Is diesel-electric or all-electric the future?

[Simon.Sails]

Originally Posted by CarlF

When battery power is available from solar panels or propeller regeneration the electric motor would be used. If battery power was not available, the conventional propulsion diesel would be used.

Presumably, such a boat would not have a genset at all as the solar panels and regeneration would be enough for the hotel loads on board.

The only problem with your plan is that the regeneration systems installed on sailboats to date have not provided very much electricity. I have several friends who tried them but found that in actual cruising they are just about useless. They only make sense when the boat is sailing near hull speed such that there is excess sail power available. At lower wind speeds a large regenerating propeller slows the boat down too much.

If you could create an inexpensive and efficient propeller regeneration system that could rapidly charge a large lithium battery bank that would be very exciting.

I hope to test that premise in the coming months:
- Dragonfly 920 or 1000 trimaran (used)
- Electric outboard ePropulsion Navy 6.0 Evo 6kW / 9.9HP with up to 1kw regen at 10kn according to the manufacturer (untested, new product)
https://www.epropulsion.com/navy/
- Some 600W semi-flexible solar panels
- Minimal weight (relatively small 48v battery, reduced ballast)

I agree that fully electric only makes sense on a boat that sails really well at most wind speeds.

[Na Mara]

Originally Posted by valhalla360

Who told you this?

Go down to the ICW some time. You will find 90%+ motoring along.

.

Totally agree with you here. We have all of us gotten far to used to motoring our sailboats. Thats partly what attracts me to the all electric sail boat, it forces you to actually sail your boat. It's entirely doable, just look at "sailing Uma" for instance.

I grew up on my Dad's boat and he had the attitude that turning on the engine for anything other than getting into or out of the harbour was a sign of failure. It has to be said that we failed quite a lot, but the ethos has stuck with me through the years.

[GordMay]

Originally Posted by Na Mara

https://www.sciencedirect.com/scienc...562?via%3Dihub
This is the actual research article. All the news reports on it are in Swedish.

Perfect - this is EXACTLY what I wished!
I always seek out primary sources ['the study'], and expert analysis/critique, on technical subjects.
News reports are, primarily, useful only as an alert mechanism.

“The greenhouse gas emissions of an electrified vehicle combined with renewable fuels: Life cycle assessment and policy implications” ~ by Öivind Andersson & Pål Börjesson
➥ https://www.sciencedirect.com/scienc...562?via%3Dihub

[valhalla360]

Originally Posted by Na Mara

Totally agree with you here. We have all of us gotten far to used to motoring our sailboats. Thats partly what attracts me to the all electric sail boat, it forces you to actually sail your boat. It's entirely doable, just look at "sailing Uma" for instance.

I grew up on my Dad's boat and he had the attitude that turning on the engine for anything other than getting into or out of the harbour was a sign of failure. It has to be said that we failed quite a lot, but the ethos has stuck with me through the years.

Much simpler and cheaper, only put 2gal of diesel in your fuel tank. That will force you to sail also without all the cost of conversion...and when you stop playing the game, you can fill up and go back to normal use...plus you don't kill resale value.

[jamhass]

https://betamarine.co.uk/he-hybrid-propulsion/

[moseriw]

Electric propulsion is in spite of the climate balance 50% more harmful than any diesel.
The future is hydrogen HHO.

[moseriw]

btw. Tomorrow I will fly to the Planet Mars and I am sure I will find something against the virus and such.

Do not even think about electric propulsion if you do not want to fall back in the stone age of motion including all security risks due to lack of power.

[GordMay]

Originally Posted by moseriw

1. Electric propulsion is in spite of the climate balance 50% more harmful than any diesel.
2. The future is hydrogen HHO.

1. Not according to any of the science/engineering, I've read.
Your sources?
2. Hydrogen is probably PART of the energy future.
HHO, in itself, is not [usually?] an alternative to gasoline, but a additive to boost the efficiency of the gas engine.

[tomsnrg]

Originally Posted by Na Mara

Hi all,

An interesting piece of research came out in Sweden today that I thought I would share. Some researchers at Lund university did some life-cycle analysis on cars with different kinds of engine architectures and they found that plugin hybrid cars have lower lifetime emissions than BEV´s even in a country like Sweden, where electricity is essentially CO2 neutral, and even using standard gasoline. The difference between HVO diesel fuelled plugin hybrids and BEV´s was starkly in favour of the HVO diesel fueled plugin hybrids.

Basically, the embodied emissions in the larger battery packs of modern BEV´s is approaching 10 times those in a plugin hybrid´s battery pack. Most of the time the electric range of BEV's greatly exceeds the daily driving range needed and so most of the time you are lugging around a big heavy battery for no benefit while the plugin hybrids battery has been specifically sized to meet 80% of daily driving needs. Thus the plugin will do most of its miles on electric anyway and even when its using diesel HVO has only 10% of the emissions of normal diesel. All together this makes the plugin the more environmental option over a whole lifecycle even when electricity is nearly CO2 free.

I think this is interesting for sailors and motorboaters as it questions the received wisdom that the future of boating is all electric. Think about the embodied emissions of a battery bank substantial enough to give the modern sailboat about 50 nautical miles of range underpower, that will also allow for all electric cooking, water heating, air-conditioning and heating, instrumentation and so on. That bank is going to be in the 50-60Kwh range (similar to modern BEV banks). At 48 volts that is equivalent to 1250 Ah bank, a 2500 Ah bank at 24 V, or a 5000 Ah bank at 12V. Now imagine a diesel electric hybrid capable of maybe 5 nautical miles of electric propulsion whilst running ship systems but that heats water off the engine/generator when it runs, that has a Wallas diesel electric oven and stove or similar, a diesel space heater, and so on. This sailboat is going to maybe have about 8 Kwh of batteries (equivalent to about 170Ah at 48V, 340Ah at 24V or 680Ah at 12V). Both boats will be set up for hydrogeneration underway and both will probably also have additional charging using panels. The difference is that the diesel electric also has a diesel generator and a much smaller battery bank.

Now wont the same argument hold here as for cars. With a 5 nautical mile e-range the diesel electric boat will mostly get itself into and out of marinas using electricity, and with the regenerative charging it will mostly meet onboard needs underway without running the generator. The exception would be heating operations that simply burn the diesel on board as in this mode diesel is almost 100% efficient. If, in addition, the diesel used is HVO or equivalent, then you have a very clean boat with an embodied energy not significantly higher than that of a normal cruiser. A typical 40 ft might have about 400-600Ah at 12V in terms of battery capacity. Now compare that to the all electric boat with its substantially larger bank of batteries that is trying to do everything with electricity and ask yourself, does the latter really make sense?

What of hydrogen I hear you ask. Well the same is true of a hydrogen electric boat. Heating operations with hydrogen are more efficient if you just burn the hydrogen than if you convert it to electricity and then use the electricity to heat stuff. Similarly, a hydrogen feulcell boat is one where the battery bank will be significantly smaller than a BEV and will thereby have a lower embodied emissions cost.

So the question still holds true. Does the all electric boat really make sense for cruising?

I'm genuinely interested in the answer as I am going to re power and redo the galley in the next year or two and I'm either going all electric or diesel electric. At the moment I edging toward diesel electric, but I'm open to counter arguments.

I found many of these studies wanting, some spectacularly so. Check the initial assumptions made and with a little background you understand the leaning.



All electric means a diesel fumes and diesel odour free boat, not emitting neither particulate nor NOX nor CO2 locally and ideally charged with renewable electric energy. All electric also is much less seasickness, much less maintenance and much better uptime, simpler systems, more space on board. The diesel stench in older sailboats, impregnated in the structure, to me is nearly painful on otherwise beautiful vessels.

[roland stockham]

The problem we have as a society in getting to a low carbon future is not developing effective alternatives to current carbon tech but changing current attitudes to fuel use. This is really evident when you look at cars. What are the first things car sales people highlight when selling cars? Power, top speed and acceleration. Getting a car to do twice the legal speed limit and get from 0-60 in a few seconds means it has to have a huge engine. I run a jeep because we have lots of gravel roads and very snowy winters that need good 4x4. The jeep has an engine that develops more than 300hp but I have never used more than about 75hp in real life so I could easily reduce the engine size by half and it would still do everything I need. Another example I recently looked at was electric cars with range extenders. They give an electric range of about 100miles which will cover 90% of what I do. If you go further than that a small gas engine kicks in to recharge the battery. Only needs about 30hp to ensure you never run out of battery so why are we building hybrids with 200+ hp engines? The point is that if we continue to expect to be able to use unlimited amounts of power to make things bigger and faster we will never solve the problem. We could actually stop the acceleration of global warming now with current tech if we simply change our attitude to focus on reducing waste,lowering consumption and redirected the economy to produce what we need instead of focusing on everyone consuming more and more in the interests of business making more profit and valued people for what they do not what they own.

[Augi]

Originally Posted by Na Mara

Hi all,

An interesting piece of research came out in Sweden today that I thought I would share. Some researchers at Lund university did some life-cycle analysis on cars with different kinds of engine architectures and they found that plugin hybrid cars have lower lifetime emissions than BEV´s even in a country like Sweden, where electricity is essentially CO2 neutral, and even using standard gasoline. The difference between HVO diesel fuelled plugin hybrids and BEV´s was starkly in favour of the HVO diesel fueled plugin hybrids.

Basically, the embodied emissions in the larger battery packs of modern BEV´s is approaching 10 times those in a plugin hybrid´s battery pack. Most of the time the electric range of BEV's greatly exceeds the daily driving range needed and so most of the time you are lugging around a big heavy battery for no benefit while the plugin hybrids battery has been specifically sized to meet 80% of daily driving needs. Thus the plugin will do most of its miles on electric anyway and even when its using diesel HVO has only 10% of the emissions of normal diesel. All together this makes the plugin the more environmental option over a whole lifecycle even when electricity is nearly CO2 free.

I think this is interesting for sailors and motorboaters as it questions the received wisdom that the future of boating is all electric. Think about the embodied emissions of a battery bank substantial enough to give the modern sailboat about 50 nautical miles of range underpower, that will also allow for all electric cooking, water heating, air-conditioning and heating, instrumentation and so on. That bank is going to be in the 50-60Kwh range (similar to modern BEV banks). At 48 volts that is equivalent to 1250 Ah bank, a 2500 Ah bank at 24 V, or a 5000 Ah bank at 12V. Now imagine a diesel electric hybrid capable of maybe 5 nautical miles of electric propulsion whilst running ship systems but that heats water off the engine/generator when it runs, that has a Wallas diesel electric oven and stove or similar, a diesel space heater, and so on. This sailboat is going to maybe have about 8 Kwh of batteries (equivalent to about 170Ah at 48V, 340Ah at 24V or 680Ah at 12V). Both boats will be set up for hydrogeneration underway and both will probably also have additional charging using panels. The difference is that the diesel electric also has a diesel generator and a much smaller battery bank.

Now wont the same argument hold here as for cars. With a 5 nautical mile e-range the diesel electric boat will mostly get itself into and out of marinas using electricity, and with the regenerative charging it will mostly meet onboard needs underway without running the generator. The exception would be heating operations that simply burn the diesel on board as in this mode diesel is almost 100% efficient. If, in addition, the diesel used is HVO or equivalent, then you have a very clean boat with an embodied energy not significantly higher than that of a normal cruiser. A typical 40 ft might have about 400-600Ah at 12V in terms of battery capacity. Now compare that to the all electric boat with its substantially larger bank of batteries that is trying to do everything with electricity and ask yourself, does the latter really make sense?

What of hydrogen I hear you ask. Well the same is true of a hydrogen electric boat. Heating operations with hydrogen are more efficient if you just burn the hydrogen than if you convert it to electricity and then use the electricity to heat stuff. Similarly, a hydrogen feulcell boat is one where the battery bank will be significantly smaller than a BEV and will thereby have a lower embodied emissions cost.

So the question still holds true. Does the all electric boat really make sense for cruising?

I'm genuinely interested in the answer as I am going to re power and redo the galley in the next year or two and I'm either going all electric or diesel electric. At the moment I edging toward diesel electric, but I'm open to counter arguments.

I think for pleasure yachts that need a lot of range the near future is a diesel / electric parallel hybrid solution. With a parallel hybrid you can have the same diesel capability, range etc and use electric motor for propulsion until until the batteries run down. The diesel engine when providing propulsion can turn the electric motor so it acts as a generator to charge the batteries.

I am not sure why the above solution has not caught on more? There are parallel diesel hybrid solutions being manufactured and used. Could be cost and / or all the kinks may not have been worked out sufficiently.

An idea for Cats is put a diesel engine in one hull and an electric motor in the other as a different kind of hybrid. Plus use something like the Integrel Solutions' generator / alternator on steroids(see link) connected to the diesel engine to charge the batteries rapidly without having to have a separate, independent generator. https://integrelsolutions.com

[WhiteHill]

There's a recent informative discussion on this topic, especially pertaining to electric regeneration and which includes some useful numbers, at the AAC site:

https://www.morganscloud.com/2021/03...sing-sailboat/

[Adelie]

Originally Posted by valhalla360

Who told you this?



Go down to the ICW some time. You will find 90%+ motoring along.



If you are talking about folks who day sail out of a single marina, it's largely irrelevant. They might burn 5-10gal of diesel per year. You aren't eliminating any significant amount of fuel burnt.



.....

The ICW is a special case, like the canals of Europe. Extrapolating from observations there to general behavior around the world would lead to false conclusions.

If 95% of sailboats are only daysailing out of marinas then that 5-10gal/yr is a significant fraction of fuel used by all sailboats and switching to electric drive would have significant effects.

[Na Mara]

Originally Posted by valhalla360

Much simpler and cheaper, only put 2gal of diesel in your fuel tank. That will force you to sail also without all the cost of conversion...and when you stop playing the game, you can fill up and go back to normal use...plus you don't kill resale value.

Ha. Yes I could certainly do this, or I could electrify the ignition key so i get shocked every time I reach for it. You are going to have to really want to put the engine on then.

In all seriousness though I think that something like this attitude is probably the way forward. View the engine as the auxiliary it was meant to be and run it as little as possible. Set the boat up so she sails really well in all conditions and the temptation to start up the engine will be reduced.

If I can keep usage down to 5 nm a trip then that is only 3l of diesel a trip, which is about 8 kg of CO2. Living aboard I might do 50 trips a year, which would be a total of 400kg a year, which is just 50kg more than the average person breaths out in a year. Put into perspective the annual per capita emissions in the US was 16.5 tons in 2017 while it was 4.5tons in sweden. Considering how many emissions one avoids living aboard (simpler lifestyle, lower power consumption, no car, etc) these 400kg seem entirely justifiable to me.

Further, a central estimate of the embodied emissions of 1kWh of lithium battery is around 100kg excluding end of life disposal so let's say 200kg per kWh all in to be realistic. A 26 kw battery like that for the all electric ocean volt system I raised earlier would then represent around 5 tons of emissions. I could live aboard being frugal with my engine for 11 or more years before I came up to those level of emissions, at which time the battery in the all electric will need replacing.

https://www.transportenvironment.org..._batteries.pdf

Yeap the more I think about this the more I think just keeping the engine I have got and using it as little as possible is the way to go (saves on engine maintenance too). If I find myself cheating too much then I will keep your suggestion in mind for how to keep me on the straight and narrow.

[Augi]

Originally Posted by jamhass

https://betamarine.co.uk/he-hybrid-propulsion/

What I understand is the company at the link mainly sells hybrid solutions to canal boats. Obviously, canal boats can carry a huge amount of weight of batteries that can take up a lot of space versus a sailing yacht. No need to necessarily pay up for lithium batteries.

I think the reason why parallel hybrid diesel electric set ups have not caught on is in sailing yachts is the electric aspect does not provide very much utility versus the expense / extra complication.

A hybrid parallel solution like produced at the above company is for a direct drive transmission. So many pleasure sailing yachts these days have sail drive transmissions. The move to more sail drive transmissions seems to be motivated by that they cost less and are easier to install

I believe the above company with Yanmar tried to develop a similar parallel hybrid system using a sail drive transmission and it did not go well enough to be worth the trouble/cost to develop.