Periodic Reporting for period 1 - SEABAT (Solutions for largE bAtteries for waterBorne trAnsporT)
Berichtszeitraum: 2021-01-01 bis 2022-06-30
IMO targets 50% lower annual greenhouse gas (GHG) emissions from maritime transport by 2050 compared to 2008, and pursues efforts towards phasing them out entirely. Electrification (retrofitted/newbuilds) is one of the solutions to reach this target, and the market for electrified ships is large. 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, which may cause the capacities to reduce greatly over time. Therefore, batteries are oversized by a factor of 2 to as much as 10 to guarantee a specified capacity over 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 expected outcome is an optimal full-electric hybrid modular solution, minimising the battery footprint and reducing the oversizing (from up to 10 times down to max. 2 times), validated as a 300 kWh system (full battery system test) at TRL 5, and virtually validated up to 1 MWh and above.
A roadmap for type approval and a strategy towards standardisation for ferries and short sea shipping will be developed. The solution will deliver a 35-50% lower TCO of battery systems, incl. 15-30% lower CAPEX, 50% lower costs of integration and a 5% investment cost recuperation after the useful life in the vessel.
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 expected outcome is an optimal full-electric hybrid modular solution, minimising the battery footprint and reducing the oversizing (from up to 10 times down to max. 2 times), validated as a 300 kWh system (full battery system test) at TRL 5, and virtually validated up to 1 MWh and above.
A roadmap for type approval and a strategy towards standardisation for ferries and short sea shipping will be developed. The solution will deliver a 35-50% lower TCO of battery systems, incl. 15-30% lower CAPEX, 50% lower costs of integration and a 5% investment cost recuperation after the useful life in the vessel.
SEABAT so far has focused its work on three main elements:
1 Market Needs
The research analysis has highlighted a future cost target of the battery system for maritime use of approximately 250-300 € / kWh (complete system) with production volumes that should settle between 3 and 4 GWh per installation. Main bottlenecks for widespread implementation are: patents, certification for personnel, temperatures and humidity (especially in some regions with extreme weather conditions) and the consequences of external fire. Moreover, the main challenges, especially for the full decarbonisation, are: the cost of onshore energy, battery cost, specific energy and ageing and related replacement costs. Particular interest should be paid to possible recycling policies, in order to reduce the environmental impact of batteries and, at the same time, increase European independence from Asian countries for the raw materials necessary for the development of these systems.
2 Requirements
To understand the required performance of the product under development, it is important to know how marine battery systems perform that are currently on the market. Therefore, the performance of 30 marine battery systems from 15 different suppliers have been studied and reported. SEABAT identified 33 different battery properties, which can be summarized 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. These can be used to score batteries vs each other. As a conclusion of this research, we were able to identify 6 major different types of batteries: High energy, Medium energy or High power all either standard or heavy duty. The main type is determined by the maximum continuous C-rates of the battery system and whether or not it is heavy duty, is determined by the costs per cycled kWh.
3 Concept & feasibility study of 3 HESS topologies
Three HESS topologies with novel converter concepts were explained, 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
The evaluation and comparison of the HESS topologies is done via a generic optimization and modelling process. The inputs of the optimization are high-energy and high-power battery cell specifications, and the operational requirements come from 6 selected vessels. The output of the optimization is the optimal size of each topology per application for 10 years operational lifetime of the vessel. The investigated topologies are then compared against the baseline to the defined KPIs: total battery system cost; total battery mass; total battery volume; battery system losses and the required amount of components for each topology. Overall and compared to the baseline battery pack: Topology 1 typically scores better on all points. Topology 2 scores on average worse on volume, weight and amount of components and better on the rest. Topology 3 scores on average equal to the total battery volume and better on the rest. Consequently, the SEABAT consortium, together with its stakeholders, has decided to move ahead with Topology 1: Converter integrated into the battery modules.
1 Market Needs
The research analysis has highlighted a future cost target of the battery system for maritime use of approximately 250-300 € / kWh (complete system) with production volumes that should settle between 3 and 4 GWh per installation. Main bottlenecks for widespread implementation are: patents, certification for personnel, temperatures and humidity (especially in some regions with extreme weather conditions) and the consequences of external fire. Moreover, the main challenges, especially for the full decarbonisation, are: the cost of onshore energy, battery cost, specific energy and ageing and related replacement costs. Particular interest should be paid to possible recycling policies, in order to reduce the environmental impact of batteries and, at the same time, increase European independence from Asian countries for the raw materials necessary for the development of these systems.
2 Requirements
To understand the required performance of the product under development, it is important to know how marine battery systems perform that are currently on the market. Therefore, the performance of 30 marine battery systems from 15 different suppliers have been studied and reported. SEABAT identified 33 different battery properties, which can be summarized 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. These can be used to score batteries vs each other. As a conclusion of this research, we were able to identify 6 major different types of batteries: High energy, Medium energy or High power all either standard or heavy duty. The main type is determined by the maximum continuous C-rates of the battery system and whether or not it is heavy duty, is determined by the costs per cycled kWh.
3 Concept & feasibility study of 3 HESS topologies
Three HESS topologies with novel converter concepts were explained, 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
The evaluation and comparison of the HESS topologies is done via a generic optimization and modelling process. The inputs of the optimization are high-energy and high-power battery cell specifications, and the operational requirements come from 6 selected vessels. The output of the optimization is the optimal size of each topology per application for 10 years operational lifetime of the vessel. The investigated topologies are then compared against the baseline to the defined KPIs: total battery system cost; total battery mass; total battery volume; battery system losses and the required amount of components for each topology. Overall and compared to the baseline battery pack: Topology 1 typically scores better on all points. Topology 2 scores on average worse on volume, weight and amount of components and better on the rest. Topology 3 scores on average equal to the total battery volume and better on the rest. Consequently, the SEABAT consortium, together with its stakeholders, has decided to move ahead with Topology 1: Converter integrated into the battery modules.
The ambition is to design, test and validate a novel scalable and modular battery concept for the maritime industry. In the project, 2 battery strings will be built and combined in a battery pack. Each string contains a set of high-energy and high-power modules. The high-energy modules contain battery cells with a low C-rate, low cycle life and high energy content, while the high-power battery modules contain battery cells with a high C-rate, high cycle life and low energy content. Three architectural principles were researched and compared . All three went beyond SToA and results have been published. These analyses were based on market understanding and overall requirements, which are very relevant to anyone working on batteries for the maritime industry and publicly available on our website. Current work addresses the physical realization of the various battery modules, such that simulation results can be validated. The outcome of the overall research shall be a significant step towards electrified ships, which on its turn will drastically reduce (greenhouse gas) emissions. The research strengthens Europe’s knowledge on batteries and strengthens the industrial network to design, produce, (re)manufacture, install, deploy and recycle them.