How to define the operational profile for your maritime battery?
The process to determine the right battery for your ship starts with defining the operational profile of the batteries on your ship.
Sparky (Photo Credit Damen)
The operational profile determines what type of battery you need, how big it must be, and how long it will last. If you start with the wrong operational profile, you can end up with a battery that doesn’t perform well for your application, or one that is heavily oversized, making it more difficult for you to make money with your ship. But how do you define the right operational profile for your maritime battery?
There are 3 different types of battery powered ships: fully battery powered, hybrid, or plug-in hybrid. Fully battery powered ships only use batteries as main power source during their regular operations. Some fully battery powered ships have an emergency generator, or range extender. But if these are not used during normal operations, in general these ships are considered as fully battery powered as well. Hybrid ships use batteries to increase the efficiency of a propulsion system with another main energy source. This can be for instance a combustion engine, but also fuel cells. Plug-in hybrid ships are like hybrids, but with the additional option to charge the batteries directly with an external power supply.
Sea Trial (Photo Credit - REM Offshore)
There are (at least) 7 types of applications for batteries on board ships: full electric sailing, spinning reserve, peak shaving, load levelling, boost function, ramp support, and load smoothing. Full electric sailing can be done with all the 3 types of battery powered ships: fully battery powered, hybrid and plug-in hybrid. The other 6 applications are only possible with hybrid or plug-in hybrid configuration, when there is another power source on board the ship. The different applications are varying in power profile, time range and frequency, but all rely on the battery charging when the power demand is low and discharging when the power demand is high. All with the goal to increase efficiency, safety, redundancy, performance, and response time, and to reduce maintenance and fuel consumption.
The operational profile is expressed in power and time. The power demand from the ship in kW or MW, whatever is more convenient for the specific application. The time unit will depend on the type of application, whether it is seconds, minutes, or hours. Multiplying the power by the time will give you the energy required for the specific part of the operation in kWh or MWh.
Your ship might perform different types of operations or will operate under varying conditions. If applicable to your ship, define the operational profiles for these different operations or conditions. Besides the normal operations you can possibly have light, heavy, emergency, or secondary operations. And due to weather or current the operation can be in light or heavy conditions. Define what is applicable to your ship, and for what kind of operational conditions you want to make use of the batteries.
Stril Polar (Photo Credit - Simon Mokster Shipping)
Although it can be difficult to determine all the specific operations and conditions for a new ship, it is important for choosing and designing the right battery for your ship. More details in the operational profile will lead to a more accurate set of requirements for the battery system design. An accurate operational profile in the design phase will reduce the probability of an underperforming battery system.
The Maritime Battery Forum aims to assist everyone by sharing knowledge and information about maritime batteries. 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.