Wind-assisted propulsion systems (WAPS) are increasingly recognized as a critical component in the maritime industry’s efforts to enhance energy efficiency and reduce carbon emissions. As Lloyd’s Register highlights, the integration of WAPS is not without challenges, primarily due to the industry’s limited experience with the technology and the lack of standardized methods for verifying fuel savings.
The adoption of these technologies is hindered by their varying stages of readiness and the industry’s unfamiliarity with them. The lack of standardised methods for verifying savings and understanding operational constraints, such as vessel speed and cargo capacity, further complicates their uptake.
The report title “Applying wind-assisted propulsion to ships” is a step towards addressing these challenges for existing ships, focusing on wind-assisted propulsion systems (WAPS). It provides an analysis of the current deployment, technology readiness, and potential hurdles for future adoption. This includes considerations of supply, installation capacity, safety, and regulatory frameworks.
Wind challenges
Notable challenges remain in the application WAPS technologies. First is the uncertainty around actual fuel savings, with no standardised criteria for validating savings claims. The potentially hidden costs around WAPS – including the full scope of engineering work and operational costs – also contribute to uncertainty around the business case. The ramp-up of the supply chain will be critical to meet rapidly growing demand. For technology suppliers to meet existing orders would entail them delivering around 2.5 times the number of units they have installed in the past five years. To achieve uptake on around 15% of the global fleet – as anticipated in the most optimistic forecasts would require a 75-fold increase on that level, requiring a dramatic increase in production capacity. Several suppliers are bolstering production capacity, but understanding how partners plan to deliver and maintain reasonable lead times amid the ramp up will be a crucial question for shipowners.
To date only around 16 yards have conducted WAPS retrofits, indicating that installation capacity needs to be far more widespread if future installations are to be met. While there are no showstopping capabilities for shipyards, planning projects will require careful consideration. One option considered is for a two-stage retrofit process, with WAPS foundations and cabling prepared during a scheduled drydocking – or even from newbuild – and the WAPS solution
itself attached during a second docking or, in some cases, during an extended port call. Optimising installation timing to meet regulatory emissions reductions or to maximise payback will require some consideration, as will the alignment of project schedules to component lead times.
While most technology providers offer optimisation solutions (and crew familiarisation with them), this is not universal. Shipowners preparing to introduce WAPS technologies should take as much care over optimisation as they do over the technology itself.
As a second thought, the complementarity of WAPS and voyage should be quite clear: technologies that depend on weather can improve their performance when vessels adapt their route to find the best weather. The scale of the impact, though, is more surprising, and is confirmed in multiple academic research papers:
- An Improved Ship Weather Routing Framework for CII Reduction Accounting for Wind-Assisted Rotors: Weather routing, speed optimisation and wind-assisted rotors produced 4.61%, 10.61% and 4.41% reductions in total fuel consumption respectively on a single route from China to the Middle East, with a similar reduction in the attained Carbon Intensity Indicator (CII).
- A New Routing Optimization Tool – Influence of Wind and Waves on Fuel Consumption of Ships with and without Wind Assisted Propulsion Systems: A new software tool showed around 4% savings on its own, but 50% when combined with WAPS.
- Minimal Time Route for Wind-Assisted Ships: A 76,000DWT wind-assisted cargo ship achieved a shorter crossing time, with lower fuel consumption and emissions, despite the longer optimised route planned by a weather algorithm.
- Weather Routing Benefit for Different Wind Propulsion Systems: Higher benefits from weather routing were found first for rotor sails, then for suction
wings, and finally for wing sails.
Wind assisted propulsion systems is in its late childhood and due to a significant growth spurt. The associated growing pains are inevitable. Lack of familiarity with the technology – not necessarily helped by multiple suppliers promoting many different systems – is one obstacle, both for shipowners hoping to retrofit WAPS technology and for the majority of shipyards that will be needed to perform those installations. Lack of standardisation of fuel-saving claims and methodologies for verifying them is another.
Both are in hand but will remain a challenge for early adopters. Despite those challenges, the significant impact of
harnessing the wind – on fuel cost, carbon cost exposure and environmental compliance – should not be ignored. And the indications are that it will not be. Projections are hard to ascertain but based on the best available analyses and the volume of feasibility studies being requested from LR, uptake of both retrofit and newbuild installations is poised for a sharp upward tick within the next two years.
