Super quiet generator

[Lozzer]

Looking for a night time generator for new yacht. Bigger requirement is low level noise.

Around 7.5-10kw as only maintaining batteries and running forced air system plus occasion other item...

I have looked at Onan, Fischer & Pander plus Whisper.

Want slow revving easy to maintain as his will be for going to be back of beyond and I will be servicing / repairing. Weight is also an issue.

Has anyone installed one of these hybrid systems?

 

[jfm]

The future will be small gas turbines. Discussed quite a bit on my last build thread. I discussed with manufacturers but they are a few years away and too late for your oyster build. You are therefore stuck with current diesel generation if you don't want millions of batteries. You have to have 1500rpm too because that makes the 50hz. You could ask oyster for more sound insulation etc

 

[sarabande]

a development partner in Bladon, to which jfm refers, is Tata. They have some small GT engines in a Jaguar car, so easily generating the KW you require.

They may have some current info for you

http://www.uk.tata.com/media/query.aspx


The MTBF of these units is measured in thousands, if not ten thousands of hours, so servicing is not a major issue. They can also run on a variety of fuels, liquid and gas.


From the USA is an interesting GT, in production, with an output of 29kW. Perhaps a bit big for a genny, unless you wanted it to power the propulsion system via an electric motor ? Three phase - makes sense. They claim 65dbA, which is about the
same as human conversation at 3ft.

http://www.capstoneturbine.com/_docs/datasheets/C30 Liquid Fuel_331032E_lowres.pdf

 

[Lozzer]

That's my conclusion.

Seen some very nice hybrid propulsion systems but I think I might need an engineer degree if I complicate systems to much.

Oyster like Onan as it fits in with their engine supplier thus making spares interchangeable and single service point. I will see if there is a field engineers course on offer as we expect to go some back of beyond places and it would be nice to fix ourselves.

Batteries is another good point, we have a meeting about lithium batts tomorrow. Having replaced our batts on the P85 this spring I'm keen to make sure we get this right. I think the sailing world has a different approach to this area. On the P85 we are expected to run genet 24/7. There wasn't even a 24v water pump until I installed one.

More sound proofing will be the order of the day. Or put it far away from my cabin....

 

[sarabande]

"Batteries is another good point, we have a meeting about lithium batts tomorrow."

Boeing will have a few spare packs sitting on the shelf somewhere


What are the criteria for battery capacity ? 1000s of Ah?

Lithium are great, except where water is involved..... especially sea water. I had to deal not many years ago with a fire in a scrap lorry on the M5 where the Fire Brigade used water to try and put out a fire which had started in a pallet of helicopter Lithium batteries. I'd never seen concrete melt before.

 

[rafiki_]

I think the future may well be Fuel Cells. Mantenance free, silent, etc. smaller versions are used in the armed forces as personal power packs, and as volumes increase, costs will come down.

 

[rustybarge]

The sterling external combustion engine is completely quiet.

Try googling the Philips MP1002CA Stirling generator of 1951, it was a very small sterling genny, but you could build a larger version........

cheaper than than a turbine design and lot quieter.

PS: I was moored behind a narrow barge than was running its genny, but didn't realise this until the owner opened up the engine hatch. He has a 'hospital silencer' installed on the genny. It's a massive dry silencer that silences the exhaust to wisper quiet, and no splashing noise of a water cooler genny. You can find suppliers if you buy a narrow boat magazine.

 

[rubberduck]

We have a Mase, so quiet I had to check it was on when running everything up with all the engine hatches open etc. We can use it overnight & not hear it at all. Only noise from outside is the odd puff puff from the exhaust.

 

[rustybarge]

We have a Mase, so quiet I had to check it was on when running everything up with all the engine hatches open etc. We can use it overnight & not hear it at all. Only noise from outside is the odd puff puff from the exhaust.

Which model do you have?

 

[rubberduck]

Mase IS 8 (I think)

 

[Deleted User YDKXO]

Have a look at Kohler and Northern Lights too. Had Kohlers on my last 4 boats and never had a problem and they're pretty quiet too

 

[jfm]

I had a NL small gen in a brand new boat I chartered 2 yrs ago. About 6 kva. I hated it and wouldn't buy NL at this small size. Kohler and Onan is where it's at IMHO. Lozzer you might want to compare specs for the particular size you want. I chose Onan because at the size I needed it had a shaft driven raw water pump while kohler had belt drive and I let that be the tie breaker in an otherwise score draw. One less thing to maintain

Lozzer with maybe 3 gensets plus a main engine and gearbox you should get a Wasp or Reverso oil change pump to all 5 sumps. Makes maintenance easy. Maybe you had this on p85 so are already used to it

 

[MapisM]

On the P85 we are expected to run genet 24/7. There wasn't even a 24v water pump until I installed one.

Not much to add to what has already been said on your main question, but your comment above made me curious.
Doesn't the P85 have any inverter?
I'm asking because, assuming to have AC always available (at least for low-ish power equipment, and I'd put the water pump among these), I'm not sure to see the point of a 24V DC water pump...

 

[Deleted User YDKXO]

I'm asking because, assuming to have AC always available (at least for low-ish power equipment, and I'd put the water pump among these), I'm not sure to see the point of a 24V DC water pump...

I find it astonishing that Princess did not fit a 24V water pump. Surely sometimes the owner and his guests want total peace with the gennie(s) switched off and in any case the water pump is such a vital piece of equipment that you'd want a back up anyway?

 

[MapisM]

Surely sometimes the owner and his guests want total peace with the gennie(s) switched off

Couldn't agree more, but the same result can be achieved also with an inverter+AC pump, hence my previous Q....

 

[Deleted User YDKXO]

Couldn't agree more, but the same result can be achieved also with an inverter+AC pump, hence my previous Q....

Yup I know but there is an energy loss converting 12V to 240V to power a device which could be powered by 12V or 24V anyway. Anyway I would have thought that on a 85ft boat, the builder would think about redundancy for such an important component. How much would it cost to install a spare 24V water pump for use when the 240V pump or 240V system fails? A few hundred pounds? Failure of the water pump is a ruined holiday or worse for the owner, an aborted charter

 

[MapisM]

I don't disagree with the redundancy principle of course, but the boat size is a factor also in the choice of whether to design the boat systems assuming to always have AC onboard or not.
In fact, in any superyacht, at least the smaller genset is running 24/7, unless connected to shore power.
80 feet or so is possibly a borderline size, and I also would prefer to have the option of not running any genset, while overnighting at anchor.
But personally, whenever given the choice, I'd rather go for an AC than a DC motor, also because with modern inverters the efficiency loss is not much - and possibly compensated by the higher efficiency of AC vs. DC motors, though I'm now just guessing.
In other words, on a boat like the P85, it's not the lack of a DC pump as such which is to blame, but rather the lack (if actually lacking) of a couple of inverters and a second AC pump.
All imho, as always.

 

[Deleted User YDKXO]

In other words, on a boat like the P85, it's not the lack of a DC pump as such which is to blame, but rather the lack (if actually lacking) of a couple of inverters and a second AC pump.

Well I guess Lozzer should tell us why he chose to fit a DC pump then!

 

[npf1]

FWIW, a while back I saw what seemed to me to be a good set up done using Mastervolt equipment. It comprised of a two 1500 RPM gens sync'd with an inverter and power management system. The gen was sized to match the standard run load of the aircon, not the startup load. The additional power at aircon start up or boost was provided by drawing additional AC from the inverter. Seem to recall this approach resulted in smaller/less weight than the traditional approach. It was also very quiet, some of which was achieved using an exhaust system from Halyard.


The reason for the two gens was for running 24/7, so 12 hrs on one, then 12 hours on the other etc.

 

[Deleted User YDKXO]

FWIW, a while back I saw what seemed to me to be a good set up done using Mastervolt equipment. It comprised of a two 1500 RPM gens sync'd with an inverter and power management system. The gen was sized to match the standard run load of the aircon, not the startup load. The additional power at aircon start up or boost was provided by drawing additional AC from the inverter. Seem to recall this approach resulted in smaller/less weight than the traditional approach. It was also very quiet, some of which was achieved using an exhaust system from Halyard.
.

The Mastervolt Quattro operates like that http://www.victronenergy.com/inverters-chargers/quattro/ although it's more designed to supplement a shore power load than a generator load although i can't see why it wouldn't do the latter. I guess if you have a weight or cost or fuel consumption issue, then a gennie + inverter system would work but purely from a noise/vibration point of view, I don't find larger gennies any more intrusive than smaller ones