The future of diesel inboards in an all electric future

[robshookphoto]

The diesels most people use in sailboats are already illegal on the road because non-common rail engines pollute horribly. People need to chill out. These bans aren't going to hit sailboats until most people have already completely switched over. The stop gap will be dirt cheap electric propulsion with a common rail generator.

I'm already an ocean cruiser with solar-electric only. Generator-electric replaces diesel already, and no laws are going to force you to rip a working diesel out of your boat.

 

[TWOBOATER]

We're a corner case. Usage is so small that an exception is warranted, and that's where efforts should be focussed, for now. If and when technology improves to meet requirements, inboard diesels will fall out of use naturally.
For most sailors an auxiliary engine is a necessary evil and would be replaced with something quieter and cleaner at the first practical opportunity. As soon as a safe, reliable and capable alternative is available, the diesel's days will be numbered... arguably, they are already, we just don't know the number yet.

Regarding small usage, yes sail boats do use little fuel comparatively, but 50 plus foot recreational power boats use lots of fuel, especially when you consider it's just for recreation. I work for a yard and sea-trialed a 53 foot power boat with twin CAT 1100 HP engines. At full throttle this house-sized boat goes 35 knots! while burning 55 GPH per engine. A long weekend away on this boat would burn about enough fuel to heat a 3 bedroom home for a year! That's not small potatoes in the scheme of things. How is government going to go after the toys of these super rich people who are the power brokers of the day?

 

[Waiex191]

Generation is in DC and must be converted to AC for transmission, depending upon the method of conversion the efficiency can be as high as 90% which would be expected at a power plant.

I would expect that no generation is in DC. What I would expect is the generators would be either induction machines or permanent magnet (PM) machines. This is actually true for our modern electric "DC" motors as well. DC is just a stopover to feed an inverter so our AC motors can look like the DC machines of olde, and give us variable speed plus torque control.

 

[a8b]

its correct what u say...development is not there yet..for many boaters...my guess is hydrogen engines..with hydrogen produced from renewalde energy....

Hydrogen was always a scam

The diesels most people use in sailboats are already illegal on the road because non-common rail engines pollute horribly.

But way less than petrol without a catalytic, right?
How many of those outboards do you imagine have a catalytic?

I would expect that no generation is in DC. What I would expect is the generators would be either induction machines or permanent magnet (PM) machines. This is actually true for our modern electric "DC" motors as well. DC is just a stopover to feed an inverter so our AC motors can look like the DC machines of olde, and give us variable speed plus torque control.

And none if this generation is induction, right? It would have to be a very old generator to be induction.

 

[rcpmac]

So I was reading an article today about the upcoming bans on combustion engines in new cars and it got me thinking about inboards.
The EU are saying all new sales must be electric from 2035, the UK before that at 2030.

Now this doesn't apply to boats yet (as far as I'm aware), but it can't be too long before legislators turn their eyes towards leisure boating and the emissions we produce, naturally we're in a better position than power boaters, but I'm sure all of us have plugged away for hours under engine to make a tidal gate / make progress when there's no wind, or just to get back in time for work.

The 45 litre tank on my small 27'er will keep me going for at least 40 hours steaming, at a weight of just 45kg.
As far as I'm aware, even the best battery techs aren't close to that yet, and they come with some pretty big safety concerns. LifeP04 I'd probably need close to 500kg of batteries to get the same performance.
For lake sailors and day sailors it's probably an easy switch, for coastal sailors less so.

I'm wondering what people think is going to be the future of the inboard? Better as yet not released battery tech? Hydrogen? Biofuels?

My 12 ton Ingrid diesel auxiliary is fueled with biodiesel. Next problem?

 

[floater]

Meanwhile, my startup (Terraform Industries) is making machines to extract excess CO2 from the atmosphere and creating fossil-free natural gas. When we are successful (!) we will replace the feedstock of the petrochemical industry with non-fossil gas, making the entire petrochemical industry planet savers, rather than planet killers.

great to hear this project still proceeding.

because with electric, we motor sail, we don't just motor around like a powerboat.

cemented in my memory is sitting - wearily - at the fuel dock in Morro Bay after a monotonous slog up the coast from Conception. We were on a traditional full keeler, and with a big loud engine. but then a fantastic racing yacht appeared - single handed - with a bright and cheery skipper aboard. he had also motored up from Conception in the wee hours - but differently - his main was at full hoist and he described the journey as wonderful. lol. I still recall him taking off with a big smile on his face. as he sheeted that big main in. (Absolute 88 - if anybody remembers it. a Wylie I think).

 

[MiddayGun]

The diesels most people use in sailboats are already illegal on the road because non-common rail engines pollute horribly. People need to chill out. These bans aren't going to hit sailboats until most people have already completely switched over. The stop gap will be dirt cheap electric propulsion with a common rail generator.

I believe Yanmar now do common rail as low as something like 45hp?
But the pollution is not the CO2, its the NOx emissions, but given that they're out at sea for the most part, not creating a haze of pollution within cities, then its less of a problem.

My concern is less that they come for boaters specifically, more that we get caught up in some sweeping catch all legislation. Or that diesel becomes so expensive you'd rather miss work than motor!

 

[Tedd]

At least in the U.S. and Canada, leaded fuel is still allowed for aircraft. By analogy, it wouldn't surprise me if nobody takes much notice of the existing fleet of sailboats for quite a long time, with respect to CO2 emissions. But I don't know if that necessarily applies in other countries.

Regarding range and battery mass, it would very much surprise me if new sailboat designs don't start treating batteries as ballast. Perhaps some already do. For retrofitting, battery mass is a big deal, but for new designs it's much more a question of battery cost than battery mass. And battery volume too, I suppose, although that would be less of a problem. It's probably not practical yet to put batteries in the keel, but certainly where the non-keel ballast would go.

 

[illan_voyager]

Lots of partial info and blatant mis-information posted, as typical for this type of subject.

-An electric motor & associated storage/system is say on average 80% efficient, a modern small diesel is say 25% efficient. This makes up for transmission losses on the grid and other inefficiencies ex; converting ac-dc..and back, if needed. Even if the grid power is coming from fossil fuels (large power generation ex natural gas can be 50-65% efficiency with some waste/heat recovery) - still makes more sense to go electric as far as end user cost of operation goes, by a significant margin. So the only real consideration is range vs weight (and cost). At some size weight is less of an issue, and for many uses but not all, for a cruising boat, diesel electric already makes the most sense.
-Biodiesel and straight vegetable oil as fuel are already established alternatives (with no downsides) and will come into play more as the price of oil goes up- the only reason they haven't received more attention is the general political problem with all diesels, NOx, a consideration on-road & for cruise ships in harbor but not necessarily as important in most general marine applications.
-Ethanol (from corn - subsidies lining farmers pockets) and hydrogen fuel cells (producing hydrogen always consumes more energy than using the energy to charge batteries- so unless there is an overabundance of renewable energy- batteries will always be a better storage option)... are both a scam and have always been. Oil/Auto companies selling it as a "green" future pipe dream & receiving excessive government funding.
-The propane outboards are certainly still being made, tohatsu sells some. There is no downside here other than size of tank required for longer runtimes. I'm not sure if Lehr went out of business or just restructuring, I still have seen some in stores.
-Yes you can easily charge batteries by spinning the prop while sailing on many if not most decent electric inboard conversions & installations. I'm not sure if any commercially produced electric outboards have this option.

 

[seandepagnier]

Now this doesn't apply to boats yet (as far as I'm aware), but it can't be too long before legislators turn their eyes towards leisure boating and the emissions we produce, naturally we're in a better position than power boaters, but I'm sure all of us have plugged away for hours under engine to make a tidal gate / make progress when there's no wind, or just to get back in time for work.

Not "all of us". I never used any kind of combustion engine.

We're a corner case. Usage is so small that an exception is warranted, and that's where efforts should be focussed, for now. If and when technology improves to meet requirements, inboard diesels will fall out of use naturally.
For most sailors an auxiliary engine is a necessary evil and would be replaced with something quieter and cleaner at the first practical opportunity. As soon as a safe, reliable and capable alternative is available, the diesel's days will be numbered... arguably, they are already, we just don't know the number yet.

An exception is warranted to ban combusion engines on boats before cars.

They pollute more (no catalytic converters, oil in water) but most of all they are not needed, since there are sails, and recreational boats are not even essential.

Most aspects of sail-boating will always need compact, reliable power, powered by an efficiently packaged fuel source for safety reasons. Some missions (example: the doldrums on the way to Hawai'i) are best done with ICE/diesel as you will never beat the energy efficiency of a gallon of diesel. Other shorter duration missions can be accomplished with electric and battery technology available now.

Not only is this incorrect, it is insulting your own competence. I have sailed in the doldrums many times in all different oceans. It is wrong motor here. Modern boats typically only get stuck a few hours anyway because we can sail faster than the wind, upwind.

Unless your boat sails faster than the wind most of the time: it is in danger to storms. The displacement speed is too slow engine or sail, so claiming an engine makes it safer is wrong priority along with a long list of other things that diesel junkies prioritize in the incorrect order. In fact engine-free sailors are much less likely to be rescued.

As pointed out above, when the capability/efficiency/cost of alternate solutions become available, diesel will fall by the way side (like steam and inboard petrol engines). When will that be? Not soon. Still waiting for my flying car.

Then we get the ridiculousness of carbon offset credits. Here, a sailboat, by the nature of its primary propulsion (wind), is nothing more than a carbon offset generation machine. If you cooked the formula correctly, a small sailboat could offset the energy use of a 1000' container ship without planting a single tree. It's all how you game the system.

Sailboats do not offset carbon. If you offset carbon it means you have to bury CO2 underground in a form it can stay for thousands of years. Most carbon offset schemes (eg planting trees) are not legitimate as they do not compensate for the fossil carbon released.

A gallon of diesel is one of the most efficient ways to store energy, and you can carry only the amount you need.

How do you measure efficiency? Convert the energy of sail power with a hydro turbine into gasoline and your efficiency is below 0.1% and requires special catalysts. gasoline is not an efficient way to store energy, it may be an efficient carrier.

It might sound silly, but provided we don't blow ourselves back to the 19th century, i expect most rear earth material mining and processing to be done on the moon in the next 50-75 years. Most heavy industry in general.

I've always been taught to fear propane on a boat. I suppose with proper bilge ventilation ect though, might not be any worse than gasoline. Though im not sure which one is heavier.

I use hydrogen. It can be produced from excess PV and burned for cooking. It is safe by comparison to propane.

 

[Expat Canuck]

Lots of partial info and blatant mis-information posted, as typical for this type of subject.

-An electric motor & associated storage/system is say on average 80% efficient, a modern small diesel is say 25% efficient.

Your second sentence proves the truth of the first.
Diesel-mechanical installations (direct connection from engine to prop via gearbox) are in the 93 to 95% efficiency range.
Diesel-electrical installations (diesel generator to electric motor) are closer to 80% efficient.

 

[illan_voyager]

Two very different things, you're considering the efficiency of the drivetrain, while I was talking about overall efficiency converting the available energy in stored fuel to forward motion.

Sure a diesel mechanical installation could/would be (upto) 93-ish% efficient when you consider only the drivetrain resistance/losses , but I was referring to overall efficiency of the fuel. ~20% of the available stored energy in diesel fuel is converted to usable forward motion, while 80% of the available energy is lost as heat- when burning diesel in normal efficient rpm range in any small combustion engine. With electric it's ~85-95% of the available energy stored in the battery is converted to forward motion (since you were going with the best case #'s for mechanical-diesel). My rough 80% efficiency estimate posted above (overall for electric only) was including the charging inefficiency of lithium say 5%.

An electric only install is also going to have very little "drivetrain" losses, certainly in efficient examples in the same 90%+ range as the diesel-mechanical above. Electric installations don't often/typically need transmissions, which are just adding extra drivetrain resistance, by the way.

Diesel electric may of course not be right for all, and there are significant inefficiencies as you point out BUT there are of course other benefits as you're not necessarily running the diesel all the time- think of it like a plug-in hybrid car.

Everyone will have to choose for themselves when they take a look at the whole picture: -big enough boat to carry a large li-ion battery? -Good sailing boat that will have the sails up in most conditions -ability to put a significant trickle charge into the pack via solar? -Will it be parked in a slip where you can charge regularly?

I think for a lot of use cases it makes sense to take a serious look at electric, and then diesel-electric if "range anxiety" is a concern.

No rose colored glasses as I love my diesel engines by the way and don't think I would personally retrofit even a blown diesel (because I can rebuild my own diesel-even a worst case scenario volvo- for a lot less than a electric conversion), but it's worth an honest look on a case by case basis. A lot of the day sail catamarans seem to be doing pretty well with diesel-electric in my part of the world. I've sailed and also helped with quite a few electric conversions & installs in cruising boats. For example if I were comparing electric to a new Yanmar install, I would prefer to piece together my own quality electric-only setup, personally. I would then be able to add a reasonably small generator later, if needed.

 

[illan_voyager]

I use hydrogen. It can be produced from excess PV and burned for cooking. It is safe by comparison to propane.

Stored hydrogen is not safer than propane. Hydrogen is a small molecule and tanks/lines required are MUCH more expensive and the seals/o-rings much more high maintenance than propane. Either can be highly explosive and "dangerous" with leaks or other issues. Homebrew hydrogen systems could be quite dangerous. Either can be safe with proper maintenance and systems. Hydrogen as "green" - (either burning it or putting it through a fuel cell) is a scam. You are better off using the excess of PV to power an electric cooking element (or charge batteries to be used later) than burning hydrogen. Think about it- to produce hydrogen you're talking about using electricity to split water- there is no free energy.

Like gas/diesel, sure, hydrogen can be a lightweight way to store fuel. That's why you might see the occasional hydrogen fuel cell on a high budget boat project. They're not breaking down H2O using solar by the way, they're filling up their tank on shore. Greenwashing is usually a bonus in these cases. Not because it makes ANY sense. Look at the full story of the Toyota Mirai in California, a Subsidized BS government pet project of the oil companies, millions/billions public eco $ spent (government & automakers), all to try to convince the general public all is good and theyre slowly working towards (but not there yet) perfect "green" future. To keep up the illusion that people can keep up just doing the same without changing their own lives - feel good advertizing, that has worked remarkably well

 

[a8b]

Your second sentence proves the truth of the first.
Diesel-mechanical installations (direct connection from engine to prop via gearbox) are in the 93 to 95% efficiency range.
Diesel-electrical installations (diesel generator to electric motor) are closer to 80% efficient.

This is all wrong
I think super modern low speed marine diesels are ~54% iirc efficient.

It is easy for a diesel electric to beat a direct drive diesel, as electric drives can better fit the varied energy demands and the diesel can produce electricity at a fix, max efficient point.

An easy example of this is diesel electric locomotives.
The transmission needed to beat the capabilities of the electric drive motors are impractical.

 

[floater]

It is easy for a diesel electric to beat a direct drive diesel

quien es mas macho?

 

[illan_voyager]

This is all wrong

Canuck was thinking only about drivetrain losses for some reason, you an I are talking about the overall efficiency of converting the available btu's in the stored "fuel" to usable "work"

I think super modern low speed marine diesels are ~54% iirc efficient.

I think 54% would be an extreme example, possibly/likely from a much larger setup, but yes commercially available diesel gensets in the smaller size running at their efficient rpm range can be upwards of 40-50% efficient. (again that beats the 20-25% of a typical modern mechanical diesel install).

Did someone mention big low rpm 1 cylinder's like Lister yet?

 

[a8b]

Canuck was thinking only about drivetrain losses for some reason, you an I are talking about the overall efficiency of converting the available btu's in the stored "fuel" to usable "work"

I think 54% would be an extreme example, possibly/likely from a much larger setup, but yes commercially available diesel gensets in the smaller size running at their efficient rpm range can be upwards of 40-50% efficient. (again that beats the 20-25% of a typical modern mechanical diesel install).

Did someone mention big low rpm 1 cylinder's like Lister yet?

Odd to focus on how efficient gears are, and ignore that you need to change rpm, which takes double digit percents off the top.

Thats how they get 54%, iirc. 1 rpm.

Can we all agree that hydrogen is a lie?
Burning hydrogen is like powering your outboard with bottels of scotch.

The only resonable way to use hydrogen is as a battery(fuel cell) which is bullshit all the way down, in that it is bad at it's job and expensive heavy, and complicated.
It's the ethanol of gas fuels.

 

[slap]

Stored hydrogen is not safer than propane.

Propane is heavier than air so can "pool" in the boat if it leaks. Hydrogen is lighter than air so it will try to escape "up" and is far less likely to create a dangerous "pool".

 

[a8b]

Propane is heavier than air so can "pool" in the boat if it leaks. Hydrogen is lighter than air so it will try to escape "up" and is far less likely to create a dangerous "pool".

Because no roofs are curved upside down pools that would be perfect to pool hydrogen.

 

[El Borracho]

Until the hydrogen economy arrives, if ever, an elegant solution for long distance sailors could be a very small, quiet, petroleum-fueled engine. Something elegant. 3 to 10 hp could be plenty with a battery-electric drive. Something is amiss with the marine diesel generator offerings as they tend to be complicated, noisy, and expensive. Think a “Honda” generator but without the volatile gasoline.