5 Myths with Electric Propulsion: Don't Believe Marketing
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- čas přidán 22. 08. 2024
- Electric power and electric propulsion are still growing industries for yachts and small ships. In this field, a few marketers may stretch the truth a little to make a sale. This led to many myths and misunderstand about electric propulsion. Today I debunk five common myths.
Note that this video does include several simplifications and details not covered for brevity. For full explanation, commission a custom engineering analysis from DMS.
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References
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All good points. Battery is overall useless for boats/ships, except for ferries. I am certified on a few here in Norway and they sure are amazing machines.
What I would disagree in your video is complexity. With modern equipment, batteries are actually quite simple .They are different but there are almost no moving parts, no oil changes, no leaks, no fumes, almost no maintenance. You need some controllers to supervise the battery with loading or discharging but that's it. Also modern Li ion batteries are holding up fantastically for the absolute abuse they get on our ferries. We charge them with up to 4 MW every 30 minutes but they barely degrade.
The major downside is simply the range, that's why all Norwegian ferries that have plug in electric systems (about 64+) only one is without combustion engines. All other ones have 2 backup diesel generators to help when power is low, converting them to peak shave diesel electric propulsion systems.
That's a good point. I see it as an increased complexity more due to the associated systems in a smaller vessel. If we are just talking about straight electric propulsion, I agree that they are equal to engines in complexity. But with small ships, I see people integrating electric propulsion, diesel generator, shore power, solar charging, recharging from using propeller as a water turbine, etc. That complexity isn't inherent to electric propulsion. But I see that electric propulsion allows us the opportunity to explore the increased complexity and provide a more flexible power plant. (Granted, much of this only applies to small ships and yachts.)
For a lot of small yachts there will be a solar setup with storage battery anyway. Making it 10x bigger just changes the physical size of the parts rather than adding more complexity. But comes with the advantage of being able to run induction cooktops etc so you may not need gas for cooking any more. Then it comes down to whether you have a generator at all. But even if you do, the difference between "we're under power so we're putting hours on a fossil engine" and "it's been six months, we need to start the generator" is significant. "Sailing Uma" don't have a generator, "Rigging Doctor" do, for example.
But for commercial operators you're going to need something, whether a nuclear plant or a diesel one (FWIW nuclear are almost all nuclear-electric systems, so you've talked around those boats)
@@DatawaveMarineSolutions why do you say that an electric engine has more complexity? an internal combustion has a lot more complexity and parts and even more complicated electronics.
this is a good video from an Engineer about the environmental differences between Cars but much should apply to boats czcams.com/video/6RhtiPefVzM/video.html
There are disadvantages to Electric engines and batteries but it does not help your argument if you invent reasons without backing them up.
@@akcarlos I like Engineering Explained (EE) but I don't think that video applies to boats. For one, boats not only have to push through (well, most of of the boat) a medium 1000x denser than air, it also has to work against wave drag especially at higher speed. This means that even a few increase in weight means that the consumption increases by a larger factor than in a land vehicle. Also, remember that on larger land vehicles, the problem of the larger battery becomes an issue. See EE and even thunderf00t's video on the Tesla Semi
As for complexity, he probably meant the control system. Sure, a combustion engine is complicated but you only have to control it. With battery propulsion, you got to do energy management with hotel loads which is complicated. More so for hybrid systems.
you missed the obvious. you dont use batteries, you use a generator to make the power. makes it a modular system that doesnt have to stop for maintenance when combined with battery. easier to accomodate in the vessel as components arent required to be all in the stern, silent when needed like steaming at night, you can run multiple systems from the battery storage, bow thrusters etc. many benefits.
I watch many sailing channels on CZcams and observe that sooner or later every one has problems of some kind or other with their diesel engines . While this makes entertaining viewing is it the best method of propulsion for a sail boat? Combustion engines are highly complex with thousands of different mechanical and electrical parts. There is so much that can go wrong and inevitable they do even though they are being regularly maintained. An electric motor has very few moving parts and much less that can go wrong. A BLDC electric motor has basically two bearings at each end of the shaft for moving parts and not a lot else. In contrast a diesel engine has pistons pounding up and down, bearings, gaskets, hoses, cables, pumps, filters, cooling, alternator etc all of which sooner or later will fail. A diesel engine requires regular maintenance whereas an electric motor requires minimal maintenance.
For me an important factor is that once on an ocean passage you cannot stop mid ocean and top up the fuel tank. With electric there is usually a daytime charge from solar especially in the tropics and probably regeneration from sailing if on longer passages. If range is a problem than just add more battery capacity and more solar. I agree lead acid batteries are heavy but lithium are not. If a boat goes to electric drive it makes sense to replace the batteries with lithium and use some of the space and weight gained to increase the battery capacity.
Depending on the size an electric motor it can often be lifted by hand and is much lighter that a diesel engine. In contrast look at some of the videos of people removing a diesel engine from a boat using all sorts of lifting tackle to get it out safely. Removing the engine and diesel tank will not only reduce the weight of the boat but provide additional valuable storage space as a bonus.
To me it looks like going electric is a win win situation and that is before adding the benefits of silence, no fumes, no dirty bilge, no smoke and no smell.
An all-electric system has many drawbacks, and I think you're operating off a few false premises.
For example: size and weight. While electric motors can be lighter than ICE options, we need to compare apples to apples. There are also ICE engines that can be picked up with one hand (think RC car engines), but they don't do us much good for powering large marine vessels. Similarly, the motor in my washing machine can be picked up with one hand, but is not useful for large marine applications.
The comparable performance electric motor is going to also be heavy, just like the ICE engine it's replacing. It might be a bit lighter, but we're talking in the same order of magnitude. The real benefit here is that electric motor form factor means we can decouple our sources of power from our use of power (more applicable in hybrid systems than all electric, but still holds true).
Next, I want to address your battery statement: batteries are heavy. Lead acid batteries are heavy, but also lithium batteries are heavy. The problem lies with energy density: various lithium chemistries are extremely high in energy density and discharge capacity, but no matter which chemistry you look at, they all pale in comparison to hydrocarbon fuels. This means we need lots of batteries to give us similar ranges as a much smaller weight in hydrocarbon fuels.
This is one of the limiting factors in the EV market: the range cap that everyone is running into is defined by size and weight. These modern EVs are using the best lithium chemistries available, and still fall far short of the range and refill capability of hydrocarbons. No matter which battery chemistry you use, you have the unavoidable fact that you do not consume the weight of your energy storage as you use it, and while the cheat code appears to be using batteries structurally to squeeze more capacity in, that introduces a whole different set of nightmares for safety and maintenance.
Additionally, lithium battery tech presents a set of hazards that do not really exist with hydrocarbons like diesel (especially in applications where we are sitting in highly electrolytic mediums like sea water). Lithium battery fires are incredibly difficult to manage, and they present a fume/explosive risk that is a poor companion for metal compartments strengthened by sea water.
The point of all this rambling is to say that while batteries can make a good emergency or standby store of energy, they are a very poor means of primary storage for large scale or long distance travel applications.
The best solutions involve carrying your fuel in sources that are much higher up the density graph: uranium, hydrogen, and hydrocarbon liquids being the obvious contenders.
Nuclear electric hybrids are obviously the best but not currently feasible for anything but large naval vessels for a variety of reasons.
Hydrogen fuel cells are theoretically great but not commercially ideal and seemingly won't be for a while longer.
This leaves us with liquid hydrocarbons. Diesel electric hybrids are already in use in everything from rail and marine to over-the-road trucking (newly in this arena) because of the safety, efficiency, power, speed of refill, etc.
Hybrid systems are probably the best of all worlds. Using the electric drive for slow maneuvering and idle is really efficient where the dirty diesel engine is extremely inefficient. But the diesel is really good for sustained 60% loads. This method does not add too much battery weight.
The biggest advantage to me: huge house battery.
For a video that purports to disprove myths, this certainly seems to intentionally walk right by the reasons why people choose to go electric, the sorts of boats being made electric, and the economics behind going electric. You imply that most people converting are doing so because of their concern for CO2 production, when very few people I'm aware of really care much about this issue. I mean, you know, we all want to do our part, but that's not what's driving us. We're changing because as recreational sailors and cruisers we are tired of the complexity, maintenance and expense of diesel power. Diesel's great, when it works. When it doesn't work - which is often - it's a royal pain. Mechanic's time, when you can find them and get them to come, costs a fortune. The engines are enormously heavy and located in cramped compartments and it seems that the part you need to get to is always impossible to get a wrench on. For every green warrior converting to electric to save the planet, there are five people who decided to go electric after hanging upside down trying to bleed the injectors while bobbing around out there, or spending two hours hanging upside down over the back of the engine block trying to replace another damned belt that shredded. The engines are dirty and noisy. The fuel is increasingly expensive, and finding decent diesel in some places is difficult. And when you get a bad batch in the Bahamas or Lewards you're dicked. And when your engine decides to have a fuel issue it always seems to be someplace dark as you're going into a channel with wind against tide. I like being able to simply push the throttle and feel the boat move. You talk about electric adding complexity. This is simply ludicrous in the real world. Diesel motors, especially the newer ones, are hugely complex with multiple potential points of failure. Electric motors have very few moving parts, and the components that run them are quickly and easily interchangeable because they are easily accessible and don't weigh much. Electric motors are torquey and deliver umph way down in the rev curve and they are extremely reliable. The only disadvantage to them, honestly, is range. Shrug. Some of us are still actual sailors. We sail. And your comment that running solar slowly doesn't have the math behind it is absurd. KWs are KWs, and if I have more coming in than going out, I can do it practically forever. For free. The cost of repowering with a new diesel is prohibitive. A new electric motor with battery system and inverter and charger will run less than half the cost of a new Yanmar. For a power boat electric makes very little sense (outside of narrow niches like canal boats). But I think that most people going electric are sailors. For us there are significant advantages you are ignoring.
Indeed - you hit the nail square on the head !
Electric is more complex to people who haven't dealt with them before, but infernal combustion has a lot more moving parts and needs a lot more servicing. Especially in small boats where changing oil and fuel filters etc is a hassle because they don't have full time mechanics on board. The maintenance schedule for an electric motor is "make sure it's still there" rather than the long checklist for a diesel.
Now all we need is a battery with the energy density of diesel...
Or a small battery and a large hydrogen capacity, you loterally are surrounded by "fuel" and with sufficient solar and wind energy generation its a cheaper option in the long run
@@victormiguelmontero136wind is actually the most expensive way to generate electricity, it only affordable due to the government subsidizing it.
Electrical engineer, So many things wrong here. I can't even begin to be bothered starting . Some one please help me out here
A electric motor that's heavier than the engine it is replacing lmfao. Grin Technologies just did a sailboat where they replaced a 300 lb boat engine with a 10 lb electric motor with the same power.
yes, this part of video made me wonder what kind of electric motor heavier then diesel. If you add battery weight then it may be same as diesel engine+fuel tanks or even more depending on battery capacity.
less maintenance for electric is also a big deal.
But the biggest advantage for me is to be able to be off-grid with solar+LiFePO4. You cannot generate more diesel out of thin air if you are in the middle of nowhere and need fuel to run generator to power fridge/frizer/AC/etc. Many boaters need no diesel generator if enough solar&LiFePO4 on board. But still, it's nice to have it as a backup.
I think the biggest mistakes when considering electric boats is that all boats are still made as if they are using ICE engines. Few are getting to innovate the marine space like Tesla is the automobile and SpaceX industries.
Instead of treating batteries as if they are replacing a fuel tank, design batteries as part of the superstructure itself. Any weight batteries add is minimized as being part of what holds boat together. Why, rely on solar to charge batteries when you can also have wind turbines. You can also use aquathermal energy (same as geothermal) to generate electricity from the difference in temperature between the water and air, which would be perfect for a constant trickle of energy always going into batteries. Further, when anchor or docked you can lower small turbines into water columns or tides and capture energy from there. Lastly, there's the ever present kinetic energy from waves. Just like how sidewalks are designed to capture energy from people footsteps, the hull can be designed to capture energy from the water making contact. If there ever was a more perfect solution for self sufficient travel it's the marine sector, it just requires thinking outside the narrow box of historical boat production.
Nobody is gonna burn 36 hours at wide open throttle. You are gonna burn your engine. Compare both at 3-5 kw for 12 hours and you'll see
direct drive only works for lighter craft with lower power requirements..
the more weight you have to push, the slower the prop needs to spin to couple with the surrounding water under those loads.
that said, not all electric motors are created as torque equals ... the axial flux pancake motors put out more torque per volt.
For electric motors, their power is equal to voltage times current. A high voltage motor will run faster but has small torque and vice versa. Joule heating is related to the current. Hence, a high speed motor stepped down via gearing is preferred to a slow one
And their torque scales with weight, so a high speed low torque will be lighter than a low speed high torque.
I'm waiting for solid-state batteries... and millions of dollars. 😆
I'm totally imagining Galaxy Quest with Tim Allen shouting keep the boost on for "Peak Power"
wait but when a car says "200hp" or whatever that too is peak power; if you ran that engine at peak power RPM and full throttle you'd get a very reduced lifetime. Also yeah power is power, but in many cases the availability of max torque at any RPM makes vehicles accelerate harder in the real world. "holeshot" with a jet boat for example is easy to do with electric torque and can bog down an equivalent hp ICE engine.
Enjoyed your video, really valid points. I sell electric motors & batteries and we often tell people that there are parasitic loads on smaller motors (
I want to say that is not true, because I would like to believe that all engines report a true and accurate rating of their power. But I'm sure some manufacturers cheat the system a little. They should be reporting "brake power" on the engine. That would be the power output, with all the extra loads like alternator and water pump that the engine needs to keep itself running. "Brake power" comes from testing the fully assembled engine on a dynamometer and measuring the power output from the shaft. But, I'm not an engine manufacturer, and the cynical part of me suspects they find ways to adjust the numbers slightly.
As to the flatter electric throttle / torque mapping, not sure. In theory, a digital throttle can always be smoother than a menchanical one, simple because we can program the digital throttle to account for changes of the torque curve. But that's not strictly electric motors. I have also seen this behavior on larger outboards that now include digital throttles.
@@DatawaveMarineSolutions Thanks for taking time to reply. Another thought is that certainly 'repowering' with electric is rarely practical, since old hulls, old tricks, high drag. Too many issues for private owners to stomach. But for new builds & hulls built for purpose? Perhaps there's a future there for Naval Architects in that specialty. I worked on a Oram 62ft cat that could reach 10kts on only ~10kw. it was only 8T which helped. Makes for a cheap system, I think there'll be some narrow band of private usages/vessels that work.
@@brentsinger1980 That is very true. I have worked with a number of clients designing new hulls for electric propulsion. The biggest difference: I spend a lot of effort to keep the drag as low as possible.
It seems like most comments here are referring to blow boats. Every blow boater I know brags that he isn't burdened by fuel range or mechanical failure (as they repair a mast, sail, or rigging from storm damage) so why is it you all seem so concerned about propulsion? You say you don't need it but you act like you can't live without it. No way on Gods green earth that I would attempt to cross the Gulf Of Mexico or even Lake Michigan with only battery power. No mater what kind of batteries and on top of that I would feel very much safer sleeping on top of a tank of gasoline than the type of batteries needed for this type of operation namely lithium. A pontoon boat with electric power on a small lake or pond? Sure! The amount and size of batteries for this could be setup to easily scuttle them if needed. It would be fun and advantageous for just putting around and just cruising and socializing. No mater what many of you think electric cars have major problems and putting those problems on a large pleasure boat would be problematic at best and possibly life threatening in several different ways.
Good video. You mention "increased complexity" with electric propulsion. Currently, for all practical purposes absolutely - but this is only because diesel engines are so incredibly reliable for so long (Yanmar is over 100 years old). Everything taken together a battery electric vehicle is mechanically simpler than an internal combustion engine vehicle. (This is part of the reason why I drive a Tesla to my sailboat that has a diesel engine.)
And it's great to see the CO2 'footprint' compared. 10% of a diesel's. (I've heard otherwise intelligent adults 'explain' how a Tesla pollutes more making the batteries, than their Ford F250 diesel could ever do....)
What I've deduced from the current electric boat motors is that they seem to be sub par what they could be. Yes, the weight of the batteries and range mean you will have less energy stored on board, and a weaker electric motor extends that range, but it seems to me (up until a year or so ago,) the electric motors available for sailboats were less capable than they could be.
Gearing an electric motor shouldn't be a problem. Otherwise my Tesla would only drive at 350 mph. The electric motors in my Model Y have high torque at 1 rpm and a top speed of 6000 rpm with almost constant torque across the entire range. (This is why EVs will replace not only ICE cars, but diesel trucks. On land of course. My Model y weighs 4400lbs, double any other car I've owned.) Obviously it's not that difficult to gear down this output to the ideal propeller rpm.
None of the sources I've followed have ever claimed that solar panels can supply enough energy to keep an electric drive going continually. (Maybe some seller has made this claim. Yes, it would be wrong.) There are a couple of very large power cats being offered for sale that approach this....but they would run slower.) Speed is indeed safety to get out of or away from trouble (unless you have 4 of them, they all say 300HP, and you're drunk. )
The video I'm looking forward to is the one on hybrid power. When I bought a Prius, even before I was interested in sailing, my second thought was 'This would probably be great in a boat.' And as an old sea kayaker I know that quiet on the water has huge pluses. Animals come closer, I'm more relaxed. An electric motor in the drive train could be a (short term) safety factor for bad fuel, clogged injectors, etc... It would be nice to enter and exit a slip or an anchorage quietly and without the stink. (I've never understood how Beneteau/Jenneau can make such nice boats, but they're diesel engines are always the loudest. I've got a 20 year old Hunter that by comparison just seems to purr. Same Yanmar, but better sound proofing. Because of the density of water noise is 5 x louder underneath the boat than on the deck.) Cheers.
I agree. The hybrid options have me the most excited. I saw one option from Hybrid Marine UK (www.hybrid-marine.co.uk/). And just recently, I noticed the big engine manufacturers are starting to hint at options that look like hybrid propulsion.
@@DatawaveMarineSolutions Cool. I admit I'm a huge Tesla fanboy. But I feel for Toyota's churlish attitude about battery electric vehicles. I've also got a Prius V - it's a wonderful, reliable, efficient, car. Toyota won the hybrid, invested hundreds of millions in factories and foundries, was positioned to make billions -- and then along came Tesla.
It's probably like making the perfect carriage and then Ford comes out with the Model T. I doubt the marine business would be big enough for Toyota, but I'll bet they could make a terrific small boat marine hybrid (especially if they partnered with Yanmar.)
@@DatawaveMarineSolutions Hybrid is a more complex case to optimise since the balance of ICE power, fuel tank, generator capacity, electric propulsion motor power/torque, battery bank size, power output all have to be balanced for the use case. Oh ya, and you have to make the ICE and Electric work with the same prop.
@@WillN2Go1 There are a lot of crazy people who do engine swaps from boats to cars and vice a versa. I think it would need a larger engine and be a smaller vessel but someone may do it at some point on CZcams.
A Volvo Penta D4 diesel engine weighs more than i.e. a VW 82kWh battery pack and in boats the weight isn’t always an issue. The weight can actually have a positive effect on seaworthiness.
Can have a positive effect, well on most boats it’s not. But well some build a stainless steel binimi as an addition.
Obviously that’s not making the boat a better sailer too. 😂
What about the flat torque curve of electric motors and only high rpm power on diesel motors?
Thanks for this. While it seems much of the numbers are based on current tech, where is the future? I love the idea of electric motoring using solar, albeit the slower pace (6nmh). How many knots would ten 400w panels provide for an unlimited range depending on sunlight for a 35’ cruising e-boat (e.g., a saxdor 320gtc with an extended roofline)? Distance desires, combustion requires route detours and refueling at very hight costs and there’s maintenance and noise pollution. The solar catamarans like soleil seem quite interesting, but 55’ is too much boat for me.
Some of the more interesting technology for near future: ammonia or methanol as replacement fuels for diesel. Both fuels have two important traits. They can be stored as a liquid near room temperature. (Ammonia requires mild refrigeration or compression.). And the molecules contain a lot of hydrogen atoms. Both options still require more development. But the goal would be to use these in a hydrogen fuel cell and power electric motors with the fuel cell. Then we don't need huge batteries.
Power is power, yes, but power/torque curves can be different for the same power. Electric motors tend to reach max power at lower RPM than ICEs, which may or may not be a good thing depending on the application.
With regards to direct drive. Electric motors can be built to run efficiently at a wide range of RPMs. Optimizing for low speed generally come at the cost of larger size, weight and cost. I do agree, usually a smaller faster motor with a gearbox makes more sense.
I think as the technology stands today, electric propulsion mostly makes sense for sailing vessels, which usually need ballast anyways, and vessels that are intended exclusively for sheltered waters, where 4kts is a perfectly viable speed in the vast majority of circumstances.
You forgot that diesel engines are the cleanest co2 engines. They make the most out of a liter diesel.
Less co2 vs more ultra fine particle emission. Obviously you can fuel up with TLG diesel what is very clean.
Hi. Do you have a video on cycloidal propulsion? What are your thoughts on this system? I've seen them used in tugboats and corvettes...
I'm interested to know your thoughts on possibly integrating new technologies like the Exro Technologies Coil Driver which could provide more capability from the inverter of an electric propulsion system. They've not fully integrated into Marine tech yet but experimented with a few partners. I'm hoping you're not bias against electric vehicles 🙏.
I looked at the Exro Technologies Coil Driver. Can't say that I have enough expertise to really discern scientific truth from marketing hype. But no, I'm not against electric vehicles in marine. I don't have a problem with electric technology. But it's my job to see the difference between technology and marketing. A lot of electric marketing tries to hide the fact that electric isn't a perfect solution. It does have limitations. And in some cases, those limits don't justify the application to shipping yet. That being said, I see more applications for electric on ships every year, and I look for them myself. We aren't against electric. The problem is just that electric has to compete against internal combustion, which already had 100 years to refine and improve. That is a large head start to compete against.
Brilliant! Finally someone who knows his stuff. kW = kW regardless of diesel or electric. 👍
But is the way they deliver it not different? I am no engineer but I think you need to push that combustion engine a lot to get to the claimed figure?
I live aboard a 34’ sailboat with electric propulsion, I think your battery weight assumption is wayyyyy too high. 48v 100AH LiFePo4 battery bank maybe weighs 50kg. Definitely not thousands
48V x 100Ah = 4800 Wh or 4.8 kWh
LiFePo4 batteries have around 180 Wh/kg or 5.55 kg/kWh.
4.8 kWh x 5.55 kg/kWh = 26.64 kg
What he is talking about in the video are normal LiPo or Li-Ion batteries for larger boats and ships. Of course they need far more energy.
The battery in an electric car already weighs around a metric ton.
@@razorblade7108 180 Wh/kg is closer to lead acid than lithium iron. Tesla's batteries are at 280 Wh/kg today and improving.
@@skirkwood 180 Wh/kg is for LiFePo4 (or LFP, lithium iron phosphate) batteries, which is what the guy with the sailboat is using. Actually the maximum I could find is a little lower at 176 Wh/kg, I rounded it up. Minimum is around 90 Wh/kg for worse/older LFP batteries. LFP has the highest cycle life and still very good energy density as well as safety (it has no flammable electrolyte), it's often used as replacement for long-lasting lead-acid batteries, however it has poorer low-temperature resistance compared to other lithium and lead-acid batteries. Lead-acid batteries have an energy density of 30-50 Wh/kg by the way.
Other types of lithium batteries have different energy density, some with up to 265 Wh/kg or as low as 50 Wh/kg.
The most common type is lithium nickel manganese cobalt (NMC), which is used in laptops, cars and electronics and has a good mix of power and energy density.
Anther common type is lithium nickel cobalt aluminium oxide. Pure lithium manganese oxide and lithium cobalt oxide batteries are less common, as the mix has better properties overall.
The latest batteries from Tesla (supplied by Panasonic) are lithium nickel cobalt aluminium oxide ones with an energy density of 260 Wh/kg. Your value might be the energy density of the pure materials, but the end product doesn't reach that. The Tesla Powerwall home storage uses lithium nickel manganese cobalt oxide as it has a higher lifespan.
Since lithium iron phosphate batteries need much less rare materials, are safer, have much higher longevity (multiple thousand cycles or 10+ years) and are cheaper, they have reached a pretty high market share despite their lower energy density and will probably replace lithium nickel manganese cobalt oxide batteries over the next years in a lot of applications, except for high performance.
@@skirkwood Lead Acid is 25-35 Wh/kg.
I don't disagree with any of this, but the table at the beginning is not factoring in that any diesel boat will have at least 1000L of fuel (at least as a capacity) so there's that weight to consider. Battery weight is high but if you have a large fuel tank, you could be matching battery vs fuel weight. In addition, all boats have batteries anyway so the difference in battery weight will be the maximum battery weight needed for the engine minus the battery weight already planned.
Well, I'm already ahead of this in my project, a 42' motor sailer. I already am to the point of wanting/requiring a generator for backup, 120/240 power, and hydraulics, a product of my 60+ years at sea commercial fishing and sailing merchant marine, mostly in Alaskan waters. As you can most likely tell, I'm retired, so fast speed is not a need; always watching and anticipating the weather is imperative for my cruising plans.
Glad you made this for "to whom it may concern." My larger issue remains what type of battery system to invest in, I've heard some horror stories using lithium batteries that spontaneously combust. I'm open for comments regarding their safety record. And---Toyota seems to be leading in a next-generation battery using silver as the medium and it sounds very encouraging for not only safety, but very rapid recharging, much better than lithium. Caveat: yes, it remains to be seen, but it's sounding quite likely.
One more thing: looking at the direction things are going politically, the cost and availability of diesel is a major factor in my plans.
There is more crazy shit happening now than I could have imagined just a few years ago. We're heading right into that old Chinese curse "May you live in interesting times." In fact, we're already there.
Lithium ion batteries are temperature sensitive and can self-ignite if they get too hot.
You need LiFePO4 (Lithium-iron-phosphate which is not so sensitive.
You should also know that any lithium battery's BMS (its battery management system) will refuse to recharge the battery at a very low temperature. The reason is that the battery will get damaged. Teslas, and other electric cars has this problem right now.
i disagree with your battery pollution numbers. a ship will be pushing batteries harder than any car, and the cars have to have the whole pack swapped after 5 years due to degradation. but even if you keep it at 5 years, if that ship runs for 20 years, that's 5 battery packs. all of a sudden, the batteries aren't beating diesel. however that also doesn't take into account that extracting, processing and shipping diesel also produces significantly less pollution than the mining of all the substances the batteries are made of.
batteries are not better for the enviroment unless you just hate combustion engines and ignore reality. would the crew/passengers like you to have a battery bank so the generator doesn't have to run at night? sure. would the instant torque that electric motors provide be good for thrusters? long as the water isn't cold, sure.
instead of using things to their strengths, these people demand all or nothing. nuts to them.
You make a good point on the carbon cost for battery production. I intentionally avoided tracing the carbon footprint for engine production and battery production. That can become a very difficult summation since you need to consider the full supply chain and the CO2 cost for transporting components across a global supply network. It just opens more questions than it answers.
I also feel the CO2 cost is not the major issue to use batteries on ships. Weight is the major issue. We simply can't store enough energy at a small enough weight in batteries. They don't even come close to matching current internal combustion. So I still recommend internal combustion on every ship. But I have seen great advantages with the hybrid approach. Use a smaller battery pack combined with a generator or engine. This has the advantage of drastically reducing the time you run the engine, especially with yachts. And for the propulsion, the battery acts as a buffer, allowing you to run the engine at exactly one speed for peak efficiency.
Since when do cars swap battery packs every five years? That's simply a lie. Like there's nothing to unpack there, that's just bottom to top a lie.
Tesla is rated at 1500 full cycles or about 400,000 miles. You do that in 5 years!? You can if you drive a full cycle basically every single day, BUT I call BS on that!
@@zachstine3468 1500 cycles are reached rather quickly if you use it daily
@@razorblade7108 a half cycle does not deplete the battery life the same as a full cycle. driving 1 hour a day is a fraction of a cycle and the battery may go 3,000 or more cycles driving a short amount per day. you should expect 300k miles or more from a tesla battery, which is usually more than 15 years for most drivers and even then, the battery has 80% of the range.
I have a paper proving that Tesla's semi is not possible, at least the original design promised in 2016/17. Now that they are looking at LiPO4 batteries, those numbers look even worse. The bigger the object, the laws of diminishing returns grow exponentially. The true benefits of electric propulsion are for small vehicles and crafts. For example, a tow truck in an airport. It works for short distances and a smaller battery can be recharged in short durations. Similarly, you could have a car with 100-150 miles range instead of 300+ miles to run errands and commuting.
Very much a layman question here. I'm in the process of having a boat built, 29' DE type, inboard, 270hp diesel spec'd currently.
As I understand it a diesel prefers to operate in a given range for maximum efficiency, yet a hulls most efficient performance, (in terms of fuel consumption, is "hull speed." Hullspeed tends to require a far lower power requirement that's lower than where the engine is at optimal performance. Does a hybrid solution address this mismatch?
The weight of the battery bank required for 35hrs of motoring is incredible. (I thought I would check the numbers and I see your energy density is quite low at 1kWh=17.6kg but probably realistic. A 100Ah, 12V Battle Born battery weighs 14kg so has an energy density of 11.7kg at 100% discharge, given you don't want 100% discharge + weight of cables etc, the 17.6kg looks about right, as I said before - incredible)
DMS is forgetting the difference in conversion efficiency. An ICE is 30% eff on a good day. So you cannot equate stored energy in the diesel fuel to the battery and call is apples to apples comparison in this case. Nick's weight comparison is FUBAR!
your calcs are wrong. a 12v battle born battery is a case plus a BMS plus cells. you dont factor in all that weight. 16 lifepo4 300ah cells weigh 100kg. use that in your calc.
you numbers are 140% of actual
I wonder if a CAES system will be better. The vessel has to be build around the compressed-air storage units. There're efficient compressors and motors. They work at about 12 atm pressure.
A:
prop re-gen, in Sail Power applications, makes electric propulsion worth it to me.
( because prop power, in such applications, is an intermittent requirement .....so it's the way it can recharge on a hydrodynamic drag trade off, under sail )
Great Video. I do wonder if you could have included more information on the advantage electric drives can give you for close quarters maneuvering. Many smaller vessels spend a significant amount of time close to shore and docking etc, and the quick responsiveness of electrical motors may be invaluable . I know that many boats already use electrical motors in maneuvering thrusters, but I suspect that their can be other useful possibilities. Would two screw systems be useful?
2:33 So are we not counting emissions from power generation? Just teasing, one thing I would like to add if you have a battery fire then its checkmate, game over, the vessel is lost. Current gen Lithium ion would burn and corrode a hole in the hull in very short time.
Nobody considers pure EV ships as of 2024.
I was thinking about hybrids like Diesel Electric trains which are efficient.
Solar works for me. But I do have a standby generator.
Lol, I love this channel. Thanks for bringing some personality in with all the useful information you present.
What not use a Sears format faraday disk have the primary disk hooked up to a drive motor and the secondary hooked up to the screw or turbine or whatever is being used to move the ship.
I would say the words myth and lies are unnecessarily negative and click bait. For example:It should be pretty clear that „peak power „ is something different than „continuous power „ and the words are pretty self explanatory. Second point about range: We own a sailboat in the Bay Area. With our diesel engine we could motor days on end. Every three month or so we fill up on diesel because our gauge seems unreliable. There have been instances where I went to the gas station and filled up one gallon. For our boat and use you could argue that our diesel system / tank is mismatched to our use. An electric system with a range of 40 miles would be more than enough including safety range. This evaluation is off course personal but I think it would apply to most sail bouts in the San Francisco bay. I crossed the pacific ones and on my trip to the Galapagos was becalmed for a week.There it was great to be able to motor through this zone. But to go slow in a becalmed area could also be an acceptable option to extend electric range. Every oil change I deal with this toxic sludge. Even drops of it can contaminate large amounts of water. That doesn’t fit at all to the sport of sailing to me.
The don't call it "Electric Boat Shipyard" for nothing and I don't know how a nuclear powered vessel will propel a ship or sub using any other method except electric.
True. I remember that some subs used a steam turbine in place of an electric motor. But all the modern boats do use electric generators and electric motor.
echo has been make electric boats for more than 100 years
The very same proponents of electric vessels are "trying" to create full-sized electric aircraft...with predictable results. That pesky Square-cubed law keeps "getting in the way", higher output thrust from electrics only gets you so far...as we will never see electric airliners. That same mathematical law was applied well when lightweight gas-turbine engines "breathed new life" into the struggling helicopter designs.
True, same applies to electric trucks: the Tesla semi still pales in comparison with respect to range, fast refuelling and load capacity to traditional diesel semi-trailer trucks.
@@shaider1982truck range can't be better that driver range. And Tesla already has driver range covered
6t of. Batteries ist stupid. A daysailer with a 40l diesel refuels once a year - and only because diesel can become bad in warm environments. Only uses 0.02l diesel to get out of the harbor.
What it the co2 emission for charging the batteries and after 1000 charging cycles how much co2 is emitted for the recycling
And the biggest problem is that the 17 different quantities of alloys needed for electrical mobility system in general are limited and their extraction need diesel
This co2 debate is anyway a big hoax and scientifically not prooved
There were some turbo-electric ships in WW2. But here you must remember, that's a 100 MW electric motor AND a 100 MW electric generator, plus the 100 MW turbine engine itself (and they had boilers too for high pressure steam!). That's a lotta weight. With battery-electric it's just a motor and battery, no electric generator nor mechanical engine.
But my point is, for all that extra weight, you have to get really big ships to make it be a relatively small fraction. You seem to be focused on small pleasure-craft, and even there the battery-electric design is still quite a lot of weight. I just thought I'd mention some opposite use-case where electric stuff might make sense.
Yup, Drach and Ryan Szmanski discussed those ships along with the problems that came from those, maintenance being one of them. Hence those were not seen in subsequent designs for surface ships.
Also, I think the energy density of coal/bunker fuel is way higher than any battery.
All this besides the fact that you'll dock and use a charging station that's either run by a diesel generator, or it'll be attached to the grid which is mainly coal and gas powered nearly everywhere in the world. 🤣
Coal powered grid power after transmission losses is about as dirty as regular engine. So even if you charge it with coal power it's ok. Any amount of renewable energy that you get will help.
That last part is far from true. I think this is a common misconception primarily amongst americans. The math says very strongly that the thermal efficiency of combustion based power stations are so much greater than a tiny mobile internal combustion engine that you're always ahead of the game using grid power.
Leo uses a hybrid in the Tally Ho
I was gonna mention that!
please be specific. there are vastly different batteries. You need to be specific in your calculations. Your numbers seem meaningless to me if we dont know what u are refeeing to.
Nicely explain
Your numbers are deceptive, And misleading. Kw is linear to hp but you failed to mention torque curve differences. Secondly your like for like comparison fails to mention that on a typical day of boating you are left with a lot of fuel in your tank that’s uneeded. And that you can’t generate fuel while at anchor. Long voyages fuel wins, day trips or weekend trips, Solar all the way
Electric propulsion is much more reliable and requires almost no maintenance.
You have been drinking the cool Aid!
This is absolute bogus.
Amazing 👏 video informative.
Maersk Offshore: czcams.com/video/bbpve4CXXDU/video.html
Quality as always
BS...t. You forgot the weight of the diesel fuel. Its not that much lighter than modern batteries. Lead ballast gets removed to account for added battery weight if need be. I run electric motors and a car. my servicing has been halved. Electric cars out accelerate Ferrari sports cars fella. Have a look at the latest innovations in props. 2024. Have you looked at the price of fuel lately. If you retire on seven figure income, then diesel is a choice. If you are retiring on a motor yacht with less than that, then electric is the only choice for the future, and remember. Mechanics, if you can find one, charge more than plastic surgeons.
Thank you for your films ... Your advices are priceless 🙂
Who do you take me for? For an idiot? You're wrong.
Only an idiot can compare an engine that is incorrectly connected directly to the shaft and a gearbox that is correctly connected.
If you connect the gearbox incorrectly, losses can be more than 50%.
Only an idiot would try to keep going at peak power all the time. That's why it's peak, because it works for a short time.
And most importantly, only an idiot can forget that the efficiency of electric motors is many times higher. Therefore, a hybrid installation will ALWAYS be more efficient than a purely diesel one. Look at hybrid cars. Everything has been calculated there for a long time. Or look at mining dump trucks. Which have a lifting capacity of more than 400 tons. All the leading manufacturers there have been making only hybrid circuits for more than 60 years. For example, there are Belarusian BelAZs. So they are ALL serial hybrids. I don't remember that the USSR had a shortage of oil. Everyone should understand that if you can't refuel a yacht with diesel, it will stop very soon. An electric motor with a Joule of fuel energy will do more work than a diesel engine with the same joule of diesel fuel energy.
Thank you Nick!!!
Wrong. Emotor and engines aren't compareable by just the power number. Emotors have 100% torque at 1rpm. The engine needs to reach redline to pruduce its power rating. You call yourself an engineer? This is a huge difference. If you know what your taking about that is
I look forward to your concise video with a thorough comparison between electric motor and combustion engines.
Torque is not power. Power is force times speed, or torque times RPM in this case (in different units of measurement). Electric motors reach peak power at max RPM, while combustion engines reach it either at max RPM or some point before, depending on how the torque output is at higher RPM.
There are also different types of electric motors and controllers changing their characteristics. One thing that can be said is that they never have full torque on the first rotation (the controller needs to get the motor spinning first) and the torque drops off at higher RPMs, it does not stay constant. Some combinations of motor and controller can keep the torque quite constant up until some RPM until it drops off quickly at higher RPMs, others will drop off smoothly from start to end.
I don't see how high starting torque would benefit a boat honestly. Accelerating the propellers quickly will cause cavitation and therefore increased damage on the propellers, you need to increase their speed gradually anyways.
Usually this is also done automatically by the controller to reduce the starting torque and accelerate more softly, also to reduce stress on mechanical components.
@@razorblade7108 lol. yes mate. i know all that. why would you assume rpm would not change?? high torque gives you the ability to lower rpm and increase prop pitch and diameter. same propulsion for less friction and noise.
@@DatawaveMarineSolutions why?... firstly im not narcissistic enough to spend my precious time trying to get likes on youtube. secondly there are already 1000 videos on the topic. maybe you should look one up. and thirdly i have actually converted many ICE to electric vehicles and know first hand the comparisons. not just a white board and a text book. if you weren't so busy trying to get likes and attention with your time you might be able to do some real engineering. not just talk about it.
@@freelectron2029 Torque is turning against resistance, but in an electric boat or ship the resistance is water viscosity and inertia as you get going. In a car, resistance is the weight of the car. They’re totally different engineering arenas. Ships need power, torque times rotation velocity. Aircraft are like ships; air resistance to turning the prop is negligible until it’s generating thrust from higher velocity air motion. Again power is what matters there.
What a joke maybe a year ago this made sense but now things are so much better and in another year they'll be way better
Nope!