Triskel power generation system on Distant Shores III

[jmh2002]

Their website is up with more info there: https://www.integrelmarine.com/

Here is some info about a collaboration with Volvo Penta too: https://www.integrelmarine.com/integ...-penta-france/

“The key to the Integrel system is that we manage the load extremely accurately in real-time, ensuring that our electrical load never pushes the total engine load beyond whatever we set it at – 75% normally but, as we have already said, we can control to any line” comments Ken Wittamore (Managing Director).

Following on from this, Integrel does not take off more than 65nm of torque of the engine – meaning that we are well within the manufacturer’s operational limits of the following engines:

Volvo Penta D2-50
Volvo Penta D2-55
Volvo Penta D2-60
Volvo Penta D2-75

And a graph supposedly demonstrating Propeller Load vs Optimisation Load:
https://www.integrelmarine.com/the-i...el-efficiency/



Have at it...

[a64pilot]

The propeller curve is real, it’s not some marketing magic. Any Yanmar manual shows it.
On edit, I should note though that boat is under propped, reason is the prop curve should intersect the engine curve at max RPM, it it intersects lower, your over propped, and most boats are a little over propped.
However with an average cruising boat motor that space is easily filled with a high output alternator, and if you install an Autoprop then that curve is almost filled, meaning there is much less difference and your motoring the same speed at lower RPM
To throw some numbers around, 1 hp is equal to 750W roughly, so to draw 7.5 KW takes 10 HP right?
Well if things were 100% efficient then yes that’s possible, but average alternator is I believe about 55% efficient, AC generator is more efficient I believe due to not having diodes to convert AC to pulsating DC, you see an alternator doesn’t make DC power, it’s an AC generator that runs its output through diodes to convert to pulsating DC, and it creates lots of heat doing this conversion and heat takes mucho power.
Then of course there are belt losses on top of the alternator efficiency. So it’s not unlikely that to make 7.5 KW is going to take 20 HP. There are I’m sure more efficient alternators but I believe as they get hot that efficiency drops so your back to maybe 65%? That’s a guess so don’t put much into it.

Then let’s look at the battery bank on the boat in the video, it’s a 10KW bank, pretty big bank, and I assume Lithium? If so for sake of argument let’s say we are going to discharge 90% of it, probably much deeper than you should but we’ll say we pull 9KW from it.
That’s three hours from my baby Nexgen, and maybe an hour or less from a “real” generator.
But if you discount silly loads like air conditioning and heating water, it’s way more than enough to watch TV and do pretty much anything else you want to do.

But my AIr conditioners pull 11 amps for one and about 5 for the other or 16 total. That is about 1920 watts for both, so in about 4.5 hours that battery bank is dead, and that’s not using it for any house load at all, so less than four hours. Now you can argue that well that will get you through the night and I’m sure your right, but I wake up in the morning with a dead 10KW bank.
So I still need to service those house loads and the sun is coming up and I’ll need to recharge that 10KW bank, so I’m going to have to run my propulsion motor for half the day to do that, then turn it off, and guess what? A little after dark I’ll need to crank that propulsion motor up again and run it for several hours.


Now, why can’t you do the same thing with any generator or BIG alternator and a 10KW battery bank?

[a64pilot]

Now don’t think I’m beating on this Triskel thing, I’m not.
However I am saying that to sell it as a replacement for a generator is a little bit optimistic.
Bu the real acid test is what does it cost, as one guy said if it cost half of what a generator does, well then it’s in the running, just don’t expect to replace a generator and run air conditioners etc with it, cause to do so is going to require lots of engine run time.
But for the guy who motors a lot and moves often and doesn’t run airconditioners etc., it may well be the cats meow.

Just I’d rather run a Honda every now and again and live off of Solar myself, and that keeps me completely 100% charged daily in the middle of the winter. But I don’t touch the airconditioners either, that takes the Nexgen.

[Pete7]

Originally Posted by a64pilot

I hav enough clue as to cost, but bet it’s at least as much as a stand alone generator, but I’ve never even seen one so that is just a wild guess.

A link to data would be interesting.

Some prices here for a similar theme but now a decade old:

http://www.hybrid-marine.co.uk/resou...ian+June09.pdf

Also some interesting results with and without on near identical yachts:

http://www.hybrid-marine.co.uk/resou...al+summary.pdf

[a64pilot]

Whatever it costs, I believe you can pretty much do similar with a couple of small frame high output alts, or one large frame high output alt.
You should be able to get 200 amps at 14V. That’s 2.8 KW, but it’s scalable you could get twice that probably with dual large frame alternators.
With dual alts you could either reduce field current to draw less from them total to keep from overloading the engine or maybe shut one down.

I don’t know, would Balmar’s small engine mode work to reduce it enough for motoring, and then off when at anchor?
That would be a simple answer, but I still think the Gori prop may also do it, so it’s a not too hard to solve problem.

All depends on what the Triskell costs, if rolling your own isn’t a large savings, then of course it’s not worth doing is it?

[FlyingScot]

So sailboats come under-propped from the factory? Is this to reduce drag while sailing or work better when powering directly into wind/waves (if this is even true). My new FoF props are higher pitched than my original fixed ones. This is why I ask if under-propping is typical.

Integrel website claims (up to) 25% fuel savings. That doesn't seem out of line for running one engine harder than two at low loads. But this can be very specific to use case.

How does Integrel the adjust for high load situations on older engines (pre canbus)?

How does adding folding/feathering props change the calculations.

Edit: Upon further research it looks like prop power and engine power match at maximum RPM.

[a64pilot]

Who knows how they come from the factory? Not trying to be sarcastic but who really knows, assumption is they are close to being correctly propped, but if you load a boat down for cruising, your likely slightly over propped.
Most cruisers who understand what and why and that have replaced props usually over prop a little. For example I’ll only turn 3300, maybe 3400 at full throttle as opposed to the 3600 that is my engines max. I do this to raise that propeller arc up closer to the engine arc, knowing full well that I’m reducing my max power available and should never probably exceed say 3000 RPM continuous, but I never, ever do that. But I know I can go to full throttle for several minutes if I have to, but never have had to.
That and my Autoprop which is a self adjusting pitch prop brings I believe my propellor arc pretty close to the engine arc.

Claiming fuel consumption being less than I assume running a generator is I hate to say fantasy, by that I mean what do you want the numbers to be? If you want the numbers to show good, then you take a big generator and only draw a little power from it, say a 10KW hen but only pull 2 KW, then pull 2 KW from the motor. There are just too many variables you can play with to get what you want.
You want to save 25% fuel burn, slow down a kt, maybe 2 tops.
Of course you can pull 10 kw from the generator and if you try to pull a lot of power from the motor while motoring you’ll eventually damage it.

[a64pilot]

This is the chart from my Yanmar’s manual, an old 4JHE. This is not for an actual prop, but for the theoretically perfect prop.
You’ll notice that the engine an prop curves cross at 3500, which is the max continuous power for my engine, it’s rated at 40 HP at 3500 continuous, 44 HP at 3600 for one hour.

[Auspicious]

I'm catching up with this thread so I'm dipping to some older posts.

Originally Posted by Dockhead

On a catamaran, I would for sure go this way -- having THREE diesel engines on a weight-sensitive unballasted vessel is pure madness.

I'm not sure I agree. I haven't run the numbers here, but based on experience with sub tenders I'd start thinking about four. On one power boat we replaced two generators with three and came out ahead on weight. The big deal is frequeny syncrhonization. The concept is diesel-electric. Four 8 kW generators that can be run in any combination, all identical, works well. I think that works well on a catamaran.

Originally Posted by Dockhead

As some one who absolutely cannot fit solar anywhere, I have to disagree with this. There are absolutely many use cases where a significant amount of solar power is not possible.

I agree with you that "enough" solar is really hard and comes with its own trade-offs. It is the best non-fossil source of energy for cruising. Let no one fool themselves: PV solar power is neither green nor renewable. The materials necessary to make panels are mined and as limited as anything else. The mining process is environmentally horrid and the manufacturing process is no better. Neither is the recycling/disposal process. An overwhelming majority of the rare earth minerals are owned by China if you care about such things.

Originally Posted by Dockhead

Redundancy is a very good thing with critical systems like these, but it's not the only way to achieve reliability, which is the final goal.

I worry most about failure cascades. One thing fails and another fails and suddenly an inconvenience becomes a crisis. Redundancy really does help. Story: Lost a battery bank due to one battery with an internal short that took down the whole bank. Headed back to port running the generator. Generator failed. Alternator on main engine failed. We sailed into Ft Lauderdale two days later with no electronics (nav on my phone charged from the engine start battery). TowboatUS met us and shadowed us through some drawbridges. I was a little busy to look up phone numbers for bridges and TowboatUS short circuited the "is it really an emergency?" discussion. It's just one data point. Not statistically significant. It's just an example of what can happen with multiple failures.

This makes me nervous.

Originally Posted by john61ct

Yes of course. Personally, charging is my only load for mains or AC genset.

That's a choice and not everyone's. Aircon is important to me. Other people want laundry or electric cooking. Hot water. The electrical loads can be high.

Originally Posted by john61ct

I plan the same, likely CruiseRO 40+gph, but DC powered.

Not my choice. You really can't beat the customer service from Rich Boren but the documentation is poor and some of the hardware has shortfalls.

[stormalong]

A product like this is unlikely to sell well. It will end up being discontinued or the company will go belly up. There will be no support and you will end up throwing it in the dumpster. This happens so often with this kind of product that I would not risk my money on it.

While I might buy the 1000th one I would not buy any sooner than that.

[a64pilot]

If it’s not ungodly expensive, it may well be the next great thing.

[stormalong]

Originally Posted by a64pilot

If it’s not ungodly expensive, it may well be the next great thing.

The fact that they still have not released a price means that it will be ungodly expensive.

[mcarthur]

This website shows A$18,000 excluding installation, excluding battery pack and excluding charger. That's US$12,500 or so.

This website shows 18,000gbp including the battery pack and presumably charger. That's US$23,300.

Those are pretty big numbers for the equivalent of a 6-7kW genset. They're slightly better than a pure DC genset, but more than an AC. Definitely not something just to install because you'd like to try it! But if your genset is dead, and you have a small motor, it may well be worth the weight/space savings - and there may even be fuel/$ savings too.

• Genset working now? Don't change it unless you have big $ and you have very weight sensitive multihull.
• Mid-large motor(s)? Don't do it - go with large alternator(s) at about $2-4,000.
• Sailing boat with small motors, no genset or nearly failing... - it becomes a possible choice.

[a64pilot]

To just throw a number out there I believe I have about $6,000 in my Nexgen 3.5 and it weighs 200 lbs all in, no extra battery pack, just the house bank.
Figure about maybe $4,500 to replace as I have all the extras, panels, sound enclosure, exhaust, fuel pump etc now. And that’s if I don’t want to rebuild it, it’s a wet sleeve single cylinder Kubota that has a ball bearing crank, so a sleeve and piston and rings, have the valves done and it’s a new motor.
It’s a very widely available little agricultural motor so maybe a couple hundred to rebuild?
Fuel burn is one quart an hour, so of course four hours to the gallon.

[a64pilot]

Originally Posted by mcarthur

This website shows A$18,000 excluding installation, excluding battery pack and excluding charger. That's US$12,500 or so.



This website shows 18,000gbp including the battery pack and presumably charger. That's US$23,300.



Those are pretty big numbers for the equivalent of a 6-7kW genset. They're slightly better than a pure DC genset, but more than an AC. Definitely not something just to install because you'd like to try it! But if your genset is dead, and you have a small motor, it may well be worth the weight/space savings - and there may even be fuel/$ savings too.

• Genset working now? Don't change it unless you have big $ and you have very weight sensitive multihull.
  
• Mid-large motor(s)? Don't do it - go with large alternator(s) at about $2-4,000.
  
• Sailing boat with small motors, no genset or nearly failing... - it becomes a possible choice.
  

I disagree, don’t put it on a small motor, you’ll easily overload it, on a small motor it would only be useful at anchor, it takes a big motor to be able to extract the 10 to 20 HP to run it without being overloaded while motoring