Which battery for your ship?
There are many solutions being explored to transition towards a (net) zero emission maritime industry. One solution that is increasingly becoming more popular are batteries, with already more than 1000 battery powered ships globally.
Solheim - babord (Photo Credit - Freudenberg E-Power Systems)
Batteries can be used for different applications on board ships, resulting in varying requirements for the batteries. Different lithium-ion chemistries and different battery system designs make it possible to find a suitable battery for different types of ships, using the batteries for various applications. But how do you know which is the right battery for your ship?
Always start with defining the operational profile for the batteries. Describe the different type of operations you want to perform with the vessel, and how the batteries will be used. Estimate the required power and duration for each operation to calculate the required energy from the batteries. If applicable, define multiple operational profiles, for example for normal, light, heavy, emergency, or secondary operations. More details in the operational profile will lead to a more accurate set of requirements for the battery system design.
There are 4 main requirements that you want to get from the operational profile. The minimum required energy that you will need to fulfil the operational profile as desired. This is considered as the available energy from your batteries at the end of life. The maximum required discharge power used to power your ship, as well as the maximum required charge power. Finally, the number of cycles that will be performed needs to be defined. There can be many different types of cycles, varying in size and duration. For an accurate lifetime calculation, the cycles need to be described clearly. Depending on your type of application it can be needed to describe the number of cycles per day, per week, or per year.
Alphenaar Moerdijk (Photo Credit - Zero Emission Services)
Next step is to determine the right sizing strategy. This is to make a first calculation of the costs, weight, volume, and expected lifetime of the batteries. Depending on the number and size of the cycles that will be perform it can be calculated for different battery types what the total installed capacity should be to reach the required lifetime of the batteries. Based on this total installed capacity the costs, weight and volume can be determined. Make sure that the battery system can handle the maximum charge and discharge power from the operational profile. Based on the results of this step, select the battery systems that fit your ship’s requirements the best based on costs, weight, volume, and expected lifetime.
The final step is to find the right fit, by looking at all the additional requirements and specification for the selected battery systems. Define the required safety systems to be installed in the battery space, such as firefighting systems, ventilation systems and gas detection. Make sure that the electrical specifications of the batteries match those of the other equipment on board. Make sure the voltage window, maximum charge and discharge currents, and other specifications are aligned. Compare the requirements for thermal management of the battery system. Some batteries require to be liquid cooled; others are air cooled. Onboard some ships it is also needed to warm up the batteries instead of cooling them. Make sure that the battery system installation is possible on board, considering the size and location of the battery space.
Always remember that all batteries are different, and each one of them fits with different types of applications. There is no such thing as the best battery system for all ships. With the speed of innovation that is happening on maritime battery technology, the industry is currently evolving. This can make the process of finding the right battery for your ship complex, but the Maritime Battery Forum strives to assist everyone by sharing knowledge and information.
Would you like to learn more about maritime battery technology and different sizing strategies for batteries used in various applications? Then the Maritime Batteries 101, an introduction course to maritime battery technology could be interesting for you. If you want to truly become an expert on maritime battery technology, then check out the 3 weeks online course offered by Greenectra.