ministry of Land, Infrastructure, Transport, and Tourism and in 2018, MOL and Oshima Shipbuilding took charge of the plan playing a central role in the project.
The participants in the Wind Challenger project now include Ouchi Ocean Consultant, the National Maritime Research Institute (NMRI) of the National Institute of Maritime, Port, and Aviation Technology (MPAT), Smart Design Co., Graduate School of Frontier Sciences of The University of Tokyo, West Japan Fluid Engineering Laboratory Co., Nippon Kaiji Kyokai (ClassNK), and Miraihene Planning in addition to MOL and Oshima Shipbuilding.
The goal of the project is to complete the first stage of the testing, including accumulating and analyzing navigation data, to verify the performance characteristics of various equipment and the efficiency plant. These tests are scheduled to conclude by March 2022 and then they envision moving on to a larger 197-foot-long vessel by 2024. The goal is to have the system operational on a large ship by 2030.
WASP (Wind Assisted Ship Propulsion)
in Europe, the next phase of monitoring and evaluating wind-assist equipment is launching as part of the WASP (Wind Assisted Ship Propulsion) project. The goal of the project is to bring together universities and wind-assist technology providers with ship owners to research, test, and validate the operational performance of a selection of wind propulsion solutions.
Recently, the installation of two retractable wing sails was completed on a shortsea vessel operating between the Netherlands and the U.K. The 289-foot long Tharsis, operated by Tharsis Sea-River Shipping, was fitted with the units supplied by eConowind, which each measure approximately 10 feet by 29.5 feet. The wing sails can be folded into a specially designed storage unit and when in use they employ self-adjusting technology to maximize their efficiency in coordination with the vessel’s diesel-electric drive.
The installation of the wing sails was completed at the Neptune Shipyard near Rotterdam. The 2,364 dwt vessel was also fitted with an air lubrication system for its hull in 2020. That system was also upgraded during the recent drydocking.
“With this installation operating in both river and North Sea routing with varying winds we are eager to see how the rigs perform, especially with the unique combination of this self-adjusting technology in combination with a modern diesel-electric drive,” says Frank Nieuwenhuis, CEO of eConowind.
Over the next few years, Tharsis Sea-River reports the system will be tested and optimized as part of the WASP project. The expectation is that it will serve as an example of how wind assistance can help the shortsea shipping sector.
Wind propulsion market
The global marine propulsion engines market size was valued at USD 32.80 billion in 2020 and expected to hit around US$ 43.1 Bn by 2030, growing at a compound annual growth rate (CAGR) of 3.6% from 2021 to 2030. Based on product, the marine propulsion engines market is classified into the wind & solar propulsion engine, diesel propulsion engine, fuel cell propulsion engine, gas turbine propulsion engine, natural gas propulsion engine, steam turbine propulsion engine, and others.
The IWSA said that an EU commissioned report has outlined the potential wind propulsion market by 2030, which could amount to 3,700 to 10,700 installed systems on bulkers and tankers, associated with approx. 3.5 to 7.5 Mt CO2 savings.
A study was jointly carried out by CE Delft, Tyndall Centre for Climate Change Research, Fraunhofer ISI, and Chalmers University of Technology. IT found that Should some wind propulsion technologies for ships reach marketability in 2020, the maximum market potential for bulk carriers, tankers and container vessels is estimated to add up to around 3,700-10,700 installed systems until 2030, including both retrofits and installations on newbuilds, depending on the bunker fuel price, the speed of the vessels, and the discount rate applied. The use of these wind propulsion systems would then lead to CO2 savings of around 3.5-7.5 Mt CO2 in 2030 and the wind propulsion sector would then be good for around 6,500-8,000 direct and around 8,500-10,000 indirect jobs.
There has been a steady growth in market interest for wind propulsion solutions. This market interest has been driven by a number of key factors, including the IMO initial strategy on reducing GHG emissions in shipping by at least 50% by 2050, but also by market leaders taking zero emissions stances, including Maersk’s pledge to cut carbon emissions to zero by 2050.
Significant rise in sea trade and tourism is estimated to be a key driver of the global Wind-based marine propulsion systems market. Global sea trade as well as sea tourism has increased across the globe. This indicates a rise in the number of adoption of marine vessels. Rise in number of vessels is likely to fuel the demand for wind-based marine propulsion systems.
Governments of countries across the globe are enacting stringent regulations to reduce the emission of carbon and greenhouse gases. This is another key driver of the global wind-based marine propulsion systems market. Implementation of these regulations has compelled companies to look for more environmentally-friendly marine propulsion solutions. Thus, companies are now investing increasingly in the development of wind-based marine propulsion systems.
The global wind-based marine propulsion systems market can be segmented based on type and vessel type
Based on type, the global wind-based marine propulsion systems market can be divided into wing sail, kite sail, flettner rotor, and others. In terms of demand, wing sail and flettner rotor segments are expected to expand at a faster pace in the near future.
In terms of vessel type, the global wind-based marine propulsion systems market can be segregated into container ship, bulk carrier, passenger ship, defense vessel, tugboat & OSV, ferry, and others. Passenger ship and container ship segments are anticipated to expand at a fast-paced CAGR during the forecast period owing to the rise in demand for passenger ships and container ships across the world
The UK Government’s Clean Maritime Plan (released in July 2019), has assessed the global market for wind propulsion systems, and this is estimated to grow from a conservative £300 million per year in the 2020s to around £2 billion per year by the 2050s worldwide.
Many innovative wind propulsion technology concepts have been and are being developed for commercial shipping. However, none of the technologies has reached market maturity yet. Multitude of barriers that currently prevent the further development and uptake of wind propulsion technologies for ships; three key barriers thereby stand out:
- (Trusted) information on the performance, operability, safety, durability, and economic implications of the wind propulsion technologies.
- Access to capital for the development of wind propulsion technologies, especially for building and testing of full scale demonstrators.
- Incentives to improve energy efficiency/reduce CO2 emissions of ships.
This report was compiled in 2016-17 prior to much of the SOx regulation uptake and over a year before the IMO GHG initial strategy adoption. As it currently stands, there are a number of ready for market wind-assist technology providers in the retrofit market, with an increasing number of retrofit installations of proven rotor technology and test rigs and a growing number of other retrofit technologies and newbuild designs are in late stage R&D or moving towards sea trials.
As we approach 2020, there are significant market drivers that are will influence the price of fuel and the availability of compliant fuel worldwide. Oil prices have seen a drift upwards over the last couple of years with a subsequent gradual increase in bunker prices, the world sulphur directive will come into force in 2020 and could lead to a significant increase in costs either ULSFO, standard HFO + Scrubbers or a switch to either lighter distilates, LNG or other more costly fuels. The IMO has also sent a clear industry decarbonisation message with it’s agreement on preliminary GHG targets in April 2018, of at least 50% cuts (from a 2008 baseline) by 2050. This target may well be tightened further and a raft of short term and long term measures including some form of carbon levy or other market based mechanisms being introduced in 2023.
Allwright also sketches the market forecast and current status of wind-assisted propulsion. ‘By the end of 2020, 13 ocean-going vessels will be equipped with wind-assisted ship propulsion as well as over 20 small sailing cargo and cruise vessels. By the end of 2022, based on projects already announced, 47+ retrofit and new build vessels will be sea-trialling and in commercial operation next to over 30 smaller vessels.’ However, he expects new projects to be announced as well, meaning this number could grow considerably.
‘I see a change in how people in the boardroom see wind-assisted propulsion,’ states Allwright. ‘In 2014, people said “why should we do this”, in 2016/17 this changed into “how do we get it onto our ships?” And now: “our competitors are doing it, so we should look at it seriously”. Perception is that the cost of wind-assisted propulsion systems will go down, while fuel prices will go up. This will make it profitable.’
Allwright: ‘I expect the market for wind-assisted propulsion to double each year over the next 2-3 years.’ He also refers to the UK Government Clean Maritime Plan (July 2019), which estimated the market for wind propulsion systems to grow from 300 million pounds in the 2020s to around 2 billion pounds in the 2050s worldwide.
The possibility of mandated speed limits, an HFO ban in the Arctic and the further development of credible and viable hybrid wind and secondary renewable fuel solutions are also having an impact on the industry in it’s search for the next generation technology toolbox. With the development of innovative finance models, where CAPEX is reduced significantly or eliminated completely, there will be increased interest to utilise a technology segment that can deliver 5-20%+ reductions in fuel (and GHG emissions) for retrofit and from 30% and above for optimised new build vessels.
Global Wind-based Marine Propulsion Systems Market: Regional Outlook
Based on region, the global wind-based marine propulsion systems market can be classified into North America, Asia Pacific, Europe, Latin America, and Middle East & Africa
Rapid industrialization and modernization is estimated to boost the wind-based marine propulsion systems market in in Asia Pacific in the near future. China and Japan are the leading countries in terms of number of ships in the world. This trend is projected to continue during the forecast period. Increase in numbers of ships and rise in awareness about the environment are anticipated to boost the demand for wind-based marine propulsion systems in the region.
The market in North America and Europe are projected to expand significantly during the forecast period, due to the growth in number of passenger vessels and implementation of stringent governmental regulations on lowering carbon emissions and greenhouse gases in these regions
Key Players Operating in Global Market include: Eco Marine Power, Lloyd’s Register, BAR Technologies, Mitsui O.S.K.Lines, Becker Marine Systems, Advanced Wing Systems, Seastel Marine System (Shanghai) Co. Ltd., NayamWings, Wing Force Partners, AIRSEAS SAS
References and Resources also include: