A new research effort is launching to study maritime battery
health as a means of building confidence and support the adoption of hybrid and
electrical systems in the shipping industry. While the shipping industry has
been slow to adopt battery systems onboard, having a better understanding of
the overall health of installed batteries and the available power is believed
will help to increase the adoption of these systems.
The objective of the DDD-Batman project is to develop
data-driven methods for diagnostics and prognostics of battery systems and to
provide methods for verifying the battery state of health (SOH) based on
real-time sensor measurements. Continuous operational sensor data of the
temperatures, discharge rates, voltages, and impedance behavior can be used to
model and forecast the degradation of the battery – showing the SOH at any
time.
The research institute Fraunhofer ISE will be leading the
project with participation from battery supplier Corvus, Carnival Maritime
GmbH, and DNV GL. The project is sponsored by MarTERA, an EU Horizon 2020
cofound scheme, aimed at strengthening the European Research Area (ERA).
“At the moment, vessels that depend on a Li-ion battery
system need an annual validation test of the battery’s SOH. At DNV GL we
require an annual validation testing of a battery’s SoH for ships utilizing
Li-ion battery systems for propulsion or maneuvering,” says Sverre Eriksen,
Senior Principal Engineer, at DNV GL – Maritime. “This can be quite time
consuming and has some limitations in the data we obtain. As batteries continue
to penetrate the industry, we need to improve the data we have, especially as
we see batteries in operation for longer periods.”
In addition to pure electric vessels, batteries can enable
significant gains in efficiency and emissions reductions in many ship types.
The goal of the DDD-Batman project is to develop better data on the health of a
battery system, enabling predictive maintenance strategies, and offering a
better look at the remaining useful life of the battery.
Removing the class mandated annual capacity test and
replacing it with an advanced analytical model using measured onboard battery
data as input will be beneficial to the maritime industry support the
development of new applications and confidence in battery systems. The
shipowner will no longer need to limit the vessel's operation to obtain a
validated SOH. They will also be able to better monitor and evaluate how the
battery is used and do needed adjustments which will save costs, provide
greater predictability for maintenance, and increase security.
Corvus believes that the results of the research will help
to automate existing processes. Improved operational data from the installed
base will also enable Corvus to further improve sizing algorithms and models to
more accurately predict how a change in the operational profile affects battery
life.
“The Costa group wants to take a further important step
forward along the path to emission-neutral ship operations by installing
innovative battery technology on board,” says Jens Kohlmann, Vice President
Asset Management Carnival Maritime GmbH. “In conjunction with Corvus Energy, we
are working on the use of lithium-ion battery storage systems onboard the AIDA
fleet.”
Carnival Corporation’s AIDA brand has announced plans to
outfit AIDAperla with a battery storage system with an output of ten megawatt
hours. It will be the largest system of its kind ever installed on a passenger
ship.
“The service life of battery cells has become significantly
longer in recent years. However, since battery systems are associated with high
investment costs and have to work reliably, precise state of health monitoring
and, ideally, extension of service life by adjusting the operating conditions
is of great importance. A major obstacle at present is that although some aging
processes are understood, their interaction, as well as measurement and
prediction during operation, are still a huge challenge.” says Maximilian
Bruch, a scientist at Fraunhofer ISE. “The targeted laboratory tests and at the
same time the analysis of load profiles and operating data in real use cases
make the DDD-Batman project an excellent approach to significantly increase the
precision and validity of online aging monitoring. In addition to the applied
development, the project contributes to the general scientific understanding of
battery aging.”
The project will collect operational data from ships in
addition to laboratory data and develop reliable and secure strategies for data
collection, storage, and sharing. The primary focus will be on battery systems
for cruise ships, including battery lifetimes, replacement strategies, life
cycle assessments, and shore connection procedures.
DDD-Batman is also looking to set new standards for
reliability and lifetime prognostics, deliver recommendations and give input to
standards, recommended practices, and class rules for batteries. The project
hopes to increase confidence in battery-powered ships, making batteries a more
attractive alternative and helping to enhance shipping’s uptake of electric
propulsion systems.