Triskel power generation system on Distant Shores III

[tanglewood]

Originally Posted by john61ct

Well not too many sailboats in the 20-40' range have that big an engine.

This system seems to be sized OK for their normal HP range and with a LFP bank.

Note just like solar, excess power produced "for free" while motoring could be charging holding plates, making or heating water, etc

And once accepted in the marketplace, bigger and smaller alts can be added to the line.

Nor would a 400hp engine be found in a 30-40' displacement trawler. 80 to maybe 150 hp would be more typical. Lots of Lehman 125hp, give or take. But big enough that 15hp for a really big alternator won't move the dial in any significant way while underway, and won't create any meaningful load at idle, or slightly above.


It keeps coming back to a fit where the alternator load is around 20% or more of the main engine's capacity - in other words large enough to overwhelm the main under circumstances that occur on a normal basis.


And speaking of alternators that load the engine more than 20%, what sort of limits do the typical sail boat engine manufacturers allow for pulley driven loads? Yanmar seems to be popular. I've only looked at Cummins, Deere, Lugger, etc. who are generally bigger, continuous duty engines. 10% sticks in my head, though it varies from engine to engine.

[john61ct]

Well I've looked at alts turned out to require 30HP, and many boats just have an Atomic 4 with 10.

So obviously this current prototyping / testing stage, the size they've chosen will work well with a certain set of engines, not all.

Just dropping into an existing setup with minimal mods restricts the choices even further.

And pulleys are just one drivetrain option, for those eliminating the need for a dedicated genset, may well be worth choosing / adapting the engine to suit the alt's needs if you can.

[Dockhead]

Originally Posted by tanglewood

Nor would a 400hp engine be found in a 30-40' displacement trawler. 80 to maybe 150 hp would be more typical. Lots of Lehman 125hp, give or take. But big enough that 15hp for a really big alternator won't move the dial in any significant way while underway, and won't create any meaningful load at idle, or slightly above..

Why do you think a 15hp alternator wouldn't create a meaningful load at idle, for a 125 hp engine?


Looks to me like the Lehman 125 produces about 30hp at idle. Even a much smaller alternator than that, should be plenty to keep that engine happy.


While underway -- 15 hp power taken off might or might be ok -- depends on the propeller curve. Certainly, that much power "moves the dial"-- that's 12% of maximum power and maybe 20% of power available at mid RPMs. Might well be too much depending on the prop.

[a64pilot]

What is it your trying to accomplish?
Your not going to save any fuel, unless you motor nearly every day, then you will save some. If you seldom motor, then it’s going to cost more fuel, cause your big motor making the same power is less efficient than a smaller motor, so any fuel you save by making power when motoring is going to be more than offset when you run the big motor as a generator.

As far as fuel burn, my little Nexgen which will charge at 185 amps into 14.3 VDC burns 1 gt an hour, so four hours for each gallon.

I’ve not watched the video, but this sure seems like something a motor yacht would gain the most from, except of course at anchor you have to run the big motor to make electricity, and that is I think the fallacy, of your always moving, never at anchor, then a system like this is logical, but drop anchor to stay somewhere for a few weeks before you move onto the next place to stay a few weeks, and its usefulness breaks down, cause your putting a whole lot of hours on your most expensive engine.
I don’t really know as a I have not repowered, but based off of number I see here, I can replace my little Nexgen four or more times for what it will cost to replace my propulsion motor, so the money savings breaks down too.
Then apparently you need multiple battery banks? And a few more black boxes? And a place to mount God’s own alternator in your engine?
I can’t even mount a large frame alt on mine, not without major surgery to the engine enclosure making a bump or something that would protrude into the Salon.
So I don’t see any space savings either, not over a small generator?

So to summarize.

1. No appreciable fuel savings, in my opinion.
2. No real space savings, over a small generator
3. What is it going to cost?
4. How major are the modifications that will have to be made to the engine and engine surround?
5. You have no electrical redundancy, lose that one engine and you lose all electrical generation. Currently with a generator, you have two sources of electrical power.
6. Significant increase in number of operating hours on the biggest, most expensive engine. To determine how much, just add your generator hours onto your main engine, unless you run your generator when your motoring, and that is I think very uncommon for a sailboat.
7. Weight savings? A small Diesel Genset complete is like 200 lbs, how much weight do you think you will save?

Now maybe for those that are almost always underway and don’t spend much if any time at anchor, and have money to spend, then this may be what they want.

[OceanPlanet]

Originally Posted by a64pilot

What is it your trying to accomplish?
Your not going to save any fuel, unless you motor nearly every day, then you will save some. If you seldom motor, then it’s going to cost more fuel, cause your big motor making the same power is less efficient than a smaller motor, so any fuel you save by making power when motoring is going to be more than offset when you run the big motor as a generator.

As far as fuel burn, my little Nexgen which will charge at 185 amps into 14.3 VDC burns 1 gt an hour, so four hours for each gallon.

I’ve not watched the video, but this sure seems like something a motor yacht would gain the most from, except of course at anchor you have to run the big motor to make electricity, and that is I think the fallacy, of your always moving, never at anchor, then a system like this is logical, but drop anchor to stay somewhere for a few weeks before you move onto the next place to stay a few weeks, and its usefulness breaks down, cause your putting a whole lot of hours on your most expensive engine.
I don’t really know as a I have not repowered, but based off of number I see here, I can replace my little Nexgen four or more times for what it will cost to replace my propulsion motor, so the money savings breaks down too.
Then apparently you need multiple battery banks? And a few more black boxes? And a place to mount God’s own alternator in your engine?
I can’t even mount a large frame alt on mine, not without major surgery to the engine enclosure making a bump or something that would protrude into the Salon.
So I don’t see any space savings either, not over a small generator?

So to summarize.

1. No appreciable fuel savings, in my opinion.
2. No real space savings, over a small generator
3. What is it going to cost?
4. How major are the modifications that will have to be made to the engine and engine surround?
5. You have no electrical redundancy, lose that one engine and you lose all electrical generation. Currently with a generator, you have two sources of electrical power.
6. Significant increase in number of operating hours on the biggest, most expensive engine. To determine how much, just add your generator hours onto your main engine, unless you run your generator underway, and that is I think very uncommon for a sailboat.
7. Weight savings? A small Diesel Genset complete is like 200 lbs, how much weight do you think you will save?

Now maybe for those that are almost always underway and don’t spend much if any time at anchor, and have money to spend, then this may be what they want.

You should watch Nigel's video.

However for boats with low loads, the system would indeed be overkill. The system makes sense for those with high loads that typically would have a generator running to keep up. In tandem with Li batteries the great reduction in charging times is a major change in on-board lifestyle.

185A @ 14V (approx 2.6kW) is not nearly enough for the boats that would use this system. 8+kW is another story, and allows moving some real energy into the batteries allowing shutting off the engine(s) for most of the time even on yachts with high AC loads.

[a64pilot]

Interesting to see 185 amps defined as low loads.
From the average cruiser, I think I’m a power hog, using almost 300 AH in a 24 hour period, which it seems is at least double the average.

Back to my original belief that this sounds like a system the average power boat that runs their generator while underway would benefit from, or maybe someone who wants to cook on an electric stove while running the AC?

Not trying to sarcastic, but my little 3.5 KW generator which is where the 185 amps of charging comes from output is 30 amps, which is the max power a lot of cruisers can get from their shorepower plug.

Good lord what are you people doing that requires significantly more power than that?

[john61ct]

Sitting on the hook, with big enough LFP, then the higher the **charging** amps the shorter the runtime. The lower your daily usage, even more so.

And / or charging holding plates, making high GPH water, maybe hot water, doing the cooking and laundry etc.

Say 6 hours total in 2-3 sessions a week, properly managing the engine to avoid the dreaded low-loading problems.

Without a genset, not just the weight but the cost.

Sounds good to me.

The extra wear and tear on the propulsion motor, really are we talking overhaul going to be needed at 8 years instead of 12 or something?

[OceanPlanet]

Originally Posted by a64pilot

Interesting to see 185 amps defined as low loads.
From the average cruiser, I think I’m a power hog, using almost 300 AH in a 24 hour period, which it seems is at least double the average.

Back to my original belief that this sounds like a system the average power boat that runs their generator while underway would benefit from, or maybe someone who wants to cook on an electric stove while running the AC?

Not trying to sarcastic, but my little 3.5 KW generator which is where the 185 amps of charging comes from output is 30 amps, which is the max power a lot of cruisers can get from their shorepower plug.

Good lord what are you people doing that requires significantly more power than that?

Good question! Some of the yachts we do systems for pull more power than my house. Obviously AirCon, but also things like dive compressors, large AC-powered reefers/freezers, etc. etc.

Some of the larger powerboats with Li batteries (Coastal Craft for instance, our batteries are standard on them) use the power assist feature of the Victron Quattros to pull from the batteries when high loads can blow the shore power breakers. So the loads can be quite high indeed.

[john61ct]

Yes, I was focusing on my low budget small-is-beautiful case, where such a unit would be maybe the most significant energy source

But I can see these fitting right in even (especially? ) when they're just one piece of the overall puzzle.

When a few more (dozen) boat bucks are not even noticed.

[a64pilot]

Originally Posted by john61ct

Yes, I was focusing on my low budget small-is-beautiful case, where such a unit would be maybe the most significant energy source

But I can see these fitting right in even (especially? ) when they're just one piece of the overall puzzle.

When a few more (dozen) boat bucks are not even noticed.

No, this is for the big boy’s. It’s an economy of scale kind of thing where it makes more sense, the more power you make from it. Yes it’s possible at much lower power levels, but it’s not a make half the power for half the cost kind of thing. The initial expense isn’t insignificant.
However I guess you can make it like a Watermaker argument, my Watermaker will never pay for itself in offsetting the water I won’t need to buy, but the convenience to me is worth it.
I’d just swag that it’s more than a $20,000 US cost for the entire system, and that may not even be close, as I said I have not watched the video, so that is a WAG, not a SWAG, it’s likely much more. Now I’m talking for the entire enchilada, not just each piece part, cause if I understand the goal, it’s going to take a massive LFP bank to harvest and store that power.
It would fit right in on for example a newer J class racer I remember reading about where they had such battery capacity that they could run their air conditioning all night.
Of course I have no idea how many millions of dollars such a boat cost, and it’s certainly not even close to a Mom and Pop, Retirement cruising boat.

I’d expect to see this kind of thing on a new 50’ Cat, where another $50K US is trivial, just another $100 a month payment or something.
Plus on a new build it would make more sense, you don’t replace a generator, you don’t buy one to start with, and you should be able to save a large amount of weight, compared to a similar usable capacity lead acid bank, cause those big Cats run around with 12 KW generators, and that’s not lightweight, on a boat that doesn’t like weight.

[john61ct]

Well **if** that does turn out to be the case, hopefully lessons can be applied to stuff we hoi polloi can afford

Originally Posted by john61ct

open hardware / FOSS projects like Thomas' will get extended into the arena using stock HO large frame alts, even if only at 24V rather than 48.

[tanglewood]

Originally Posted by Dockhead

Why do you think a 15hp alternator wouldn't create a meaningful load at idle, for a 125 hp engine?


Looks to me like the Lehman 125 produces about 30hp at idle. Even a much smaller alternator than that, should be plenty to keep that engine happy.


While underway -- 15 hp power taken off might or might be ok -- depends on the propeller curve. Certainly, that much power "moves the dial"-- that's 12% of maximum power and maybe 20% of power available at mid RPMs. Might well be too much depending on the prop.

There seem to be two objectives Re loading the main, but please correct me if I’m missing something.

While not underway, one would want to create enough load on the engine to prevent cylinder glazing, and excessive soot build up. My understanding is that to accomplish that you need to get above around 30% of full power load. And that’s full rated power, not max power available at 600 or 800 rpm. Unless the engine is small compared to the alternator load, that’s not going to happen.

The second objective, applicable regardless of the engines rpm or prop load, it to shift the engines operating load at the given rpm to run at a better bsfc. From the power and fuel curves I habe seen, that always means adding load to the engine. The only exception would be if you were running at or near full propulsion power, in which case there isn’t room to add more load, or doing so would make bsfc worse, not better. But that strikes me as a corner case that is of little concern.

I suspect that adding a 15hp load to a 125hp engine operating in its 40-60% power range would make little difference in the bsfc. But it totally depends on the fuel map for the specific engine. There might be cases where the bsfc would jump up such that the added load actually does come for free. But I’m a skeptic and would want to see the details.

The whole “hybrid” propulsion concept hinges on the same principal - that you can gain fuel efficiency by operating the engine in a more optimum bsfc region, and in doing so gain back more than you lose through all the electric conversion losses.

[tanglewood]

Originally Posted by OceanPlanet

You should watch Nigel's video.



However for boats with low loads, the system would indeed be overkill. The system makes sense for those with high loads that typically would have a generator running to keep up. In tandem with Li batteries the great reduction in charging times is a major change in on-board lifestyle.



185A @ 14V (approx 2.6kW) is not nearly enough for the boats that would use this system. 8+kW is another story, and allows moving some real energy into the batteries allowing shutting off the engine(s) for most of the time even on yachts with high AC loads.

Ok, so tell me more where and how you see this fitting in? High electric consumption while underway? So run the triskal to charge Bats, then run on bats, then recharge, etc?

[tanglewood]

Originally Posted by OceanPlanet

Good question! Some of the yachts we do systems for pull more power than my house. Obviously AirCon, but also things like dive compressors, large AC-powered reefers/freezers, etc. etc.



Some of the larger powerboats with Li batteries (Coastal Craft for instance, our batteries are standard on them) use the power assist feature of the Victron Quattros to pull from the batteries when high loads can blow the shore power breakers. So the loads can be quite high indeed.

Ok, this is more like what I’m building, and in this situation I see zero value in the triskle. High output alternators, yes. But no added value from the triskle.

[OceanPlanet]

Originally Posted by tanglewood

....run the triskal to charge Bats, then run on bats, then recharge, etc?

Exactly.

We have many clients now that run high loads (for instance, AirCon all night) off the batteries then recharge with either alts on the engines (varying from MGDC alts with external rectifiers, to American Power HPI alts) or generators that loaded up with enough AC/DC chargers to get the batteries recharged ASAP.

The new Integrel system takes the HP alt charging to another level. With one on each engine in a cat and doing away with separate generator, the amount of charging power relative to the weight is impressive.