Triskel power generation system on Distant Shores III

[noelex 77]

Originally Posted by Fuss

I have a 135hp 6 cylinder with 3 24v alternators 110ah and 55ah running off the front pulley and 70ah running off the propshaft all contributing to a 650ah battery bank if I run the engine.
If I am sailing then only the propshaft alternator contributes.

I don't see how the Triskell improves on this.

If mine breaks, It has some redundancy.

Thanks for the details.

That is about 4kw from the front of the engine and a further 1.5 kw from the propshaft. 135hp is larger than my main engine but that is still very impressive.

Do you monitor EGT? Are there any management problems? How old is the system? Do you dial the output down for example if motoring into a strong wind and head-sea?

I agree about the many advantages over the Triskel system such redundancy, ease of repair and simplicity all at a much lower cost. I would not have thought this amount of electrical power could be extracted reliably from such a simple system that has to also function providing propulsion, but obviously it has worked in your case.

[Dockhead]

Well, several issues raised here:


1. How much power can you produce with a heavy duty alternator?


2. Is this limited by the belt or drive system?


3. Is this limited by managing mechanical power available from the main engine?


4. And how much power do you need, anyway?




Starting with last first:


4. Remember that DC power put into a battery bank and then inverted to power AC loads has inherent Power Boost. The DC power being put in does not need to equal the peak loads; just the average ones. I find that 2.5kW works fine for my loads, even with electric cooking, washing, drying, etc. When you're using that gear you won't be adding much power to the batteries, is all. Obviously if you could charge batteries AND run your AC gear that would be better. But there's no question about simply running it -- 2.5kW is better than a 10 amp shore power connection.




1. Heavy duty alternators, in total contrast to car-type alternators, are rated at the power they are designed to produce continuously. I don't think they need to be derated by 50% unless you've got a belt issue (see Question 2). I run mine at 100% rated output for hours on end without issues. If your alternator is rated at 4kW I would, if I were you, be happy to run it at that, or if you want to be really conservative, derate to 80% or 90%.


2. Drive/belt systems have their own ratings. If you're designing from scratch, I don't believe it is a big problem to specify a drive system capable of transmitting 4kW or 5kW.


3. I don't think you need a $20k Triskell system to deal with the "available mechanical power from the engine" issue. Taking 4kW or 5kW from a reasonable size main engine should not be an issue until you get to something well over cruising speed. You don't need to guess; just take your propeller curve and see for yourself. The KISS solution to this is to just take the bog standard off shelf Balmar regulator with the helm-mounted "small engine mode" switch. If you know you're going to be running over X RPM, you just flip the switch. If you forget, you'll hear the engine bog, and then you'll remember. I don't think this is rocket science. This could be regulated automatically, and that also wouldn't be difficult to implement, but i wouldn't even bother, I don't think.




As Noelex mentioned, one absolutely massive advantage of using a simple school bus alternator is the extreme simplicity, cheapness, and repairability of such devices, in dramatic contrast to typical separate gensets. I carry an entire spare alternator on my boat; in case of need I can swap it out in 30 minutes, then have the bad one repaired at any third world auto electric shop in the next port. Or fix it yourself; they are exceedingly simple.

[darylat8750]

Noelex said "
The second problem is extracting 8+kw via a belt from the main engine crankshaft, especially via a pulley mounted a long way forward, as most alternator aftermarket conversion kits do. Once again you need a managment system with soft start and ramp up to control the torque with variable demands. Some means of reducing the side loading is needed or at least some engineering calculations to check the load is acceptable for that particular engine. In practice, I suspect the only reliable DIY approach to generate this type of power would be from the prop-shaft or lay shaft suitably supported. "

I think the concern about side loading the front main bearing is misplaced. The normal running forces on the main bearing of diesel engines of 4 cylinders or less are way more than any belt (normally used for alternators) can tolerate for even a short period of time. If Volvo would approve that installation (referred to in post 329) my thought is that concern should be laid to rest.

If I were building new I would use a 24V system and would be inclined to put one of the large frame alternators on the front of the engine and another one on a PTO on the gearbox. With a large solar set up to provide normal everyday electrical loads I think even the occasional air conditioning loads could be handled. At this point the calculations have been done on my fingers and toes so YMMV.

[Dockhead]

One thing I would add to what I wrote earlier:


Designing a custom control system which would automatically regulate the output of alternator or alternators to avoid overloading the main engine would probably not be all that difficult.


But as I said, I wouldn't personally care about this, and wouldn't mind regulating the system manually. Besides remembering to turn down the power over a certain RPM while motoring, you could also install an EGT gauge with alarm, as an additional reminder. There is a PGN for EGT in NMEA2000, so it would be dead simple to program a network alarm for a certain EGT.


Another thing one could do is install two, not one, school bus alternators. Maybe on opposite sides of the engine to reduce crankshaft side loading. Have a switch to turn them on and off. Just don't switch on the second one when you're motoring above a certain RPM.


I think all this is not hard at all to set up and manage, and a really KISS system could be implemented which would be really cheap, reliable, and easy to use. The Triskell system is nice and all, but query whether it is not solving a problem which is not really such a big problem, and adding undesirable complexity and proprietary parts.


To regulate manually, all you would need to do is calculate at what RPM the unused power between the prop curve and the engine max power curve is less than 120% (or whatever) of the max power used by the alternator at that speed, taking into account your gearing of the alternator. Then verify this with EGT measurements.


Then you just laminate a card and put it next to your "small engine mode" switch at the helm, which says "Turn Off When Motoring Above 2600 RPM" [or whatever RPM].


Who needs and automatic control and associated proprietary parts? Then a bog standard off the shelf Balmar regulator would be perfectly adequate.


Keep on board a spare complete alternator, good supply of belts and spare alternator parts, including pulleys (don't ask me how I know you need to have these on board ), and a spare regulator on board, and for less than 1/10th of the price of the Triskell system, you have absolutely bulletproof power system which will just about 100% guaranty you that so long as your main engine runs, you will have power. This is a pretty compelling proposition, IMHO. If on top of that you have a separate generator, then you have reduced the risk of being without power to almost zero.




I struggled with this very question last year when I was planning to be above the Arctic Circle for most of the summer and could not afford to take any material risk of being without power. I thought about it a lot. I considered buying a new Honda generator as a backup to my backup and keep it on board just in case all else failed.


In the end I settled on the complete spare alternator, spares kit, belts, pulleys, and a very good spares kit for the generator. Plus spare inverter, spare battery charger.


In the event none of this was needed -- the heavy duty generator, used for several hours every single day, never skipped a beat, nor did the alternator give any trouble. But of course having the spares on board is what directly prevented any failures -- according to Sailor's Reverse Sod's Law [Sailor's Sod' Law is, of course, that whatever you don't have a spare for, will break, and at the worst moment].

[wingssail]

Originally Posted by Dockhead

I carry an entire spare alternator on my boat; in case of need I can swap it out in 30 minutes, then have the bad one repaired at any third world auto electric shop in the next port. Or fix it yourself; they are exceedingly simple.

Being as we do all of our charging with the main engine (aside from a bit of solar) and have done so for MANY years, very often in quite off-the-beaten-path locations, we have some experience with this.

Our favorite alternator is a Balmar type 90 (130 amp). It is powerful and withstands heat well (and runs cooler than our Balmar 110). I bought it directly from Balamar at a Fisheries Supply swap meet in 1993. However it has burned out a few times over the years. (I have jacked up the output with advanced programming, so this is on me). Twice, once in Sumatra and once in Mexico it was re-wound with the wrong size wire and did not produce sufficient power afterwards. When your alternator shop is a 12'x12' wooden shack with a dirt floor and a counter top as black as charcoal, don't plan of the guy having exactly what is needed for your high output alternator. And maybe you don't want to wait three months until you're going to be in a city somewhere.

So we carry three alternators and two spare regulators and a selection of belts.

Originally Posted by Dockhead

4. And how much power do you need, anyway?

We feel like we have a luxurious boat, (comforts, conveniences, good refer and freezer, running hot and cold water, and plenty of useful appliances, not camping out) though few would think so, but it is actually simple simple simple and our electrical needs are really quite few. 1.5Kw is plenty for us unless docked and using the air con (we don't use it except on shore power).

If one thinks they need to carry all the comforts of their condo in Lauderdale, plus spares and back-ups for self sufficiency, including use of 8KW of onboard power, to the point of having to motor everywhere because their boat can't any longer sail, I advise them to stay out of remote places AND plan on spending a lot of time fixing things.

Originally Posted by a64pilot

So to put all your electrical generation capacity in your propulsion engine is asking for trouble.

Not necessarily, and it sure beats having 2-3 engines onboard, in my opinion, from a weight and simplicity point of view. We want the weight in payload, not excessive equipment. Our engine trouble has been non-existent but we SAIL everywhere.

Plus, here is another thought: With all the equipment on board where do you put provisions? We carry food for a few months, 140 gal of water and 60 gal of fuel, water maker, a fully equipped workshop including sewing station, sails for racing and cruising (12 -14 total) plus sailcloth and canvas, and all of our worldly belongings, including paper records for 35 years, three photography systems, 3 computers, printer, scanner, window unit air conditioner, and loads of other stuff, and spares for Africa and NOTHING is on deck or on the cabin sole. AND we still win races. This is a 43ft boat.

But we only sleep comfortably two people, more than that need to bunk in the main cabin or live in the dark hole of Calcutta which is our forward cabin.

It's all about choices and preferences.

[Dockhead]

Originally Posted by wingssail

Being as we do all of our charging with the main engine (aside from a bit of solar) and have done so for MANY years, very often in quite off-the-beaten-path locations, we have some experience with this.

Our favorite alternator is a Balmar type 90 (130 amp). It is powerful and withstands heat well (and runs cooler than our Balmar 110). I bought it directly from Balamar at a Fisheries Supply swap meet in 1993. However it has burned out a few times over the years. (I have jacked up the output with advanced programming, so this is on me). Twice, once in Sumatra and once in Mexico it was re-wound with the wrong size wire and did not produce sufficient power afterwards. When your alternator shop is a 12'x12' wooden shack with a dirt floor and a counter top as black as charcoal, don't plan of the guy having exactly what is needed for your high output alternator. And maybe you don't want to wait three months until you're going to be in a city somewhere.

So we carry three alternators and two spare regulators and a selection of belts.



We feel like we have a luxurious boat, (comforts, conveniences, good refer and freezer, running hot and cold water, and plenty of useful appliances, not camping out) though few would think so, but it is actually simple simple simple and our electrical needs are really quite few. 1.5Kw is plenty for us unless docked and using the air con (we don't use it except on shore power).

If one thinks they need to carry all the comforts of their condo in Lauderdale, plus spares and back-ups for self sufficiency, including use of 8KW of onboard power, to the point of having to motor everywhere because their boat can't any longer sail, I advise them to stay out of remote places AND plan on spending a lot of time fixing things.

Not necessarily, and it sure beats having 2-3 engines onboard, in my opinion, from a weight and simplicity point of view. We want the weight in payload, not excessive equipment. Our engine trouble has been non-existent but we SAIL everywhere.

Plus, here is another thought: With all the equipment on board where do you put provisions? We carry food for a few months, 140 gal of water and 60 gal of fuel, water maker, a fully equipped workshop including sewing station, sails for racing and cruising (12 -14 total) plus sailcloth and canvas, and all of our worldly belongings, including paper records for 35 years, three photography systems, 3 computers, printer, scanner, window unit air conditioner, and loads of other stuff, and spares for Africa and NOTHING is on deck or on the cabin sole. AND we still win races. This is a 43ft boat.

But we only sleep comfortably two people, more than that need to bunk in the main cabin or live in the dark hole of Calcutta which is our forward cabin.

It's all about choices and preferences.

Yeah, it's all about choices and preferences indeed. Like so many things.


I think the big watershed issue is aircon. If you need to use that off shore power, then you need a heavy duty continuous duty rated generator. That really drastically changes the daily power budget and correspondingly the optimum architecture of the power system.


Without aircon, I think almost anyone could get by using the main engine. A separate generator adds some redundancy and adds some convenience. But the main engine is something you count on to run no matter what, right? So I'm not sure it's "asking for trouble" to rely on it entirely for power. Reducing the number of diesel engines on board can have profound effects on weight and cost, both capital and running costs. I think it could make sense for a lot of us.


And by the way, if I were running a catamaran which already has two propulsion engines, and to boot is more weight sensitive than our monos, there is no way in hell would I have a third diesel engine on board.

[noelex 77]

Originally Posted by Dockhead

Another thing one could do is install two, not one, school bus alternators. Maybe on opposite sides of the engine to reduce crankshaft side loading. Have a switch to turn them on and off. Just don't switch on the second one when you're motoring above a certain RPM.

I think that would be an excellent system. As you would (presumably) be eliminating the starting battery alternator, this would require a system for charging the start battery, but that is not difficult to arrange, even with a 24v house bank.

The only trade off is the system does complicate the main engine (as does the Triskel system which would be one of my primary objectons). Simple is often associated with reliable in the marine environment. I have fitted a second large frame alternator to my main engine so I have already violated this principle , but it is a concept that is worth some consideration.

There are plenty of ways to generate or save power, but a reliable main engine is priceless .

[a64pilot]

Several issues, first Nolex keeps saying generators are unreliable, maybe it’s the electrical part he’s referring to? If so the Triskel is at least as complex with I’d bet zero spare parts availability without going to the manufacturer, but as far as reliability of a generator I don’t get it, mine for example is a simple basically agricultural single cyl Diesel that’s cooled by thermal siphon, not even a water pump and thermostat to worry about. It can’t get any simpler than that. Voltage regulation is through a capacitor, no electronics.
No reason a generator ought to be any less reliable than your propulsion motor, but I’d bet on average they are poorly maintained and run for many more hours than a propulsion motor. Many run a generator nearly continuously.

You can extract as much power as you want from a belt system within reality, I learned to fly a helicopter that its 200 HP engine drove the rotor system though belts. The Triskel is belt driven. Belts properly sized aren’t an issue.

Then we talk about weight, what do you think the Triskel and it’s 10KW battery bank weighs? My Generator and it’s sound enclosure is 200 lbs.
I bet it’s a wash or my Generator is less.

You can easily pull 4KW from a couple of big alternators, but if you take Air conditioning out of the equation, why would anyone need more than 2 KW?
That’s 142 amps at 14V, you can’t run your boat and charge your batteries off of 142 amps?

But the real problem is if you need mucho power and your Triskel breaks, what’s your back up plan? Better have a Honda on board, or good Solar or both. Alternators you can carry spares or have overhauled and of course use your generator until you do, generator breaks, use the alternators.

The Triskel is a single point of failure, and would seem to have some complex electronic controls.

[wingssail]

Originally Posted by a64pilot

...Better have a Honda on board..

Or better yet, two.

No room? Put it in the dingy hanging up there, it will fit nicely.

[wingssail]

Originally Posted by a64pilot

...what’s your back up plan? Better have a Honda on board...

There was a guy here last year with a Honda 150 motorcycle sitting on the aft deck of his 47' Hylas center cockpit. He had a very nice generator on it. No belts, no regulator, perfect.

Damn, I can't do any more of this, I've got to get to work.

[Cdn]

The Valeo 125Amp alternator that comes with the 4JH57 produces 90amps at idle. Adding the factory dual alternator kit with another Valeo 125Amp alternator located on the opposite side of the engine will give me realistically 180 amps at 1250rpm while putting a load on the engine and balance on both side to reduce side loading issues.

I will buy the Balmar smart chips allowing these to be externally regulated.

Cheers

N

[noelex 77]

Originally Posted by a64pilot

Several issues, first Nolex keeps saying generators are unreliable

This has just been my experience. Cruising sailors waiting in port for marine generator repairs are not unusual. Your solution of a cheap petrol generator has advantages. If it breaks, throw it away and buy another.

Main diesel engines also need attention, but boat owners can repair and service many problems themselves and if stuck any mechanic can work on a yacht marine propulsion engine especially if it is a basic non common rail engine. The parts are typically easy and quick to obtain.

Marine generators have more specific parts and the combination of diesel engine and electronics leaves third world mechanics out of their depth. There are often multiple protection devices such as an automatic shut off with low oil pressure or poor cooling water flow. While desirable for autonomous operation these systems cause problems in a marine environment. This is often further complicated by restricted access. Generators are frequently tucked into smaller spaces. Marine generators need to run at a specific rpm to achieve a stable alternating wave form. As well as the generator itself there are multiple systems such as battery chargers and electrical switching that needs to function correctly for the system as a whole to work. There is a lot that can go wrong.

In any case the main engine is essential (although there are some rare and very brave/hardy souls who would disagree ) whereas a generator is optional. Any associated generator hassles are self inflicted .

In short, the long term reliability of marine generators is not great in my experience. If you can do without the complication this is a worthwhile goal, but the compromises involved with the alternatives are not for everyone.

Originally Posted by a64pilot

The Triskel is a single point of failure, and would seem to have some complex electronic controls.

To be clear, I am not a great fan of the Triskel system. Personally I think a simpler solution is superior, but the Triskel (and similar systems) provide alternatives that have not previously been available so they deserve some consideration and evaluation.

There is no perfect answer to marine power generation, only alternatives with different compromises.

[Dockhead]

Originally Posted by noelex 77

This has just been my experience. Cruising sailors waiting in port for marine generator repairs are not unusual. Your solution of a cheap petrol generator has advantages. If it breaks, throw it away and buy another.

Main diesel engines also need attention, but boat owners can repair and service many problems themselves and if stuck any mechanic can work on a yacht marine propulsion engine especially if it is a basic non common rail engine. The parts are typically easy and quick to obtain.

Marine generators have more specific parts and the combination of diesel engine and electronics leaves third world mechanics out of their depth. There are often multiple protection devices such as an automatic shut off with low oil pressure or poor cooling water flow. While desirable, these automated systems cause problems in a marine environment. This is further complicated by often restricted access. Generators are frequently tucked into smaller spaces. As well as the generator itself there are multiple systems such as battery chargers and electrical switching that needs to function correctly for the system as a whole to work.

In short, the long term reliability of marine generators is not great in my experience. If you can do without the complication this is a worthwhile goal, but the compromises involved with the alternatives are not for everyone.

In any case, and without the slightest doubt, any marine genset is less reliable and more difficult to repair than an alternator.


But among marine gensets there is a huge range of reliability. Simple, and heavy, is better. The worst are the horrendous Rube Goldberg style Fischer Panda and similar. The best are Northern Lights and similar simple, heavy, heavy duty, prime power rated generators.



Just one data point, my heavy duty 1500 RPM Kohler has never failed me in 10 years and thousands of hours of work. And it was already 8 years old when I acquired the boat, so presently 18 years old. Similar reliability indeed to a propulsion engine. The only issues I've had have been related to heat exchanger (due to my own stupid failure to change anodes) and air leaks in the fuel system (external to the genset). Gensets like this can be relied upon.

[a64pilot]

My generator isn’t expensive, but it’s a built in Diesel. Spares are inexpensive and easy to source, unless of course it completely packs it in.
99% of “Cruisers” and honestly especially that kind that cruise from marina to marina and run a generator to keep the AC going in between, don’t have the knowledge or the desire to maintain a generator, they aren’t frankly the type to get their hands dirty.
They didn’t mow their own grass, nor maintain their automobile, why should they their boat?

You run into that that type often, I overheard two taking the other day, one saying that they just couldn’t sleep at anchor. I told them not to worry when they got some experience they would sleep soundly. Well she gave me a disgusted look and said we just got through doing the whole loop, and we only anchored twice, I can’t understand why people want to live like that.
Well I can ensure you those two nights the generator ran the whole time, and I can also ensure you that when they remember to change the oil, they call someone, and if someone isn’t available they just go on, and keep putting hours on the same oil.
I do carry a Honda also, because well it’s 47 lbs and $1,000, why not?
Really the Honda has a lot going for it, the exact same thing that has you using the two portables for a fridge and freezer works for the Honda too.
Just it busts a gut trying to run an Air Conditioner, not that I do often when cruising, just one night last year, but it was Africa hot and no wind that night on the ICW.

Most Cruisers don’t understand batteries at all, every day on the net in Georgetown someone was asking to borrow a battery tester, because there must be something wrong with theirs. I mean every day, and it was different people too, not the same guy.

It can’t be that it’s not charged they run the motor an hour every morning.

[wingssail]

Originally Posted by a64pilot

My generator isn’t expensive, but it’s a built in Diesel. Spares are inexpensive and easy to source, unless of course it completely packs it in.
99% of “Cruisers” and honestly especially that kind that cruise from marina to marina and run a generator to keep the AC going in between, don’t have the knowledge or the desire to maintain a generator, they aren’t frankly the type to get their hands dirty.
They didn’t mow their own grass, nor maintain their automobile, why should they their boat?

You run into that that type often, I overheard two taking the other day, one saying that they just couldn’t sleep at anchor. I told them not to worry when they got some experience they would sleep soundly. Well she gave me a disgusted look and said we just got through doing the whole loop, and we only anchored twice, I can’t understand why people want to live like that.
Well I can ensure you those two nights the generator ran the whole time, and I can also ensure you that when they remember to change the oil, they call someone, and if someone isn’t available they just go on, and keep putting hours on the same oil.
I do carry a Honda also, because well it’s 47 lbs and $1,000, why not?
Really the Honda has a lot going for it, the exact same thing that has you using the two portables for a fridge and freezer works for the Honda too.
Just it busts a gut trying to run an Air Conditioner, not that I do often when cruising, just one night last year, but it was Africa hot and no wind that night on the ICW.

Most Cruisers don’t understand batteries at all, every day on the net in Georgetown someone was asking to borrow a battery tester, because there must be something wrong with theirs. I mean every day, and it was different people too, not the same guy.

It can’t be that it’s not charged they run the motor an hour every morning.

A64, Cruising has gotten too easy. When people had to navigate by sextant it took a little skill and dedication go cruising. Now anyone with some money can do it, if not well.

And suffer some inconvenience? Why would they, they didn't at home.

But they often find that cruising is not to their liking. The boat is used less and less each year (grandchildren and Norstrom sales are common excuses) and soon the boat is for sale. We see the same boats recycled every few years.