Saving energy and the environment with large energy storage solutions

Optimizing shipboard electrical power plants is a well-known challenge for many ship operators. Depending on routes and load profiles the requirements may change. An over-sized power plant consumes more energy, increases maintenance costs and affects the environmental footprint with excessive emissions of CO2 and harmful particle matter.

The challenge

The common way of producing energy on a ship is with several auxiliary engines (diesel generators) that are connected or disconnected to the grid as the power demand changes. Large diesel engines must be run at an operating point around 80-90% of the total capacity. If the engines go below this point, the fuel consumption needed to produce a certain amount of energy increases. This is the main challenge with traditional power plants.

Power consumption varies; however, it is very important to avoid the shutting down of the entire system because of a power shortage (black-out). Hence a ships power plant is often oversized and generators run at an unfavorable operating point or even idle, resulting in poor efficiency.

Loss of electrical power is especially a concern for passenger vessels traveling in narrow waters and archipelagos where safety cannot be compromised. Under these circumstances there must always be sufficient power for maneuvering of bow thrusters and a power loss can be devastating.
The issue is having sufficient power instantaneously, with high reliability on a favorable load profile to conserve energy.

This challenge is solved using new Energy Storage technology, combined with advanced automation. This makes it possible to supply large amounts of electrical energy to cover any peak demands and the inefficient use of diesel generators can be reduced.

Stena Jutlandica

Swedish ship operator Stena Line is currently developing a concept for their ship M/V Stena Jutlandica. The concept will utilize a Large Energy Storage System including automation and interfaces to the ships existing power distribution.

Concept development is in collaboration with system integrator Trident Maritime Systems (formerly, Callenberg Technology Group) and will be a “self-contained” solution including all essential components fitted into one container unit. The decision to make it containerized will give the option to move the whole unit to another vessel if the route or requirements change. Modular design also enables components to be replaced when new technology is available which makes the system sustainable for the future.

The unit will be located on the weather deck and have the capacity to supply up to 3,000 kW instantaneously and has an energy content of approximately 1,000 kWh.

The solution will contain all components required to be fully automated, including battery banks, converters, transformers and control systems. Peripheral equipment for safety, cooling and monitoring of performance is also included to meet requirements from classification societies and authorities.

Operational Considerations

During operation, the system is connected to the ships power grid, supplying power when needed, and when there is an over capacity in power production the batteries in the energy storage will be charged instead. When there is no need to run the diesel generator any longer, it will simply shut down. Thus, the number of diesel generators in operation during maneuvering (as an example) are significantly reduced and under some conditions it may be sufficient to only supply power from the Energy Storage. This process is most commonly referred to as “Peak Shaving”.

Ordinarily, a ship is also connected to shore power during port stay. This will give further reductions of emissions and simultaneously charge the batteries before the next voyage.

One consideration when installing an Energy Storage system onboard an existing ship is the modification and integration work needed to fit the new unit to the ships main electric switchboard. Redesigning, rewiring, software changes and new electrical switchgear upgrades are usually required to obtain the desired functionality. Furthermore, the design must consider failure mode operation and ensure a high level of redundancy. Performance should be monitored and in the case of malfunction in the Energy Storage system back-up power must be restored.

Based on the new technology available today, the way of generating electric power on ships can be significantly improved without compromising safety or operation. This results in reduced fuel consumption, less maintenance and more sustainable ship operation.

This project has been co-funded by the European Union and the Swedish Transportation Administration (Swedish Trafikverket).

EU co-financed project

How Callenberg Technology Group can help you

As a pioneer in the design and operational implementation of energy storage solutions, Callenberg can be a turnkey partner with you to support regulatory compliance and realize operational energy savings.