Triskel power generation system on Distant Shores III

[Aeolus6]

I find this proposal fascinating.

I've listen to Nigel for years.

25 years ago, as a doctor familiar with emergency vehicles, I equipped my VW powered 43' A & R Yawl with an engine driven alternator that yielded 4.0 KW of 110ACV at 60 Hz + or - 0.25 Hertz that was designed to operate frequency sensitive electro cartographic recorders on ambulances.

In 25 years, it never failed.

I think Nigel has got the answer.

Now, lets look at costs.

My 4.5 Kw alternator, solid state control box and display cost me a total 0f $900 in 1992?

[DeepFrz]

Originally Posted by BigBeakie

Stepping down can be done but the limiting factor is the amp draw of these devices. If you're running electric winches & windlass at 24v, they cannot keep up. Custom made ones from Germany & US used in military are prohibitively expensive.

Which winches and windlass are 48v ??? All my searches turned up were trailer and 4x4 winches.


Sent from my iPad using Cruisers Sailing Forum

Yes, you seem to be right. My bad for assuming.

[tanglewood]

I'm curious how this device appeals to people. Is it:


- The idea of a really big main engine alternator? And if so, is it for faster battery charging, or for running larger loads while underway?


- The idea of alternator load control beyond that already afforded by a charge controller? A conventional controller can and will apply max load, limited by the alternator's capacity or the battery's acceptance rate. So the incremental value of this new device is reducing load when the combination of propulsion and alternator are too much. Is that really an issue?


- The idea of getting rid of a generator, understanding that you will instead be running the main engine in place of the generator?

- The idea of better fuel efficiency, presumably by virtue of running at 48V and the contributions of the control system.


Something else?

[Dockhead]

Originally Posted by tanglewood

I'm curious how this device appeals to people. Is it:


- The idea of a really big main engine alternator? And if so, is it for faster battery charging, or for running larger loads while underway?


- The idea of alternator load control beyond that already afforded by a charge controller? A conventional controller can and will apply max load, limited by the alternator's capacity or the battery's acceptance rate. So the incremental value of this new device is reducing load when the combination of propulsion and alternator are too much. Is that really an issue?


- The idea of getting rid of a generator, understanding that you will instead be running the main engine in place of the generator?

- The idea of better fuel efficiency, presumably by virtue of running at 48V and the contributions of the control system.


Something else?

I think it's 1 through 3. I don't think 4 is really material. The difference in fuel consumption will not be even measurable, I suppose. The main benefit of 48v will be in the wiring.

If the alternator is big enough, it can put enough load on the main engine to be healthy running it just for charging, something you can't really obtain from a car-type alternator.

As to control - I guess some people want this automated. I would be happy, personally, with a manual control like the Balmar "belt saver". It may be, however, that a really large alternator cannot be turned down sufficiently by the Balmar.

[Dockhead]

Originally Posted by Fuss

.. . are you saying with this stuck on a motor we can have induction, washer dryer, microwave... i doubt it.... and if not. why buy it....

I run induction, washer, dryer, and microwave off my cheap, standard 24v Leece Neville via a 3kW Victron inverter. Not all at once, obviously, but the alternator will produce 2kW all day long without breaking a sweat.

This setup should be capable of still much more.

[Q Xopa]

Originally Posted by tanglewood

I'm curious how this device appeals to people. Is it:


- The idea of a really big main engine alternator? And if so, is it for faster battery charging, or for running larger loads while underway?


- The idea of alternator load control beyond that already afforded by a charge controller? A conventional controller can and will apply max load, limited by the alternator's capacity or the battery's acceptance rate. So the incremental value of this new device is reducing load when the combination of propulsion and alternator are too much. Is that really an issue?


- The idea of getting rid of a generator, understanding that you will instead be running the main engine in place of the generator?

- The idea of better fuel efficiency, presumably by virtue of running at 48V and the contributions of the control system.


Something else?

Thats most of it.

However when you are referring to 'Load' regulated by Charge controller or Aternator regulator.This is regulating the voltage from our Alternator to the batteries to optimise the battery charging.

Of course this is needed as usual.

However this system is also will 'regulate' (reduce) alternator to optimise the engine load. As you say to keep the engine total load in its optimum (most efficient fuel) Torque range for a given RPM for as much as possible.

As you are saying there are a lot of 'IFs' when this is possible or applicable-
The Alternator is big enough to load up the engine enough.
The batteries can accept that much charge etc.

In this case the Alternator is not big enough to load up the engine enough at anchor. Ie with a 4JH4-TE 75 HP eng it would want around 50 hp/ 40 kWs at 1800 to 2000 RPM.

This could theoretically recharge a 10kWH LFP bank (around an 24v 400 AH/ 12v 800 AH) from 80% DOD, in around 15 mins. Again a lot of ifs in a scenerio like that.

Talk about reduced generator run time. The overall fuel use for power produced should be quite good.

Obviously scheduling as many high consumption loads- induction cooker, water heater, water maker, air cond, washing machine etc at the same time would make this more manageable.

The Distant Shores III had Gels (I think) which could only suck up so much charge for so long. So wouldnt load up the Alternator and thus the engine for very long.

Ideally a Bigger Alternator and big LFP batt bank to get the best from this concept. Of course easier said than done.

There wouldnt be many boat set ups that could practically use much of this funtionality for much of the time.

Motoring on passage this is more 'usable'. However I think motoring is mostly reasonably stable RPMs and loads so could be easily done manually mostly.

But no doulting this is cleverly developed and clearly contributing to advancing our boating technology.


Im all for this and waiting eagerly for watch how this progresses.

[Dockhead]

Originally Posted by Q Xopa

. . .

In this case the Alternator is not big enough to load up the engine enough at anchor. Ie with a 4JH4-TE 75 HP eng it would want around 50 hp/ 40 kWs at 1800 to 2000 RPM.

. . .

A 75hp diesel does not need a 50hp load to be healthy.


The load required for healthy operation depends on RPM -- and it just needs to be enough to heat up the cylinders, and that amount varies according to the amount of air flowing through the cylinders, which is a direct function of RPM.


At 1200 RPM or so I don't think you need more than 5hp or so, in an engine that size.


I do not think it is unrealistic at all to use a main engine at anchor to run a big alternator. The key thing is to have batteries which accept enough power to keep the alternator going full blast. Here is where lithium may be worth its weight in gold.

[tanglewood]

Originally Posted by Dockhead

I think it's 1 through 3. I don't think 4 is really material. The difference in fuel consumption will not be even measurable, I suppose. The main benefit of 48v will be in the wiring.

If the alternator is big enough, it can put enough load on the main engine to be healthy running it just for charging, something you can't really obtain from a car-type alternator.

As to control - I guess some people want this automated. I would be happy, personally, with a manual control like the Balmar "belt saver". It may be, however, that a really large alternator cannot be turned down sufficiently by the Balmar.

Thanks.


Given that, it begs the question of how it's better than installing a same-sized alternator + Balmar or other regulator? That would get you the same power, so address #1 and #3. As for #2 and optimizing engine load, it seems in 90% of the cases you would want to apply more load to the main, not less. A Balmar will always apply max load, so under the 90% scenario it would be the same. And it seems the only time you would want to reduce main engine load is when running full tilt for propulsion and adding alternator load would overload the engine. Does that happen often? I know trawlers, and you virtually never run at full power, so there is ALWAYS room for as much alternator load as you can apply. The limit is really only the manufacturer's allowed belt loads. Do sailing vessels often run at full throttle when motoring?

[Dockhead]

Originally Posted by tanglewood

Thanks.


Given that, it begs the question of how it's better than installing a same-sized alternator + Balmar or other regulator? That would get you the same power, so address #1 and #3. As for #2 and optimizing engine load, it seems in 90% of the cases you would want to apply more load to the main, not less. A Balmar will always apply max load, so under the 90% scenario it would be the same. And it seems the only time you would want to reduce main engine load is when running full tilt for propulsion and adding alternator load would overload the engine. Does that happen often? I know trawlers, and you virtually never run at full power, so there is ALWAYS room for as much alternator load as you can apply. The limit is really only the manufacturer's allowed belt loads. Do sailing vessels often run at full throttle when motoring?

To answer the begged question -- other than automation, I don't see anything which can't be done with a Balmar, unless the Balmar has an insufficient range of modulation to turn down a really big alternator.


But you are missing something about running a big alternator while motoring -- full throttle has nothing to do with it. Diesel engines -- look at your manual, at the power curve -- cannot produce maximum power at any given RPM. There is a different maximum power figure for any given RPM. Now look at the propeller curve -- the propeller likewise does not absorb the same amount of power, at different RPMs.


So what is available to run a big alternator is ONLY the difference, at any given RPM, between the propeller curve and the engine power curve. Since most big alternators don't have a flat output curve -- they ramp up quickly to near maximum power -- you do run the risk at low RPMs while motoring of overloading the main engine. ESPECIALLY with a variable pitch prop (like mine) which pitches up at low RPMs to put more load on the engine. You need to be able to turn the alternator down to avoid this.


The "throttle" on diesel engine is actually not a throttle at all -- it is a governor control, which sets the RPM at which the governor will attempt to keep the engine going at. If the revs fall below the set RPM, the governor will increase the amount of fuel injected. So if your 100 hp engine (say) is capable of producing 50hp at say 1800 RPM, but your prop only needs 30 hp, you've got 20 hp to spare, but you probably don't want to use all 20 hp, because the engine -- if it's not a common rail one -- will start to get smoky and run less efficiently near maximum possible output, especially at low RPMs. That's why the prop curve is matched to the engine power curve in a way which leaves a certain amount of headroom. You can use some of that headroom for power generation, but not too much.

[tanglewood]

Originally Posted by Q Xopa

Thats most of it.

However when you are referring to 'Load' regulated by Charge controller or Aternator regulator.This is regulating the voltage from our Alternator to the batteries to optimise the battery charging.

Of course this is needed as usual.

However this system is also will 'regulate' (reduce) alternator to optimise the engine load. As you say to keep the engine total load in its optimum (most efficient fuel) Torque range for a given RPM for as much as possible.

As you are saying there are a lot of 'IFs' when this is possible or applicable-
The Alternator is big enough to load up the engine enough.
The batteries can accept that much charge etc.

In this case the Alternator is not big enough to load up the engine enough at anchor. Ie with a 4JH4-TE 75 HP eng it would want around 50 hp/ 40 kWs at 1800 to 2000 RPM.

This could theoretically recharge a 10kWH LFP bank (around an 24v 400 AH/ 12v 800 AH) from 80% DOD, in around 15 mins. Again a lot of ifs in a scenerio like that.

Talk about reduced generator run time. The overall fuel use for power produced should be quite good.

Obviously scheduling as many high consumption loads- induction cooker, water heater, water maker, air cond, washing machine etc at the same time would make this more manageable.

The Distant Shores III had Gels (I think) which could only suck up so much charge for so long. So wouldnt load up the Alternator and thus the engine for very long.

Ideally a Bigger Alternator and big LFP batt bank to get the best from this concept. Of course easier said than done.

There wouldnt be many boat set ups that could practically use much of this funtionality for much of the time.

Motoring on passage this is more 'usable'. However I think motoring is mostly reasonably stable RPMs and loads so could be easily done manually mostly.

But no doulting this is cleverly developed and clearly contributing to advancing our boating technology.


Im all for this and waiting eagerly for watch how this progresses.

It would be interesting to see this overlaid on a real engine's fuel map. I can see how it would be more interesting as the engine size gets smaller relative to alternator load. In that case you have a chance of moving the engine operating point enough on the fuel map to make a difference. Our main is 400hp, and even the 11kw of alternator capacity we have won't move the operating point in any significant way. But if your engine sizing is such that it can, the question then remains whether it's a more fuel efficient operating point than a near fully loaded genset engine, and whether that savings (assuming there is one) is more than the still greater electrical losses generating via a 48V alternator vs a 230V generator.


The whole comparison is probably too hard to demonstrate concretely, so everyone will just believe what they want to believe.

[Q Xopa]

Originally Posted by Dockhead

A 75hp diesel does not need a 50hp load to be healthy.


The load required for healthy operation depends on RPM -- and it just needs to be enough to heat up the cylinders, and that amount varies according to the amount of air flowing through the cylinders, which is a direct function of RPM.


At 1200 RPM or so I don't think you need more than 5hp or so, in an engine that size.


I do not think it is unrealistic at all to use a main engine at anchor to run a big alternator. The key thing is to have batteries which accept enough power to keep the alternator going full blast. Here is where lithium may be worth its weight in gold.

No of course 50 HP isnt needed to be healthy. Lets face it far less than that happens all the time. In fact I would say it would be rare to be the case. And as you say engines live quite happily.

That is just the 'optimum' Torque curve that this concept is trying to get closer to. And 50 HP is an off the top of my head figure for 2000 RPM. Which is, again from memory, around the top of the Torque curve so quite an efficient running RPM.

As you correctly say 1200 RPM would be lower HPs. But also not as efficient.

This is all a question of degrees. And practically speaking from an efficiency perspective its not viable to chase this small improvements.

This set up is far closer to the ideal than I would say most, if not all of our current setups are.

But to requote someone obviously wiser than myself "perfect is the enemy of good".

Im not saying its not good. I think it is very good.

[tanglewood]

Originally Posted by Dockhead

To answer the begged question -- other than automation, I don't see anything which can't be done with a Balmar, unless the Balmar has an insufficient range of modulation to turn down a really big alternator.


But you are missing something about running a big alternator while motoring -- full throttle has nothing to do with it. Diesel engines -- look at your manual, at the power curve -- cannot produce maximum power at any given RPM. There is a different maximum power figure for any given RPM. Now look at the propeller curve -- the propeller likewise does not absorb the same amount of power, at different RPMs.


So what is available to run a big alternator is ONLY the difference, at any given RPM, between the propeller curve and the engine power curve. Since most big alternators don't have a flat output curve -- they ramp up quickly to near maximum power -- you do run the risk at low RPMs while motoring of overloading the main engine. ESPECIALLY with a variable pitch prop (like mine) which pitches up at low RPMs to put more load on the engine. You need to be able to turn the alternator down to avoid this.


The "throttle" on diesel engine is actually not a throttle at all -- it is a governor control, which sets the RPM at which the governor will attempt to keep the engine going at. If the revs fall below the set RPM, the governor will increase the amount of fuel injected. So if your 100 hp engine (say) is capable of producing 50hp at say 1800 RPM, but your prop only needs 30 hp, you've got 20 hp to spare, but you probably don't want to use all 20 hp, because the engine -- if it's not a common rail one -- will start to get smoky and run less efficiently near maximum possible output, especially at low RPMs. That's why the prop curve is matched to the engine power curve in a way which leaves a certain amount of headroom. You can use some of that headroom for power generation, but not too much.

Yup, I totally get prop curves, max power curves, the gap between the two, and governors. Your examples are very helpful showing where an alternator can overwhelm a propulsion engine on a sail boat. Those situations just don't happen in a trawler. It's confirmation that this becomes more interesting as the alternator load becomes a more significant portion of the main engine's total capacity.

[Dockhead]

Originally Posted by tanglewood

Yup, I totally get prop curves, max power curves, the gap between the two, and governors. Your examples are very helpful showing where an alternator can overwhelm a propulsion engine on a sail boat. Those situations just don't happen in a trawler. It's confirmation that this becomes more interesting as the alternator load becomes a more significant portion of the main engine's total capacity.

Indeed. I guess on a trawler with big propulsion engines this is a much bigger challenge. It would be very interesting to know objectively how much load is required on any given engine for adequate cylinder temp. I guess it could be measured with EGT?


I read somewhere that it's 275F. Note that many trucks have exhaust back pressure valves (EBPV's) which create back pressure artificially to create a load on the engine at idle to prevent wet stacking.

[tanglewood]

Originally Posted by Dockhead

Indeed. I guess on a trawler with big propulsion engines this is a much bigger challenge. It would be very interesting to know objectively how much load is required on any given engine for adequate cylinder temp. I guess it could be measured with EGT?


I read somewhere that it's 275F. Note that many trucks have exhaust back pressure valves (EBPV's) which create back pressure artificially to create a load on the engine at idle to prevent wet stacking.

Engine loading isn't a big issue for most displacement speed trawlers. But the engines are still bigger than for a similar sized sail boat. The bigger problem are planing boats that get run at displacement speeds for extended time, essentially operating at slightly above idle speed. And older engines are more of an issue than newer common rail or other higher pressure injection. But I think in all cases there is always plenty of
"room" between the prop load and engine's max output capability at any given rpm to drive whatever alternator you want to throw at it. So you are always only looking to increase load, never to decrease it.


That said, I did encounter an engine overload at idle. The boat has hydraulics powered off the main & generator, but prioritized to load the main as much as possible because it always (almost always, it turns out) has plenty of power. With the windless raising the anchor, and high volume anchor wash running (both hydraulic), plus a full load on the alternator charging house batteries after a night at anchor, you couldn't get the engine to rev up above idle. You could put it in gear to move forward towards the anchor, but it couldn't build up RPMs. Reduce any of the loads just a bit and it was fine. And once rpms were built up a bit, it had all the power you could want.

[john61ct]

Originally Posted by tanglewood

a chance of moving the engine operating point enough on the fuel map to make a difference. Our main is 400hp

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.