SCHIFFSTECHNIK | SHIP
SCHIFFSTECHNIK | SHIP TECHNOLOGY Lars Ravens (eCap Marine) described recent developments for clean power Solutions for the maritime world. eCap Marine, a spin-off of wellknown Becker Marine, has focused in the past on clean in-port power supply from LNG delivered by barges to the ships. More recently, the engineering know-how has been applied to hydrogen packs for power generation and the conversion of small workboats and pleasure crafts to zero-emission propulsion based on hydrogen. Where some in the industry see problems, others like the eCap entrepreneurs see opportunities: »these [fuel] alternatives to the conventional solutions [..] do not necessarily have to mean additional challenges. They also open up prospects that were previously undiscovered or not considered as being interesting,« elaborated Ravens. A similarly optimistic note was struck by Jogchum Bruinsma (Nedstack), who presented a case study envisioning hydrogen as a fuel and fuel cells as realistic conversion option for a deep-sea drycargo vessel. The vision is not a pipe dream from the Netherlands but based on current R&D projects laying the foundation for a strong maritime hydrogen economy in the Netherlands, which focuses on smaller and short-term more realistic ship types important for the Dutch shipping industry: inland shipping new construction, inland shipping retrofit, coastal/shortsea shipping, passenger vessels and specialist ships. Strategic grand vision and tactical small-step implementation need to go hand in hand in the decarbonization journey. Decarbonization of shipping is progressing to ever more ambitious levels Fuel cells are more efficient than diesel engine gensets, and can run on a wide variety of fuels, including LNG, ammonia, and of course hydrogen. The two big advantages are high prices (which are expected to come down) and slow startup response (which is typically mitigated by also installing batteries to supply required extra e-power during start-up and power peaks). Both fuel cell technology and battery technology are evolv-ing dynamically, and installed power enjoys »exponential growth«, a term frequently »How do we fairly compare a larger set of energy saving options, which have different costs and different saving potential, which in turn may differ over time or for different operational parameters, and all that with typically limited information and time?« used at HIPER and after three years of COVID only too familiar to all of us. Syb ten Cate Hoedemaker (Maritime Battery Forum) gave an overview of the current status of maritime batteries and a bright future outlook. Prices continue to come down, and size and number of installations go up. The focus is on short sea shipping, such as ferries and work boats, which can recharge frequently and where the battery weight for the required kWh is not excessive. An example was the innovative © eCap Marine e-powered ice-breaker design with an unconventional asymmetric shape, presented by Thomas De Nucci (US Coast Guard Academy). The design reflects another trend due to global warming: As the Arctic ice continues to melt and waterways become more navigable, the demand for icebreaking services including channel clearing, search and rescue and vessel assistance will only increase. WASP Despite the summery temperatures in the Tuscan venue, there was not a single wasp seen. But everybody talked about WASPs, wind-assisted ship propulsion systems, de-noting collectively anything that harnesses the wind directly to save fuel on propulsion. There is a plethora of proposed WASP system designs, some with a long history, some still at the idea and artist-vision stage. WASPs have also enjoyed exponential growth over the past few years, not just in websites and publications, but also in installations. The basic idea is appealing, and the images catch the eye, but take-up of WASPs so far has been lagging behind the hopes of many in the community. Why is that? The question was discussed in the forum and at least some answers were given. WASP systems are treated by the industry like any other option to reduce the carbon footprint for ships, both on paper (what IMO credits for the EEDI/ EEXI) and in reality (what performance monitoring shows in terms of fuel saving over longer periods of operation). Energy managers in the shipping industry then look at business cases for their fleet and prioritize accordingly, and the finance sector, following the Poseidon Principles, does similar management by numbers. In principle, this is a fine modus operandi to decide on investments – and triedand-proven as our industry likes it. But for any WASP system, the business case is complicated. It may be very good, but comes with high uncertainty. Expected winds and operational speeds affect the resulting fuel savings in a highly nonlinear way – a factor 30 in the saved fuel is not impossible, to give an idea. But neither managers, nor bankers, nor IMO like an honest »it depends« answer in assessing fuel saving options. 58 HANSA – International Maritime Journal 10 | 2022
SCHIFFSTECHNIK | SHIP TECHNOLOGY For the EEDI, IMO has tried to simplify design assessment with a »wind matrix« to as-sume for a given design. The recently adopted MEPC.1-Circ.896 (77) EEDI Guidelines for Wind Assisted Ship Propulsion (WASP) devices updated the previous procedures allowing new, device-specific selection of wind conditions. The intent, no doubt, was good, but the effect may not be the optimum in adopted measures for the global car-bon footprint of shipping. Francesco Stella (Computed Wingsails) sees the latest IMO guidelines as a modern-day Aeolus Bag (as in Greek mythology Aeolus offered a bag to Odysseus to take his pick of favourable winds): »New EEDI scores seem to be skewed in favour of some WASP technologies, and not commensurate to expected, real fuel savings delivered by wind propulsion. This can favour the development of WASP devices that offer great EEDI improvements based on the regulatory selection of favourable winds, rather than on real fuel savings.« Green is Smart, Smart is Green Long-term decarbonizing shipping will require adopting lesser tried options including WASP and new fuels The example of the IMO WASP guidelines is just one incidence of a fundamental, larger issue. How do we fairly compare a larger set of energy saving options, which have different costs and different saving potential, which in turn may differ over time or for different operational parameters, and all that with typically limited information and time? The answer seems to lie in resorting to time-honoured strategies in design and operation of ships: use experience, condense it in software (in modern parlance meta-models) and live with good estimates rather than perfect accuracy. Frederik Gerhardt et al. (SSPA) proposed exactly that in their contribution »Levelling the Playing Field: A Numerical Platform for the Fair Comparison of Different Wind Propulsion Systems«, using extensively model test data. The purpose is to provide guidance for shipowners at the early concept stage of a vessel and help them select a system that suits their particular requirements. I guess the approach is the best we can do – for now. With time, we may get more insight into in-field performance of assorted green technologies for shipping, using performance monitoring and many ships, also before and after retrofitting. Josef Camilleri (Silverstream Technologies) presented pioneering work in this respect, for their air lubrication system, as such in-service demonstration of energy saving is vital for wider and faster adoption of the right technologies. »We believe that ship owners will welcome a more universal data collection method to evaluate and compare the different technologies available on the market,« explained Camilleri. An often-overlooked potential for significant fuel savings lies below the water in the biofouling protection – which should ideally be sustainable without biocides and effective over a long period, even at zero speed in port or when laid up. Ultrasonic biofoul-ing protection can be seen by now as a tried-and-proven technology for niche areas such as seachests and side thruster tunnels. But the market-leader Hasytec is ready to jump to the next game level. Xavier Mayorga (Hasytec) outlined the vision of ultrasonic antifouling for complete hulls of large ships, as targeted in the EU project CHEK for a bulk carrier and a cruise vessel, and the enabling technology which uses Artificial Intelligence in each sensor to optimize the parameter settings for actual ambient conditions, increasing the effectiveness of the transducer systems. Smart and green, indeed. And more ideas are waiting in the wings, ready to be tried out on ships. Philips and Akzonobel have developed an antifouling solution based on embedded foils emitting ultraviolet radiation; Fraunhofer, a method that irradiates fouling with blue lasers to clean hulls, destroying the fouling without damaging the coating. Visionary goals inherently come with the risk of overlooking the opportunities close at hand. Optimization is well accepted best-business practice already, so why not apply it to next-generation ship designs? The idea was obviously in the air, as presenters from three continents presented related work. Kenneth Goh (Knud E. Hansen) from Australia presented an innovative platform for optimising renewable energy (solar and wind) powered ships. Fabian Thies (Chalmers TU) from Sweden, hull form optimization for wind-powered and wind-assisted ships, and Ruben Paredes (ESPOL) from Ecuador, the application of formal optimization for a zeroemission high-speed craft for Galápagos inter-island service. Finally, the human factor in the decarbonization quest was addressed by Tracy Plowman (DNV), who presented effective digital training solutions to support the maritime decarbonization transitions, reminding us that we need to address awareness and expertise in the maritime community to enable the required changes towards decarbonization. The proceedings are free to download from www.hiper-conf.info. © DNV HANSA – International Maritime Journal 10 | 2022 59
