Periodic Reporting for period 3 - SEABAT (Solutions for largE bAtteries for waterBorne trAnsporT)
Reporting period: 2024-01-01 to 2025-02-28
The International Maritime Organization targets 50% lower annual greenhouse gas emissions from maritime transport by 2050 compared to 2008, and even pursues efforts towards phasing them out entirely. Electrification (retrofitted or newbuilds) is one of the solutions to reach this target, and the market for electrified ships is large. However, the technology is not yet mature and batteries for maritime use are considerably more expensive than automotive batteries. Ships are built in small series and the battery solutions are typically bespoke, leading to low economies of scale and high assembly costs. On top of that, the battery systems that are used, are not specifically designed for maritime applications. A single type of battery is used for both high-energy missions (e.g. for maintaining cruising speed) as well as high-power peaks (e.g. fast charging, manoeuvring). However, a single battery technology cannot cover all the necessary requirements. The result is that the selected batteries cannot be used in their optimal working point, causing rapid capacity reduction and thus oversizing to guarantee a battery lifetime of ~10 years. The oversizing brings high costs, which are an important barrier to increase the market share of electrified ships. The challenge is to substantially reduce the cost of large waterborne transport battery systems.
The overall objective of SEABAT is to develop a hybrid energy storage system (HESS) based on:
(1) modularly combining high-energy and high-power batteries,
(2) novel converter concepts to facilitate the above and
(3) production technology solutions derived from the automotive sector.
A modular approach will reduce component costs (battery, convertor) so that unique ship designs can profit from economies of scale by using standardised low-cost modular components. The hybridization ensures that not only the amount of modules but also the overall electrical properties (e.g. required energy and power) can be tailored to the ship. The concept is suitable for existing and future battery generations and high-power components that may have higher power densities or are based on different chemistries. The outcome is an optimal solution, validated as a prototype at 246kWh and upscalable to 20MWh. TCO savings up to 60% are possible, based upon maximally 80% lower CAPEX, 80% lower cost of integration at the ship yard and 30% investment cost recuperation. These numbers are highly dependent on the use case and all maxima may not occur at the same time.
Finally, the project ralized a roadmap for type approval and a strategy towards standardisation for (among others) ferries, tugs, and short sea shipping.
The overall objective of SEABAT is to develop a hybrid energy storage system (HESS) based on:
(1) modularly combining high-energy and high-power batteries,
(2) novel converter concepts to facilitate the above and
(3) production technology solutions derived from the automotive sector.
A modular approach will reduce component costs (battery, convertor) so that unique ship designs can profit from economies of scale by using standardised low-cost modular components. The hybridization ensures that not only the amount of modules but also the overall electrical properties (e.g. required energy and power) can be tailored to the ship. The concept is suitable for existing and future battery generations and high-power components that may have higher power densities or are based on different chemistries. The outcome is an optimal solution, validated as a prototype at 246kWh and upscalable to 20MWh. TCO savings up to 60% are possible, based upon maximally 80% lower CAPEX, 80% lower cost of integration at the ship yard and 30% investment cost recuperation. These numbers are highly dependent on the use case and all maxima may not occur at the same time.
Finally, the project ralized a roadmap for type approval and a strategy towards standardisation for (among others) ferries, tugs, and short sea shipping.
SEABAT has generated a module design that was manufactured in a high energy and high power variant. The modules have been integrated into a system and performance tested. This validated design is based on market needs, requirements and a thorough concept study. Following list containes some of the concrete project results:
1) The research analysis has highlighted a future system-cost target of approximately 250-300 € / kWh with production volumes that should settle between 3 and 4 GWh per installation. Main bottlenecks for widespread implementation are: patents, certification for personnel, temperatures, humidity and the consequences of external fire. The main challenges are: the cost of onshore energy, battery cost, specific energy, ageing and related replacement costs.
2) The performance of 30 marine battery systems from 15 different suppliers has been studied and reported. SEABAT identified 33 different relevant battery properties, which were grouped to 9 topics: costs, energy, power, lifetime, thermal management, safety, ease of mechanical integration, ease of electrical integration and the capabilities of the battery management system.
3) Three topologies were explored, evaluated, and compared towards a baseline state-of-practice mono-type battery topology: (1) Converter integrated into the battery modules, (2) Switching between individual cells, (3) Partial power converter integrated into the battery modules. Topology 1 was deemed most performant and developed further in the project.
4) Each component has then been designed, procured and/or produced, including: module DC/DC converter & controller, string inductance & controller, casing, BMS slave & master, cooling plate, thermal management, and master controller. EMC analysis and performance validation was performed to confirm proper operation.
5) By using techniques from the automotive sector, SEABATs production line is capable of (in term) mass producing the battery modules. The current prototype line produced 3 modules per week, including validation. During the assembly preparation phase, an extensive analysis of the interfaces took place, covering mechanical, electronic, thermal, and communication aspects. The assembly process’ flow diagram and assembly steps were written out, along with the identification of de-risking measures for the module assembly process
6) A dedicated test setup was designed and a detailed testing sequence was followed. Some design challenges were identified, but the overall functionality including hybridization and modluarization have been proven to work. Finally, a roadmap for type approval was initiated.
The key exploitable results include
1) A validated hybrid and modular battery system model, that can be used to virtually design and benchmark SEABAT's solution to the state of practice
2) Three hybrid energy storage models, including a descrete battery system design, that offer alternatives to the selected hybrid battery systems
3) A validated battery mangement system design, that can be used to control and monitor a battery during its lifetime
4) A detailed cost and sizing optimization routine, to quantify potential cost savings. A limited version of this tool is publically available at battery.flandersmake.be
Plenty of the research results in SEABAT are openly available: 10 open-access and peer-reviewed papers were published. The final newsletter includes a summary of the takeaways of the project. All this information is available on the website.
1) The research analysis has highlighted a future system-cost target of approximately 250-300 € / kWh with production volumes that should settle between 3 and 4 GWh per installation. Main bottlenecks for widespread implementation are: patents, certification for personnel, temperatures, humidity and the consequences of external fire. The main challenges are: the cost of onshore energy, battery cost, specific energy, ageing and related replacement costs.
2) The performance of 30 marine battery systems from 15 different suppliers has been studied and reported. SEABAT identified 33 different relevant battery properties, which were grouped to 9 topics: costs, energy, power, lifetime, thermal management, safety, ease of mechanical integration, ease of electrical integration and the capabilities of the battery management system.
3) Three topologies were explored, evaluated, and compared towards a baseline state-of-practice mono-type battery topology: (1) Converter integrated into the battery modules, (2) Switching between individual cells, (3) Partial power converter integrated into the battery modules. Topology 1 was deemed most performant and developed further in the project.
4) Each component has then been designed, procured and/or produced, including: module DC/DC converter & controller, string inductance & controller, casing, BMS slave & master, cooling plate, thermal management, and master controller. EMC analysis and performance validation was performed to confirm proper operation.
5) By using techniques from the automotive sector, SEABATs production line is capable of (in term) mass producing the battery modules. The current prototype line produced 3 modules per week, including validation. During the assembly preparation phase, an extensive analysis of the interfaces took place, covering mechanical, electronic, thermal, and communication aspects. The assembly process’ flow diagram and assembly steps were written out, along with the identification of de-risking measures for the module assembly process
6) A dedicated test setup was designed and a detailed testing sequence was followed. Some design challenges were identified, but the overall functionality including hybridization and modluarization have been proven to work. Finally, a roadmap for type approval was initiated.
The key exploitable results include
1) A validated hybrid and modular battery system model, that can be used to virtually design and benchmark SEABAT's solution to the state of practice
2) Three hybrid energy storage models, including a descrete battery system design, that offer alternatives to the selected hybrid battery systems
3) A validated battery mangement system design, that can be used to control and monitor a battery during its lifetime
4) A detailed cost and sizing optimization routine, to quantify potential cost savings. A limited version of this tool is publically available at battery.flandersmake.be
Plenty of the research results in SEABAT are openly available: 10 open-access and peer-reviewed papers were published. The final newsletter includes a summary of the takeaways of the project. All this information is available on the website.
In the project, 2 battery strings were built and combined in a battery pack. Each string contains a series of respectively 12 high-energy battery modules respectively 12 high-power modules with integrated DC/DC converter. The high-energy battery modules contain battery cells with a low C-rate, low cycle life and high energy content (NMC), while the high-power battery modules contain battery cells with a high C-rate, high cycle life and low energy content (LTO). The amount of modules per string determines the maximum output voltage (up to 1500V), the amount and type of strings then determines the maximum power and energy. SEABAT’s battery modules are rated for maritime use, with an innovative casing, thermal management, power management etc. A sizing tool and cost/KPI evaluation tool are available to optimally scale the battery.
The innovations mentioned above have been proven in simulation and validated in the lab using Power Hardware In The Loop tests. The outcome of the overall research is a significant step towards electrified ships, which on its turn will drastically reduce (greenhouse gas) emissions. Furthermore, the research strengthens Europe’s knowledge on batteries and strengthens the industrial network to design, produce, (re)manufacture, install, deploy and recycle them.
The innovations mentioned above have been proven in simulation and validated in the lab using Power Hardware In The Loop tests. The outcome of the overall research is a significant step towards electrified ships, which on its turn will drastically reduce (greenhouse gas) emissions. Furthermore, the research strengthens Europe’s knowledge on batteries and strengthens the industrial network to design, produce, (re)manufacture, install, deploy and recycle them.