Containerised Battery Bank

Maersk to install a containerised battery bank on one of their container ships to test out the technology as a step in their quest to be carbon neutral by 2050:

Another Danish company is installing batteries on their new LPG/LNG tankers to be built in China:

Maersk and Tuntank is not alone in planning for the future reduction of GHG and the 2050 target of emission neutrality.
Another major player in the shipping world, K Line is joining 90 other shipping companies in an alliance to reach that goal:

But a battery is just an energy storage system, not an energy source. If you charge the battery using power generated using oil or coal, have you really saved the environment? What is the lifetime expected for these batteries and how will they be recycled at EOL? How much energy is required to manufacture them?

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Maybe you should read the articles linked to in this thread and several others about the use of batteries on ships and boats. All your questions have been answered somewhere in there.

Mr. Buggy, I went back and there are NO “articles linked to in this thread” that contain anything that answers ANY of the questions I posed. Indeed, they haven’t even told us what battery chemistry they are using! I am not talking about the benefits of LNG, etc. - I’m talking about these containerized batteries Maersk is proposing. If you have further information, please feel free to share (In English please, I’m an ugly American :slight_smile: )

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I was brewing up a quip about how much more useful it would be with a containerized LIFTR, but thought better of it. However, the discussion is pivoting in that direction, so there it is.

I’ll be the first to admit that I haven’t read every article you’ve posted on the subject, because holy shit the sheer volume (much appreciated, btw), and I guess some of those questions have been adequately answered. However, the rhetorical question pertaining to the energy source is a good one that is still standing as the elephant in the room where subsidies for Norwegian hybrid ferries get handed out. Sure, figuring out a working storage technology is an important step, but to imply that shifting ships to battery power would save the environment is also to imply that the world’s electrical energy needs have been solved without resorting to fossil fuels, and that’s… ludicrous.

My impression from a couple of usage cases is that hybrid power systems, either for propulsion or house loads, stop making sense when the power draw is great enough to provide meaningful load to a diesel engine. Last time I did the numbers it was still for lead acid batteries, and the while the recent shift to various lithium technologies have done much for the usefulness, I assume that it has made life cycle economy even worse.

The main reason why battery driven ferries are being adopted in Scandinavia, is the political will to combine stick and carrot at the cost of increased taxes and reduced effectiveness. I would think that Maersk’s main reason to experiment with a containerized battery bank is PR related, but who knows, there might be something I don’t see.

The energy required to move a box boat across the Atlantic is truly stupendous. The effective energy density of DFO (as measured at the shaft) is around 230 g/kwh. The electrical energy density of LiFePO4 batteries is 7.700 g/kwh, and then you subtract 10-20% conversion losses. If my math doesn’t fail me, that means the battery would have to weigh around 40 times as much as the diesel you’d expect to burn on the same run. Those of you who deal with such fuel oil quantities on a daily basis can tell me if you think a battery that size makes any kind of sense.

If I’m wrong, I’m ready to be educated, but could you then please post a link to a succinct and comprehensive source, preferably of less than 50 pages? Meanwhile, I think that the only realistic alternative for going carbon neutral in shipping is nuclear.


As the article on gcaptain notes, they will make use of a waste heat recovery system to charge the battery container.

A quick search of other articles pulls up the MHI system being installed on a bunch of Maersk vessels at construction . Here’s a link to some of those system configs and benefits:


Waste heat turbines make a lot of sense, and so does using a battery to absorb load peaks. My point is that ‘carbon neutral’ is very big talk, and batteries aren’t likely to be an instrumental part of any immediate solution.

As I have said many times before on this forum; Nobody is talking about propelling a mega container ship at 20 kts. across the Atlantic or Pacific using pre-charged batteries.
For that there are other non-carbon alternatives. Maersk is looking at several:

Others are looking at fuel cells and hydrogen and other options.

The battery banks are to store surplus power and use it at peak demand. On a container ship that may to feed reefer containers, or simply for hotel load etc.
For offshore vessels that is using DP and spend a lot of time idling in the field, this is were the savings comes.
In both cases it is initially to reduce fuel consumption and emission, until emission can be fully eliminated by other means.

The ferries in Norwegian fjords can operate 100% on electric power from renewable sources because it is short crossings and fast charging facilities are available at each stop, while the Color Hybrid use batteries to sail in and out of port and charge from hydro power in Sandefjord, while using surplus power from diesel generators and heat recovery to charge while underway. Battery power is also used to reduce peak loads on board.

I cannot find a single source to explain the working, pro and cons of having battery banks on board, but as more and more companies install them there must be a good reason, other than PR or being duped into thinking there are.

PS> Most of the ships that carries battery banks are called hybrid, not Electric.

I would think you are entirely correct in this thought.

This article has a better explanation than the Splash article.

The system uses waste heat to charge the battery and the power is used to augment the ship’s generators

It’s said to reduce maintenance on the generators as it provides both peak power for example when using the bow thruster and for redundancy. A lot of generator hours are run up just providing redundancy, for example the second generator that is run in pilot waters or the third generator run to supply power for peak bow thruster operation.

The WHB is putting excess heat into your CFW through the steam dump condenser, or you’re using your bunker tanks as steam dumps. Not as effective as one would like when the sea temp is 30 C.

Steaming at slower speeds (eco speeds) gives more steam. The more speed/load means more scav air which means cooler temps in your WHB.

Instead the excess steam energy is converted and stored in a battery bank that gets used for a bow thruster/big loads.

According to a Danish instructor (MAN class) I had, there is no such thing as “surplus power”. He said on the Triple-E class ship he sailed on, the steam created in the waste heat boiler was passed through a steam turbine generator. This produced not only enough power to carry this ship’s load (including reefers), but also sufficient power to feed into the propulsion shaft via a shaft motor/generator. This allows the same shaft RPM with a lesser ME fuel rack setting. A similar setup is shown here:

WHRS ST-PT.pdf (65.0 KB)

(This setup actually goes a step further and includes a power turbine right off of the exhaust manifold.)

There is no free lunch. If there is power being consumed to charge batteries then that power could be used to power other things which instead are having to be powered by the ship’s generators.

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At higher load it’s true that the TC is extracting more energy from the exhaust (and thus exhaust gas inlet temps to the WHB are lower), but the flowrate of gas more than makes up for it. (at least on my ship). This can be seen by the position of the steam dump at Nav. Full vs. some lower bell. Dump is more open at higher bells.

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This is very true and would be a very useful use for this system. Is there a CFR requirement to run two generators while maneuvering or is it just done because it’s the smart thing to do? If it is required, would a battery bank satisfy the requirement?

Look, I don’t need convincing. I already happen to think that hybrid power systems are hella cool, and even designed one or two, but that’s beside the point. Sort of.

I’m reacting to the ‘Together we synergize visions and technology to make the future carbon neutral, building a greener globe for the children of tomorrow!’ type of drivel that gets mixed in with the science. The notion that battery powered load peak mitigation has anything to do with going carbon neutral is utter bullshit.

In a word…No.


All of these feel good initiatives are dreamed up by public relations arms of these corporations to have a “green” message when challenged on what they are doing to combat climate change.

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I appreciate the input from several of you regarding how this battery is to be charged, and converting waste heat or other energy to electricity to be stored in the battery seems an excellent idea, albeit somewhat trivial in the big picture of powering the vessel.
It strikes me that none of the folks peddling batteries (in both land- and sea-based applications) seems to be even slightly interested in discussing the lifetime costs (both financial and environmental) of the things - as we all know, batteries are:
a) not forever - they wear out and must be replaced/remanufactured at some point;
b) consist of some quantity (usually large) of heavy metals, which are generally, if not universally toxic; and
c) have significant potential for “unplanned” energy release (see the Norwegian ferry story of a few weeks ago).

All of these things bear on the lifetime costs, and need to be included in any analysis - all the nice fluffy “eco-friendly” words to the contrary.