Watts up and watts next?
The new era is now
For many decades’ ships have been operated on fuel oils with conventional propulsion system, contributing to large amounts of exhaust containing greenhouse gases and other undesired emissions. With an increased focus on emissions reduction, stricter regulations being enforced and sustainable operations, the maritime industry is facing changes in terms of what energy carriers and energy converters that may be used. How to face these changes have turned out to be challenging – maybe more challenging than anticipated.
There is currently no solution that may solely replace the fuel oils as the energy carrier with the same energy density (both volumetric and gravimetric). There are multiple options, including batteries, that may reduce emissions and result in more sustainable and efficient operations. However, there is no solution that fits all. If there had been, these changes would probably not have been that challenging.
Understanding the complexity
When batteries are discussed as an option for ships, the discussion tends to focus on whether it may be possible to have the ship run solely on electricity stored in the batteries. However, for most of the ships with batteries this is not the case. Close to 80 percent of the projects are hybrid and 20 percent are all electric.
There seems to be a lack of knowledge regarding what a battery may be used for on board ships. There are different ways batteries may be utilized on board ships such as optimizing the electrical grid on board, spinning reserve and peak shaving, immediate power, to harvest energy and backup power. Different ships have different operating profiles and the batteries must respond to specific energy and power demand. In addition, the desired/expected life-cycle of the batteries must also be considered. Electricity stored in batteries may for some ships be enough for the whole operation, but for other ships this will not be sufficient and additional sources of energy are required. Three examples are presented here:
Ferries (all electric where feasible): In general, the electric car/passenger ferries operate on fixed routes, close to shore, making the batteries a good business case with a fuel saving potential up to 100 percent. Batteries are used for the main propulsion of the ship, charging directly from infrastructure on shore. Currently about half of the ferries with batteries are considered all-electric, whereas the rest are hybrid.
Offshore supply ships (hybrid): Typically, the offshore supply ships utilizes the batteries for optimizing their operations on DP (dynamic positioning). The batteries work as a backup or a buffer for the generators, providing additional energy when needed (peak shaving and spinning reserve). This reduced the need for additional generator(s) to run on low load, which may result in a fuel saving potential of up to 20 percent. In his case the batteries are normally connected and charged by the diesel generators. The OSV battery projects are hybrid and represent a beneficial retrofit business case.
Bulk carriers with crane (hybrid): For bulk carriers’ crane system hybridization could be a beneficial business case, where the fuel savings potential may be up to 30 percent. There is large saving potential for e.g. cargo handling operations.
All three examples show the difference in operation, utilization, and reduction potentials. The main idea is to illustrate that it is highly important to understand what the battery is to be used for and how it is planned to be operated. In some cases, if this is not done properly, the outcome may be the opposite.
One trend going forward for newbuilds in the SOV offshore wind market is to be flexible for the future, with the potential for offshore charging, building them with DC-grid. The expectations around higher density of batteries and thereby possibilities for larger effects will probably make it easier and more cost effective to retrofit with a DC-grid aboard.
Another aspect that is very important is how the systems are operated on board. Sufficient training, level of competence and understanding of how to operate the systems are important both to prevent undesired events to happen, as well as how to act in case an incident happens. We see an increased focus on the importance of knowledge on the user side and implementation of good and safe routines of how to operate the batteries on board.
A huge potential
The number of ships with batteries are increasing. There are currently more than 450 ships with batteries including ships in operation and on order[1]. About 70 percent of the projects are newbuilds, whereas the rest are retrofits. In terms of number of ships car/passenger ferries, offshore supply ships and other activities are the ship types with most registered projects (see figure).
Batteries seems to be considered for ships with operations closer to shore, whereas there are still few projects for deep sea ships and ships with a less fixed operational profile. The past year has shown an increase of battery projects for various ships types, especially ro-ro cargo ships, cruise ships and fishing vessel in addition to the car/passenger ferries, offshore and other activities ships.
There is a huge unutilized potential for this industry. Comparing the battery fleet to the world fleet[2], the total number of battery projects (incl. on order) is less than one percent of the total fleet. We as a forum expect to see a further increase in the number of ships with batteries. The past years, we have seen an increase of the battery capacity on board the ships. With the development in battery technology, we also expect to see a further increase in the battery capacity being installed on board the ships.
The future is electric!
We are in no doubt that the future is electric and hybrid. Development of existing as well as new battery technologies with more energy dense batteries increases the possibilities for electric ships. Solutions involving combinations of low and zero emission technologies, such as batteries with e.g. hydrogen and ammonia, will be seen more and more moving forward. Batteries are needed for technologies that operate best at steady load like e.g. fuel cells, making batteries a natural combination with such technologies.
Regardless of what the future will look like, we believe batteries will be standard components on board most ships in the future. The type of battery and how it will be utilized on board will vary depending on factors such as operation profile, ship type and onshore infrastructure potential.
We as a forum we look forward to charging the industry with increased knowledge and experience to reduce uncertainty and participate in a way that it is done as safe and environmentally friendly as possible.
Collaboration is key
Even though batteries have been on board ships for many years, it is a continuous process to make sure they are operating in a safe way and that the risks for unwanted situations incidents are as low as possible. Unfortunately, the past year we have seen incidents involving batteries on board ships. In such cases it is highly important that the parties involved are able to collaborate and understand the core of what happened and why it happened, so that one can learn and improve. That way the whole industry can act and implement measures to reduce the risk for similar incidents to happen again.
Since the establishment of the Maritime Battery Forum in 2016, we have seen the value of sharing knowledge, experience and collaborate across company boards. This is something our members do, and we are impressed by the level of sharing. We believe it is one of the keys to succeed.
Our purpose is to promote battery-based value creation and make batteries a success within the global maritime market. Throughout our member meetings and annual conference, we meet to discuss topics that are relevant to the members and aim to discuss opportunities and challenges. To adapt to the pandemic situation we have, like many others, become more digital. We are meeting digitally through webinars and our next member meeting will be digital.
We are always interested in getting new members on board, and to expand. We are currently in the process of investigating options of creating hubs in both Asia and North America.
Let us know if you want to know more about the forum and how to join– check out our webpage: www.maritimebatteryforum.com or send us an email: director@maritimebatteryforum.com
Check out our ship register online:
Most of the information in our ship register is publicly available. We aim to cover the global battery fleet, relying on updates from industry players such as suppliers, integrators and operators. Are you seeing any missing project, let us know.
[1] From Maritime Battery Forum’s ship register (https://www.maritimebatteryforum.com/ship-register)
[2] Source world fleet: IHS Fairplay/Seaweb