Vessel on the sea in night
Vessel on the sea in night

Energy efficiency developments on ship operators’ agenda

The industry’s ability to comply with the IMO’s 2023 energy efficiency measures demands accurate and proven performance management but there’s no quick fix.

This was the main message from the recent Hull Performance and Insight Conference (HullPic), organized by DNV and Jotun. The three-day conference was officiated by DNV’s senior project manager Volker Bertram and put the spotlight on the potential and pitfalls of performance management, which is increasing in importance due to the upcoming IMO energy efficiency measures.

“HullPic has its focus on insights into hull and propeller performance, using assorted sensor data, noon reports and increasingly machine learning to determine the current status of energy efficiency. With the IMO’s EEXI and CII measures coming into force January next year, the regulations will bring new levels of scrutiny to monitoring performance, tackling biofouling and reducing emissions. And that’s why it’s important for the industry stakeholders to get together to discuss the current practice and future challenges and solutions,” said Stein Kjølberg, Jotun’s Global Category Director Hull Performance.

Bertram said in the lead up to the conference that IMO is set to cut the carbon footprint of shipping and described the aims of the EEXI and CII. He highlighted that “Big Zero” is the long-term goal for the second half of the century, but the immediate next steps are EEXI and CII, mandatory as of 1.1.2023. EEXI is the Energy Efficiency Existing Ship (Design) Index, akin to the EEDI for newbuildings and is a technical measure. CII is the Carbon Intensity Indicator, an operational measure of carbon emissions per tonne/mile.

Under CII ships will be graded each year from A to E. Poor operational performance (E once or three consecutive years D) will require mandatory action to improve performance that will be audited in a SEEMP.

HullPic 2022 group photo
The three-day Hull Performance and Insight Conference was held in Tullamore, Ireland.

Uncertainty and anxiety ahead

Most of this is known already but not all has been decided.  Operators are hoping that the measures they are planning or have adopted will see them through, although there is uncertainty and anxiety ahead of their ships being given ratings. “Not every fleet manager will have straight-A scores for his ships. But forward planning and preparation will go a long way to ensuring the challenge is met. The 7th HullPIC conference did give some insights into the industry’s psyche in seeing the EEXI and CII writing on the wall,” said Bertram.

So, what can an operator do to improve its ships’ energy efficiency asked Bertram who, in answer to his own question, emphasised the speed reduction factor.  IMO gives some first pointers with its GHG studies and its GloMEEP website. Older ships were often designed for much higher speeds than used in current operation so Engine Power Limitation (EPL), whether by reducing fuel injected or by disconnecting a cylinder, is expected to be a measure adopted by many ships to achieve EEXI targets.

Alternatively, Shaft Power Limitation (ShaPoLi) uses torque monitoring and an additional control unit to ensure the power limitation. This has the advantage of being able to be overridden in an emergency. Furthermore, the collected data provides more performance monitoring insight according to Hauke Hendriks (Hoppe Marine) who shared the possibilities of ShaPoLi as an accelerator of telemetry installations within the maritime industry.

Moving from the engine room to the outside of the ship, better hull management and reduction of biofouling promises much for meeting the CII requirements. The Clean Shipping Coalition estimates that 10% of the world fleet’s fuel consumption may be saved through better hull management, which includes better coatings and cleaning strategies.

Considering hydrodynamic resistance increases around 7% - 10% each year with a commensurate increase in consumption due to fouling and hull roughness, there is huge capacity for improvement. Cleaning in drydock every five years, or sooner depending upon the operator’s maintenance strategy and selection of coating, temporarily restores performance. This gives the characteristic performance zig-zag curves for ships over time. Better hull management aims at smoothing the zig-zag curves through better antifouling solutions with less degradation in performance, and through shorter cleaning intervals.

However, as pointed out by Bertram most of the current crop of self-polishing copolymer antifoulings degrade rapidly with conventional cleaning, reducing their lifespan and leading to a need for re-application. The potential for energy efficiency improvements is there, but cleaning strategies need to be adapted to different (and for some operators new) coating systems.

Hull coatings can have a significant impact on CII

“Effective antifouling coatings is requisite in mitigating the impact of EPL on vessel speed and minimizing the increase in a vessel’s CII rating over the drydocking interval. A low performing antifouling can easily negate efficiency improvements delivered from costly investments into technical upgrades,” emphasized Sergiu Paereli (Jotun) who made reference to Jotun’s research paper on the impact of hull coatings on EEXI and CII. “Our findings are supported by vessel performance data analysed using the ISO 19030 standard. Wide commercial implications of both EEXI and CII further underscores the need for shipowners to make the right decisions on antifouling coatings. While EEXI compliance is the most immediate concern, decisions made now will have far reaching consequences on their businesses in the years ahead.”

Staying on the subject of coatings, Markus Hoffmann (I-Tech) described the impact of fouling idling on ship performance and CII. Referring to the company’s recent research and case examples, Hoffmann said barnacle fouling is still a problem for the majority of ships. “Idling is growing and increasing the fouling risk, leaving more ships at risk of the negative impacts of biofouling on ship efficiency and fuel use. Premium hull protection and proven biotech approaches are needed to combat the risks and meet the CII rating.”

“The better we are at detecting even small hull condition changes, the better we get at taking action,” said Falko Fritz (Albis Marine Performance) who highlighted the importance of using consistent performance data. “CII will push the use of proven energy saving technologies, including efficiency measures relating to hydrodynamics such as hull coatings, hull-form optimization and cleaning. Also, we firmly believe the importance of data acquisition on board and data handling on shore will increase going forward.”

Better insight leads to better decisions

The key word here is “proven”. Much of the discussion in the HullPic community is around reducing uncertainties for better decision making. Particularly around accurately predicting and verifying energy savings for assorted technologies so that they can be used for future decisions and for performance-based contracts such as between time charterers and owners. Richard Marioth (Idealship) made the point: “Monitoring per se does not improve energy efficiency, but insight gained from it leads to better decisions – better decisions in how to operate ships, for example”.

Better decisions through performance monitoring also applies to the assessment of energy saving devices and the best way to assess their effectiveness is long-term monitoring. But often ship owners don’t have the luxury of such experience with proven savings for their type of ships and operational profiles. In many cases, “it’s complicated”.

For propulsion improving devices (PIDs), such as nozzles, boss caps and fins intended to improve propulsive efficiency of the propeller, traditional model basin tests suffer from large scale-effects, as neither boundary layer near the propeller nor propeller rpm can be similar in model tests. Instead, computational fluid dynamics (CFD) simulations for full-scale conditions have become state-of-the-art in the industry.

“The new EEXI regulations and trends in shipping pressure ship owners to quantify the effect of these devices, giving rise to an uptake in CFD application for this purpose,” said Inno Gatin (In Silico), whose “Cloud Towing Tank” has been busy with such investigations for the past 12 months. He shared his findings in an attempt to draw general observations on the effectiveness of different PIDs.

While the CFD methodology is now mature, the actual assessment of PIDs is not. The industry still focusses on design conditions, in simulations and in sea trials for verification. This may be understandable in view of achieving a certain EEXI value, but for the larger picture, for reducing the long-term carbon footprint, performance in off-design conditions is key.

The issues become even more complicated for wind-assisted ship propulsion (WASP) systems. Under ideal conditions they will save fuel, but business cases and energy saving metrics require quantification, again not just for a design condition, but for a realistic operational profile. Sofia Werner (SSPA) gave a glimpse into the issues: “The number of [WASP] installations is predicted to increase rapidly in the coming years, and thereby the number of different technologies and makers. This development calls for standardised procedures for validating [WASP] performance in full scale but such standard procedures or guidelines are still lacking.” Her team proposes a methodology based on short sea trials, combined with performance modelling and statistical voyage analysis.

Still, business cases are by their very nature particularly difficult for WASP installations as both variations in operational speed and operational areas strongly affect the saving potential. As an example, a DNV study for a flettner rotor on a tanker showed a savings range of 1.4% to 41%. This is a handicap for vendors of WASP technology, but time seems to be on their side, and increasingly a broad spectrum of operational assumptions yields acceptable business cases.

Rapidly evolving field

Clearly with each passing year ship performance optimization continues to develop dynamically and improvements are being made using new technologies. This time round of lot of interest was shown   in AI and several presentations covered developments and collaborations in this fast-evolving field.  

Efthymia Ofelia Tsompopoulou and Vasileios Tsarsitalidis (DeepSea) shared findings on the evaluation of uncertainty of AI models for ship powering and its effect on power estimates for non-ideal conditions. DeepSea’s AI-model accuracy evaluation research represents a new benchmark in this growing sector and helps operators to understand and judge the real-world utility of AI in shipping.   

Casimir Morobe (Toqua) gave a presentation titled ‘Saving AI from the Hype: Getting real about the benefits and challenges of machine learning for ship performance modelling aimed at operational optimizations’. In his concluding remarks, Morobe argued “noon reports are not good enough. With good sensor data, AI is a big improvement.  However, good models should update over time, model all conditions and for all parameters. The real challenge is not AI, it’s operationalizing it in a reliable and cost-effective way”.  

Speaking on the sidelines of the conference, Darri Gunnarsson (Marorka) said shipping remains conservative and many feel noon reporting is sufficient or they fear systems will yield returns for charterers, not the owner. “But with changing regulatory and commercial pressures there’s now a growing interest in fleet performance management where they are able to see the benefits across the fleet. For sure real-time analytics of data is attracting a lot of attention, but at Marorka we firmly believe data collection is likely to remain a hybrid of manual and digital in the future”.

Collaborative projects

As in previous HullPic conferences, the collaboration theme also came through in a number of presentations at this year’s event. Malte Mittendorf (DTU) described the collaborative project titled ‘Performance analysis of a gas carrier using continual learning in a data stream context’. The study work involves DTU, Hempel and Wartsila and proposes an adaptive machine learning method for the assessment of the hydrodynamic behaviour of ships under realistic conditions, and for capturing the accumulation of biofouling. 

Vemund Svanes Bertelsen (Miros Mocean) described a new solution for how the impact from the environment can be separated from the technical performance of the vessel, together with some examples using data from real-life situations. The solution, developed in collaboration with DNV and the Copenhagen Commercial Platform, shows that accurate weather data can be used together with advanced models and accurate speed through water data to estimate real-time vessel performance with better accuracy than before. 

Irma Yeginbayeva (Jotun) also shared details on a ‘New measurement facility: enhanced skin-friction measurement over large scale plates in a channel flow’. The research project has been carried out in cooperation with NTNU and provides a better understanding of the hydrodynamic performance under various coating and application conditions. Future research work will provide support for internal numerical modeling studies and shed more light on the characteristics of complex turbulent flows over coated, aged surfaces. The experimentally obtained data will be used for full-ship simulations to calculate the impact of the different coatings for different ship hull models.

In a separate presentation, Solene Guere (Notilo Plus) focused on how real-life data can be used to improve hull performance.  She shared preliminary work findings on how machine learning and digitization techniques could be used to assist in hull performance reviews and predictions. “Digitalizing hull data can significantly improve fleet performance both in terms of reduced fuel consumption and emissions and opens a new world of opportunities to move from reactive hull cleaning to predictive maintenance”, she argued. “But this can only be achieved through a joint effort by the industry stakeholders to generate shared, quality data and link it to vessel performance tools. This will bring benefits for all the stakeholders and facilitate trust and transparency across the industry”.  

Commenting on reactive versus proactive hull cleaning methods, Simon Doran (HullWiper) said, “It appears that the industry is waking up to the biofouling threat to the environment and the overriding commercial benefits of a smooth biofouling free hull. An area of interest to us and one that is gaining traction is proactive hull cleaning and testing by an ROV has demonstrated this method can maintain fouling control coatings in a smooth and fouling free condition for extended periods without causing increases in the discharge of active ingredients into the water column. The challenge now is to maintain momentum with ship owners and operators to adopt the proactive hull cleaning approach”.   

Strong focus on CII

Much of the discussion at HullPIC centred on the CII. All details for the CII calculation (including details of interpretation by authorities) are not yet on the table, but heated discussions have already started. “The CII will be assessed on a yearly basis, but this may just be too slow in some cases to address corrective measures, for example in hull management. We need faster and better monitoring with early warnings allowing timely response, linking state-of-the-art performance monitoring to CII energy efficiency rating,” argued Bertram.

“Time charter contracts are likely to require a minimum C rating both at start and end of the charter. In any case, traditional charter party contracts need updating in light of the coming CII scenarios. IMO makes the owners responsible for the CII grades achieved, but the charterers make the operational decisions that ultimately decide the CII,” explained Bertram and added, “This ‘whipping boy’ scenario can only be managed by adapting charter contracts to align responsibilities and operational decisions. That we will see such changes is certain, how exactly we will draft and live such future contracts is to be seen. It is safe to say that discussions will continue well beyond 2023, and performance monitoring schemes will increase in importance, before finally leading to a shared, transparent and objective view of a ship’s performance”.

During a forum discussion session, the panel were asked if they saw a change in coating selection or cleaning strategies with the imminent introduction of CII. Carsten Manniche (UltraShip) said he thought that shipowners, depending on what kind of business they were in, would look at the five years docking interval. “I think it’s a good tool to adjust your CII based on what we can see at least. Also, I think there will be a strategy around how often and what you should do, and what kind of quality of antifouling you should use,” he said.

Martin Köpke (Hapag-Lloyd) said he thought the charter contracts will change. “Charter contracts are not my field, but on a personal level I would imagine there will be a clause in the time charter party contract that will take into account the CII rating. As it stands now, if you fail on a specific rating we don’t know if you get a penalty, we will see. It’s something that will need to be addressed by the technical department”.

Trial and error

Manniche also commented on time charter arrangements saying the owners or the managers (when a ship is under a technical management agreement) actions will in many ways be impacted by the charterers’ operational strategy. “It’s complicated, especially when looking at contracts in 2023,2024. I think it will be trial and error in the beginning, starting with the BIMCO contract so there’ll be some discussions I’m sure”.

Commenting from the floor, Aron Frank Sørensen (BIMCO) said the international organisation for shipowners and charterers is developing a CII compliance clause for time charter parties that was due to be agreed within weeks of the HullPiC conference.

There was also some debate in this session over the potential of a new matrix to calculate an environmental index as raised by Bas Blaak (Naviera Ultranav). Commenting on the initiative, Peter Lee (Oldendorff Carriers) said, “There’s been discussion on the new matrix, but it was concluded it’s not practical”.

Ivana Melillo (D’Amico) concurred saying, “I can support that comment about the use of a matrix in the EEXI and CII because if you compare not only the matrix as a formula, as a ship owner, we have to compare the use of this matrix in the different regulations. For instance, we have to compare CII in order to establish if our vessel is green for IMO market regulation or for ETS or for the taxonomy regulation or the Poseidon principles and so on. This is the problem for all ship owners, to define the use of the matrix considering the different regulations. For sure we understand the impact of biofouling management or other energy efficiency measures. But the problem is the investment, the stakeholder requirements, banks and so on, and also the real-life of the vessel which is completely different from the formula”.

Manniche added his view on the involvement of other stakeholders and said, “CII is not perfect for us to get an overview of how efficient we are trading our ships, but we have to acknowledge that it’s a regime that we have to move in. It also creates a value of CO₂ independent of fuel cost, because fuel cost and efficiently trading our ships that’s important. But now there’s also CO₂ and expectations from outside that we need to take into account in terms of the way we are operating our ships. And that’s a challenge”.

Sharing operational insights with the crew

It has long been suspected that performance monitoring feedback to crews also has an indirect training effect changing crew behaviour towards better energy efficiency. One of the highlights of the conference was the paper and presentation by Martin Köpke, with a detailed confirmation of the effect of sharing operational insights with the crew.

“In order to achieve a higher level of transparency and mutual understanding, Hapag-Lloyd introduced automated feedback to crews for all 250 operated ships. Each reported value is compared to an expected value based on a virtual model of each individual ship. This way the crew is immediately aware of reporting errors, measurement errors and possible excess consumptions,” said Köpke and added, “The initiative has been well received by the ship commands and crew who are able to see the impact of their own actions, compare themselves to peer vessels and, in turn, increase awareness to improve data quality and vessel performance.”   

Most stakeholders work hard together to get fit for the future to take these hurdles. But at the same time, another discussion is starting on whether it might be possible to take an easier route, trying to find some loopholes. For example, the EEXI like the EEDI is ship type specific. That makes sense. Container ships are slender and operate at higher speeds, bulk carriers are broader and operate at lower speeds. Let’s compare apples with apples, and pears with pears, thought the authors of IMO’s EEDI/EEXI regulations, using different baselines for required values for a given ship size. But what if you transported some containers on a bulk carrier and then submitted this ship as “containership”? This loophole can be closed by adding stricter definitions of the criteria for assigning “ship type” baselines to a specific ship, based on design and cargo records argued Bertram.

Potential loopholes

Or one can seek to exploit leeway in measuring and calculation procedures. For example, there is the discussion on the weather factor in the computation of the EEDI. The basic intent of the weather factor is good, reflecting ships usually operate not in sea trial conditions with calm weather, and that ships with lower energy requirements in realistic ambient conditions should be rewarded with a better energy efficiency index. The problem lies in the uncertainties in determining the speed loss in waves and the flexibility given in the regulations. Deliberately choosing assessment tool and calculation parameters in one’s favour could be used to improve the energy efficiency index on paper without corresponding improvement in real energy efficiency of the ship.

“Let’s be realistic. Shortcomings in details are not justification to reject IMO’s efforts to decarbonize shipping. Teething problems are normal. Awareness and open discussion allow timely responses to existing loopholes. The current state of energy efficiency assessment and monitoring is not perfect, but we have come a long way over the past seven years, when HullPIC started to bring together technology providers and users, and new challenges rather seem to fuel the dynamics in the community,” said Bertram.

Opinion poll reveals mixed opinions

A survey carried out at the conference by Richard Marioth (Idealship) showed that all the shipowners present had started preparations for complying with EEXI, with the majority saying they are almost ready to meet it. When asked how long it will take for 95% of shipping companies to assess hull performance through auto logging, five to ten years was the majority view, followed by longer than ten years. Between them, these two answers account for around 80% of delegates. Only a small number – but none of the shipowners present – thought this could happen in one to two years. 

Asked how shipping companies will mostly improve vessel efficiency in the next three years, almost 50% of those present suggested application of high performance paints at drydocking. Another 30% believed other options would be used, but around 15% believed that there would not be a lot of changes made.

As at the HullPic 2021 conference, attendees were also asked to rank in order of difficulty four challenges for shipping companies with regard to improving hull performance. There seems to have been a slight change of opinion as ‘Inaccurate Measurements and Analytics’ dropped from first place to third, while ‘Regulatory Compliance’ moved from second to first place although this time around this category was combined for EEXI and CII, whereas they had previously been separate choices. A new category ‘Uncertainty of Regulations’ made its debut and was ranked as the second biggest challenge by delegates. The choice of ‘Lack of Proven Retrofit Measures’ fell to fourth place.

Delegates were also given the opportunity of stating their own preference for new measures to recommend to IMO to lower carbon emissions. A fair number suggested a carbon tax, emission trading schemes or incentives for alternative fuels. Some suggested just in time arrivals or slow steaming or an end to rush and wait, which are variations on a theme. Not surprisingly there was also strong support for measures involving better hull performance and performance monitoring.

A question on how the CII will predominantly impact the chartering market saw almost 60% of delegates saying that the charter parties will be more transparent, while a little over 20% thought that charterers would only hire vessels with A-C ratings. Following on from that, almost half of the answers to the question, “What should be done for vessels with a CII rating of D or E for two consecutive years more?” said there should be more follow ups on improvement plans while around 18% wanted vessels to be stopped from operating and some 28% thoughts owners should be financially penalised.

In a final discussion session, delegates were asked about the way forward and key takeaways from the conference, including the use of AI and the ISO 19030 standard.

Soren Hansen (Navigator) said, “I think the ISO 19030 standard needs revision if it’s going to accommodate all the things that have been discussed at this conference. Then, if you are a service company providing performance services, what you need to do is to deliver something to the client that’s more precise, more precise predictions because that leads us to better analysis. But, again, it has to be proven and suitable for going into production”.

Malicious compliance

Giving a view from a shipowner’s perspective Anders H. Møller (MOL Chemical Tankers) said, “Part of the reason why I am here is that EEXI and CII were new to me when I came back to the operator’s side after five years working for a supplier, and I’m glad to see that I’m not the only one that thinks it is a little fuzzy. There seems to be a consensus, to quote DNV’s Volker Bertram, that all models are wrong but some of them are occasionally useful. I think we should expect to see a certain level of what I like to call ‘malicious compliance’ where some are operating to please the system, whatever system that is. At this conference I heard somebody mention that they are considering options to re-class vessels because it would give better correction factors. When that becomes a consideration, there is something wrong with the rules, and I think we need to look into that”.        

Ivana Melillo was another shipowner giving a point of view. She said, “I think the presentations have been highly relevant and covered a variety of technical and operational topics. I particularly liked the presentations that shared case studies relating to approaches on CII ratings. Today, we have just a general analysis coming from the guidelines by the IMO, we hope the updated guidelines will come in June. We need practical discussion because it’s important to know what we have to do, it’s important to know the rating of our vessels and it’s important to know how we can operate the fleet in cooperation with the charterers”.

Commenting on the conference overall, Wojciech Gorski (Enamor) said, “There’s been many interesting and insightful presentations which confirming ship performance optimization continues to develop dynamically. The fact that we cover many different approaches that aim to address common problems is inspiring in itself and clearly a collaborative approach will benefit the industry in the long term”.

Post-conference Jotun’s Stein Kjølberg said, “We get a lot of positive feedback on HullPic and that is reflected in the number of people who return every year to participate in the annual conference. We also think part of the success story is the fact that we have a good balance between ship operators, technology developers, equipment suppliers and data analysts. We meet to discuss developments and find common agreement on best practices and the way forward. Dialogue works.”

Driven by DNV and Jotun, with support from industry sponsors, the HullPic conference provides an opportunity for industry experts and practitioners to discuss and share advances, challenges and opportunities in performance management. This year’s conference was held in Tullamore, Ireland and attracted over 100 participants, many of them ship owner and operator representatives.

Morten Fon, CEO of Jotun at Nor-Shipping 2022

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