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WEBINAR: Hybrid and electric integration in the fleet

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Normally, when I start my presentations, I open with this dark, black slide, and ask: what do you see on the screen?

What I see on the screen is my bedroom at age 5 when I was scared of the dark. Because in the darkness, there are monsters. For shipowners, this is no different. Shipowners are also scared of the dark, because in the dark, you have new technologies, regulations, etc., that can alter the way you need to do your operations. My task is a bit like what my father did when I was 5, and that’s to cast a little bit of light on the situation, and show you that monsters in the dark are, in fact, not so scary, although we will be talking about batteries today.

So first, just a bit of motivation and why batteries.

Engines make noise. Batteries do not.

That’s the first start, but that’s not really why we’re working on batteries. For a luxury yacht, the noise is important. For a harbour, with people living in it, the noise is important. But we are talking about energy savings.

Batteries are a revolutionary new tech that has just been invented…?

At least that’s the feeling I get when I talk to a lot of shipowners, but in fact, looking at electric cars, people think that Nissan Leaf is a revolutionary car. In a sense it is, because it was one of the first modern electric cars. But looking back, the first cars were in fact electric, and preferred to be electric.

For example the Detroit Electric was produced between 1911-1916 with a range of 130 km with a nickel iron rechargeable battery. In the 1900’s, about 30% of all cars in the US were electric.


So batteries are not new. What is new is the technology we are talking about now and the applications in maritime. So lithium iron batteries are what we’re talking about in general, when we say batteries in maritime.

Greenhouse gas

Of course, greenhouse gas is an issue. It’s important to remember that battery is not a fuel, it is an energy storage. Hydrogen and battery are the only two sources that can get close to zero emissions, although it depends heavily on how you produce and how you recharge the battery and hydrogen.

If you look at other emissions like NOx, Sox, and particles – your local pollutants, if you like – compared to HFO, again, hydrogen and battery are the only ones that could go to absolute zero (again, depending on the energy mix used to produce it).


Another motivating factor is cost.

[This is a graph put together based on historic reports, and some live predictions.]

What’s important to note is that the light blue graph that goes down from 1600 and ends at 2025 is the old market prediction for battery cell cost. And a few years after that report was released, the dark blue line was the result, so the report shifted a little. The green cross at 2016 was the market leading price for this particular chemistry. (This is not a general battery cost; this is for a particular chemistry.) What is important to notice is whenever you read in the news, for example, that Tesla has a target to sell batteries for $100 per kW/h, and you think ‘oh wow, that sounds good, I want to use that on my ship’, please remember that that is for the battery cell, not for the battery system. So if you look at the battery system cost, which is represented by the black crosses and black lines, there is a wide range in the cost. This is also continuously being pushed down, so it is difficult to stay on top of the prices because the market is developing so fast.


What did you just see?

You just saw a 2-tonne family car destroy a Lamborghini in a drag race, but that’s not the point of the video.

The point of the video is, of course, acceleration. This curve is illustrating that, the measurement from a Tesla and a Dodge Hellcat. And the whole point of this figure is that once you flick the switch on a battery with an electric motor, you have instant, maximum torque. The mechanical system in the Hellcat takes some time to ramp up. And this whole [green] area between the graphs represents improved responsiveness, safety, and the potential to moderate the system – this is, to a large extent, why we talk about batteries.

On the one hand, there is nothing that beats batteries for efficiency. So if you can go all electric, for example with ferries, there is nothing that can beat batteries on efficiency.

However, when it comes to energy and range, currently there is nothing that can beat diesel, which is of course not good. So this ability to moderate the system represented here by Tesla and Dodge Hellcat is really what we will see the most of in the near future.

Batteries and hybrid systems represent a new way of providing power and propulsion

This fast response in the battery enables a bunch of benefits and possibilities.

For example, spinning reserve is a very interesting one. Typically, in offshore vessels, you have additional generators running just in case you need the extra energy. With a battery, we could rename the spinning reserve to a static reserve because the battery isn’t really running, it’s just there.

Same with optimising load. Having a battery that responds faster than the mechanical system means that you can let the mechanical system do what it’s good at and let the battery handle everything else.

Harvesting energy is a very interesting one for batteries. In electric cars, it’s really easy since whenever you are breaking or you are going downhill, you can regenerate power and recharge your battery. When you talk about vessels, it is a bit trickier, as the vessel isn’t always running uphill or always breaking in water. But if you have cranes or cargo handling equipment, or whatever where you can regenerate… Today we are wasting that energy, tomorrow we will be making good use of that energy.

So I will just quickly go through an example. This figure here is a power over time curve. It could be a load curve from a vessel manoeuvring in port; or it could be an offshore vessel in dynamic positioning; it could be cargo handling with cranes. The whole point is that it can be a varying load.

And if we bring up a typical fuel consumption curve for a diesel engine, you will notice that around 80%, which is a very typical optimal load point for a diesel engine, you are using as little fuel as possible to produce energy.

If we go back to our example and add a couple of lines, the green line represents the optimal running point for a fictitious diesel generator in this case. And the red line represents the maximum output from that engine. You’ll notice that the engine is never running at the optimal point of the engine – or at least close to almost never. And there are a couple of peeks that go above red. So the consequence is that we have to turn on another engine.

This means that on our fuel curve, we are not moving from 80% to 40%, significantly increasing our fuel consumption. However, if we have a battery that can respond faster than the system, we can allow the engine to run at the optimal load – the green line here. And anything above that, the battery will discharge, and anything below, the battery will charge up.


Let’s say that you have an offshore supply vessel. (This is an oversimplified calculation.) Then you have 4 engines, because that’s the requirement, but then you need that power available with relatively high fuel consumption (with 4 engines running). That is 9 tonnes of fuel per day and 96 hours of operation which goes on the maintenance costs.

But let’s say that we have a battery instead. So we can run one engine on 80% load which significantly lowers the fuel oil consumption. The result is that we can save about 18% fuel. But like I said this is a very oversimplified calculation. In real life, the results are showing 20-30% in dynamic positioning. In this fictitious example we are reducing 25% of the previous maintenance.

To make it simple, consider the system as a whole

Typically, when I work with companies that are interested in developing hybrid vessels with batteries, a lot of the time, they take a conventional vessel and add a battery. Sure, you can do that. But then you miss out on most of the benefits you’re not able to optimise in the best way. You are just adding a patch to a system that is not optimised in the first place. So make sure you start out with the full perspective. Consider designing around the battery, perhaps? Just make sure that you don’t do as you have always done because you will end up with what you have always had and an extra battery.

The fleet

There are quite a few different vessels.

There are quite a few car ferries, offshore vessels, a lot of passenger vessels, some yachts, some tugboats, and there is a lot of different stuff propping up.

There is so much going on in the world of maritime batteries – the uptake is so fast.

In the Maritime Battery Forum, we have a shipping register for battery powered ships – hybrids and all-electric. […] The total number of vessels including the orderbook is currently around 300 vessels, so it’s going up fast. If you do the math, you’ll see that the growth rate is around 30% per year in number of ships. In [terms of] battery size, it’s slightly larger than 30% but that’s mainly due to a lot of ferry projects realised in the past couple of years which have larger batteries than a lot of the other cases.

That being said though, there are larger vessels looking into double digit megawatt hour battery packs so the rate might even increase faster for battery capacity.

Country of operation

If we look at where they are, Norway, of course, is on top. Norway is being brought up quite often when it comes to battery powered ships due to a lot of incentives towards zero emission, particularly for ferries operating in Norway.

France has a lot of canal boats and also some other segments. Most of these are older vessels using lead acid battery technology but there are quite a few new developments, also.

Quite interesting – the USA is also in the top 5. One might not think that they would be high up on the battery power vessels, but they are actually growing quite fast. There’s a lot of interest in California and Washington. And it might surprise some of you to learn that the first all electric ferry in the US just started operating in Louisiana.

Newbuild or retrofit?

From a technology perspective, this could be quite interesting.

About one third are retrofits and the rest are newbuilds. In general, it’s easier to get a good integration if you do it as a new build, but there are also quite a few opportunities to improve so much that you might go for a retrofit of batteries.


There are quite a few different segments that are now working on batteries for their vessels. It’s not just ferries and passenger vessels, which is what I hear most frequently. [There are] lots of offshore shuttle tankers with batteries, regular tankers, product tankers, quite a few tugs. Currently there is a series of 4 tugs – all-electric – being built in Turkey. Naturally, it is interesting to have batteries on yachts. Aquaculture, cargo ships with cranes and so on, cruise vessels… Lots of different segments.

What you will notice is that with ferries, the retrofitting [figures] fit the previous figures nicely, with about one third retrofitted and the rest being new builds.

Offshore vessels, on the other hand, is perhaps the most interesting segment for retrofit. Since offshore vessels traditionally have so strict redundancy requirements that they are, from an energy production perspective, for a lack of better word, hopeless designs: lots of engines always running at low loads. Unnecessarily used, with unnecessary number of engines, if you have a battery. Only recently was the first retrofit done where they actually removed one generator and replaced it with a battery. For most of these retrofits, they have added a battery, and still, it pays off.


This slide shows the technology and how it’s being used.

Most vessels will be hybrid or plug-in hybrid. There will be quite a few pure electric vessels, although “pure electric” is a bad choice of words; all battery powered is more correct. For now, they seem to be the exception. So ferries, passenger vessels, vessels that have predictive operational profiles go all-battery. Most others will be hybrid where we combine battery and some form of fuel.

Perhaps more interesting than ‘will the future vessels have batteries’ is ‘which fuel will be supporting that batteries’.

The reason why we split between the plug-in and hybrid is simply because some vessels are meant for charging at shore and some are not. At the same time, I would advise not to use the figures absolutely, because quite a few projects don’t state if they are plug-in or not.

The figure on the left is to remind people that you don’t necessarily have to use the battery for propulsion. In the MBF (Maritime Battery Forum) ship register, if projects are ticked if they are meant to be used for propulsion or other. So if it’s meant for propulsion, it could also be used for other purposes on the vessel.

In this figure, “other” are gear bulk vessels or vessels with cranes.

Technology selection: Cell chemistry matters

There are quite a few different chemistries that we are talking about, and this is just a highlight of some of them. For example, the NMC chemistry is what’s being used the most in maritime at the moment. There are a ton of different versions of NMC, or NCM, chemistries, but the ones that are doing the most progress in maritime currently are NMC, which probably have about 75-80% of the market, LFP, which are iron phosphates and more or less cover the rest. And one technology that not many are using at the moment but will probably become a very interesting technology going forward, and that’s LTO, where we use titanate. This gives you higher power and lifetime capabilities, but also leads to increased weight and cost.


Of course there are quite a few ferries, offshore vessels and passenger vessels.

When I go around the world giving presentations, there seems to be this perception that everything is happening in Norway and Scandinavia. I would like to show – just briefly – what actually is the Norwegian share of these top ten segments.

Norway, currently, with the sailing fleet and order book has somewhere in between 35-40% of the fleet. But there is so much development happening in the rest of the world that this share of the market will probably shrink quite soon.

So what will come?

To me and the people I talk to, batteries will be a standard component in all ships. The question is who will be all electric? And those who don’t go all electric, what will be the hybrid configuration? Will we continue with diesel? Will we switch to LNG? Will we go all the way to zero – at least in operation and use fuel cells and hydrogen?

There are various requirements coming in: ECA zones, clean cities, sulphur cap, and lots of governments are focusing on emission, like the UN, and etc.

The cost focus will naturally not stop, but this is probably a key thing when we talk about batteries. Not always, but most of the time, batteries on new concepts lead to a higher investment cost. If you can remove engines and rearrange how you use your machinery, you might actually end up with a cheaper vessel than if you had gone for a conventional setup.

Customer requirements are also something that will be very important that drive the change. Just look at the cruise local pollutions.

All segments will develop quite fast. For obvious reasons, short-sea shipping, coastal fleets, and so on will be the first ones to adopt new technologies. This is simply because it is easier to set requirements for local authorities. Typical segments that will adopt batteries quite fast are fishing & aquaculture, work boats & patrol boats working in harbours. Most passenger vessels and ferries will be all electric or hybrid.

A lot more offshore coming on. What I didn’t show […] is that now there are several offshore rigs that are now considering and installing batteries. In short-sea shipping, in general, it is easier to adapt technology when you have shorter routes and local requirements, and basically any ship type that has redundancy requirements, for example a product tanker, when manoeuvring, can you switch off an engine? Can you remove one? For bulk vessels with cranes, [batteries?] will be a standard component – the business cases are quite outstanding.

To show the number of segments we currently have, I took an extract from our ship register. [There are] quite a few different vessels. It’s not only ferries; it’s not only passengers. Batteries are popping up in a lot of places. This information is available if you’d like to see it on a more regular basis. […]

Questions from the audience

What are the costs associated with the integration of this technology?

That’s a good question and a tricky question. It depends – which is my favourite engineering answer. The different chemistries have different costs, and it also depends on how you want to use the battery, which is why – I repeat – look at the system as a whole. A lot of the time when I talk to people wanting to do concept developments, they have this idea that they either run on batteries or diesel or LNG. It is important to understand that in a lot of cases it’s not ‘either / or’; it is a combination. Understanding that can reduce the battery size or increase, depending on what you want achieve.

Typically, what we see with costs is that you end up with a slightly more expensive vessel. Not by much. Or in some cases you end up with lower CAPEX. But then calculating the return on investment and looking at the total life cycle cost is quite important. […]

What would be the issues we need to consider around recycling?

It is actually one [question] that I get quite often: how environmentally friendly are batteries actually? On, we have a life cycle assessment of batteries in maritime, which shows that for ferries, it takes between 1.5 months to 11 months, depending on the energy mix, to pay back the emissions from producing the battery, relative to building a conventional ferry.


Then we get to the recycling questions, and there, we have a two-fold issue. Can we recycle the battery? The answer is yes, we can. Some of the battery suppliers showed me their certificates for recycling and they have a 97 rate percentage of the battery systems that can be recycled. So that’s quite good.

The second thing is that when you take a battery off the ship, like we are discussing with car batteries also, the battery isn’t necessarily spent. The battery can be used, it just doesn’t fit the ship’s operating profile anymore. So we’re also having second life discussions – what can we use the battery for? And then we have all sorts of issues like how do you make sure that the battery is safe? How do you balance it? Where should you use it? Who should handle it? The business case for that should be so good that this should work itself out quite nicely.

Most technologies indicate hybrid, but what about the fuel that is going to be used in conjunction with this?

I might not be the best person to answer, but seeing what is happening now with IMO2050, ECA zones popping up, sulphur cap, etc… Probably LNG will have a big role in this. We’ve been saying for quite a few years that LNG will soon take off, and now it seems that we’re actually at the point. We’ve been saying that for a few years, also, but now seems to be a good time, simply because diesel seems to be a dated fuel.

One of the ferry operators in Norway did a risk assessment on their fleet and they concluded that 80% of their fleet was running on the wrong fuel, and that was diesel.

It’s also interesting to consider fuel cells and hydrogen, but they are still in early days in maritime. There are a few projects going on, so I suppose we will see in five years’ time how the market develops and the technology also.

Additional questions from the audience

Can batteries be used in port to avoid burning fuels?

Yes, but depends on how long and at what power level. Normally this will require an “on/off” strategy where engine(s) run at optimal load handling hotel loads and charging battery, and when the battery is full, turn of the engine and run on battery. Alternatively, which is probably the better solution, is to have shore power available and balance with the battery.

Batteries and HK Convention on ship recycling? How does this go hand in hand in the future?

Batteries are recyclable, and there is so much value in them that this should basically handle itself. There are a number of recycling companies on the market. Perhaps more important; batteries that are taken off ships will probably have a 2nd life before recycling.

Sondre Henningsgård
Managing Director, Maritime Battery Forum

Sondre is the managing director for the Maritime Battery Forum, working with the member companies to make maritime batteries a global success. He holds a MSc degree in Naval Architecture, specialising in Marine Operations and Marine System Design and Logistics, from the Norwegian University of Science and Technology (NTNU). When not working in the MBF he is a discipline leader at DNV GL Maritime Advisory, working with energy efficiency and concept development, involving several battery hybrid feasibility studies.

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