What about those Whispergens ??

[Bill Highet]

Sorry if you feel that you've been mislead in any way Alan. We definitely see ourselves as being in the micro combined heat and power (mCHP) business as opposed to the stand-alone generator business and we don't try to sell people an mCHP system when a stand-alone system appears to better suit their requirements.

I note also that there have been some negative comments here about us not promoting our product via the website. Please be assured we are not hiding but we did read the instructions when we registered and we do not wish to break the rules.

Gary continues to log every enquiry received by us and every one is responded to by the most appropriate technical person. There are the occasional bouncebacks that we can't do much about but we are obviously pleased to receive the enquiries.

I will ask one of our engineers to review the various technical questions raised on this site and provide a response ASAP.

Regards

Bill (Whisper Tech)

[Lindsay]

Hi to all cruisers interested in the WhisperGen. I am one the product support team engineers and Bill has asked me to briefly reply to some of your questions regarding the mechanical and technical aspects of the Stirling Cycle principle behind the machine and to clarify some of the misconceptions and false assumptions that have sprung up over the last few weeks on the forum. I can’t promise to cover all of these but I ask that if you find I have missed anything or have not explained something adequately then to please let me know and I will try and provide an answer on a follow up reply.
The WhisperGen was first conceived back in 1987 as a PHD thesis project by Dr Don Clucas at the University of Canterbury in Christchurch, New Zealand. As a long time devotee of the Stirling cycle principle Dr Clucas was interested in a possible commercial application for it, something that had been tried many times in the past right back to 1815 when the Rev Robert Stirling, a mechanically inclined Scottish vicar, successfully ran his first engine. Dr Clucas’ and his associate Dr J K Raines’ paper outlining the Development of a hermetically sealed Stirling engine battery charger can be read in its entirety on the Whisper Tech website. http://www.whispergen.com/content/li...evelopment.pdf

The Stirling engine operates on the basic principle that heated gas expands and cooled gas contracts. This expansion and contraction within a cylinder will force a piston to move in and out, which can be harnessed to a transmission and alternator to generate useful power. In its simplest form pistons move a working gas (eg, nitrogen) through hot and cold heat exchangers. The WhisperGen design uses four pistons in a square pattern with each at 90o phasing. In the marine version the burner is diesel fired and the continuous firing provides a cylinder head temperature of approximately 900C or 1600F while the water cooled bottom end of the cylinder is cooled to around 60-70C or 140-160F. The large difference of upper and lower cylinder temperatures provides significant potential for power output which is transmitted via a patented ‘Wobble Yoke’ device to an alternator. The water used to cool the lower end is cycled around the Primary coolant circuit through an Exhaust heat exchanger which transfers heat from the burner exhaust into the primary circuit. The resultant exhaust gas temperature exiting the outlet pipe is reduced from 430-450C to 60-70C. This cool, relatively dry exhaust obviates the need for auxiliary water cooling which in turn means no gurgling or splashing noises from the hull outlet.
Battery charging current is produced by the alternator which is rectified to 12 or 24v. The integrated electronics module or MPU provides an automatic charging regime using current shunts which measure the ingoing and outgoing current from the battery bank. At a preset level of capacity the WG will start, bulk charge, absorb charge and when a “tail current” value is reached will shut down and stand by until the next cycle. I note that Jack (Euro cruiser) advocates a bulk charge to only 80-85% per cent to increase battery service life and says that he can discharge down to 50%. The comment I would make here is that he must have a giant size battery bank that could well be over specified for his application. The voltage drop at 50% with a smaller bank could mean invertors dropping out and essential DC equipment malfunctioning. (The WhisperGen tail current limit is set to around 7% of the battery size so, in a typical bank of say 500Ah, at -35Ah the WG will consider the Battery charged and shut down). Generally, we have found, the WG system allows the downsizing of a typical battery bank; for a 12V configuration on a yacht of say 50ft, 600-800Ah of batteries are ample (half that size for 24V). The quiet and vibration free operating characteristics of the engine means that it can run for much longer periods than a large, noisy, smelly genset that normally one would want to start, run and shut down in as short a time as possible. This becomes immensely more beneficial and meaningful in those quiet, pristine coral reef moorings at sunset when the merest disturbance can mean the total loss of enjoyment.
In answer to those who question the price comparison of the WG to other gensets on the market; basically it comes down to; why pay so much for a product that produces less power, makes lots of (potentially) waste heat, has a shorter track record than comparable systems and has limited support in the field. The answers can be found in the emails and messages we get from converts; so quiet, batteries always charged, stacks of lovely hot water, normal service takes a few minutes every 4-500hours, no oils or greases, belts, pulleys or filters, no smells and fumes when running. To the detractors of other perceived shortcomings; We acknowledge the lack of global service centres but this is being addressed as we speak. We also acknowledge that, in the past and in certain areas such as Europe, that the service life and reliability of the WG was less than desirable but in our defence, we must point out that like any high tech and relatively complex machine correct and high quality installation is of paramount importance and in this our European experience was remiss. This has been proven by, in the US, Australasian and northern European markets, where installation was performed mainly by factory trained staff, WhisperGens have been running almost without exception, reliably and within design specified life span and performance parameters. Life span before major overhaul is needed, by the way, is around 4-5000hours. (We envisage a like for like, exchanged, factory refurbished core engine at that time to cost around $1500-2500US, there is very little of the componentry that requires total replacement, mainly some off the shelf bearings and Teflon seal rings)
The European installations that were suspect have been largely rectified by having a service guy from the NZ stationed there for several months and further by now having a trained local engineer check, rectify and, in some cases, swap bad engines for new at no expense to the owner.
We have many anecdotal accounts of happy WG owners sailing the high seas with their DC systems in perfect harmony. The “DC concept” is rather a challenge to those who cannot or refuse to acknowledge its merits. The DC WhisperGen has been commercially available now for some 7 years or so and has built up a devoted following in that time and, along with its close cousin, the AC gas powered version for domestic heating and electrical load sharing via the national grid, has been the focus for further development of several large energy players to the tune of $30-40 million US. Something must be good!

[Lindsay]

By the way, if any cruiser wants to email any further enquiries (or order a new WG!) feel free; lindsay.mann@whisperGen.com

[Alan Wheeler]

Lindsay, thank you so much for your reply. It was very informative. One question I have is, what was incorrect about the way the WG had been fitted in Europe? Which brings me to question 1a: how does the WG handle the tilt from verticle it will encounter when a yacht is heeled over?
Thanks

[Lindsay]

Hi Alan
The installation issues we encounted in Europe were many and varied; for various reasons we feel it is inappropriate to discuss them on this forum. Sufice to say that if the manual we provided was followed diligently there would have been a much better outcome. Main problems were; fuel and coolant flow, inferior ancillary equipment and plain, bad workmanship.
As to the angle of heel in a monohull, while we haven't actually tested the theory, it is entirely possible that the WG will operate perfectly ok at any angle, including upside down! The only thing that may be a limiting factor is the flow of fuel through the evaporator. We have a nominal limit of 45 degrees but this is entirely an arbitary value.
By the way Cruisers if you have trouble emailing me, the reason is I typed the address incorrectly! Try this: lindsay.mann@whispergen.com

[Euro Cruiser]

First, I think Lindsay (and by extension, Whispergen) should be hugely thanked for the thorough technical comments in that post. Just excellent overview info and the kind of info that, in the future, probably should be volunteered sooner with references to the on-line pubs made secondarily. Excellent job, Lindsay.

Second, I'd promised to offer the group some follow-up after being provided with a local referral here on England's coast. After researching Whispergen and gaining a better understanding, it's clear to me that this product really is more suitable to seasonal climates where bountiful supplies of hot water, cold injection temps, and cabin heating are primarily considerations of the buyer. Quite the opposite of these things, we're moving from a cold to several warm/tropical climates and so there is simply a mismatch between the Whispergen product as intended and our plans; that's certainly not a negative comment about Whispergen.

Third, I'd like to follow-up on one of Lindsay's comments, since it relates to an earlier post I made - just for the sake of thread continuity/accuracy. The point I'd made earlier is that cruising sailors, who must at times work with limited quantities of fuel and funds, usually find that a house bank (battery) charging regimen that works best within the confines of most battery chemistries, is to charge using the bulk rate up to the Acceptance level (usually around 80-85% of total capacity) and then draw off the bank down to roughly the 50% level. This seems to be the best compromise between battery cycle life (especially harmed by draw-downs below 50%), fuel consumption (since once Acceptance is reached, by definition each add'l minute of charging is using the same amount of fuel for incrementally less and less charging rate), and equipment operational lifespan (before regular maintenance and eventually lifespan reburfishment in required). Our battery bank is very representative of 10-13M cruising boats at 450 amp/hrs, in my experience, and there are none of the compatibility or systems performance issues - as experienced by us or reported by other boats - that Lindsay suggests might or probably would occur. (Lindsay may be picturing much larger inverter loading to supply house services but if that's going to be the case, then the battery bank would need to be far larger).

A Whispergen unit is not going to be the universal answer to energy generation aboard cruising boats. It does seem to be a reasonable, practical solution to the mix of heating and power generation needs many N European boats have, and I suspect it's only New Zealand's distance from here that makes it slower to penetrate the market. I can assure Lindsay & colleagues that, if those with whom I've talked who rely on water-borne diesel-fired heating systems is any indication, you have a market ready for you to capture. You'll put out of business a lot of technicians who are busy doing service calls and repairing units.

Best to all,

Jack
WHOOSH, lying Plymouth, England

[ssullivan]

Hi Lindsay,

Thank you so much for the thorough description of the WhisperGen, addressing our concerns. I think this product makes perfect sense, and is the ideal solution. Unfortunately, I am just slightly outside your market at this time since I don't have the funds to purchase one. I was the original poster and thought this was the way to go. It still might be if I can make a financial case regarding fuel consumption, power output, and maintenance over 10 years.

Thank you again for the great reply. It is very helpful.

[GordMay]

FWIW:
From Stuart Miller, Sydney Harbour, Australia as posted at SailboatOwners.com (‘Ask all sailors”):

Whispergen

We installed a Whispergen DC generator 2 years ago and it is the best bit of equipment on our Beneteau 461. It is a New Zealand developed and manufactured unit and uses an external combustion process, running on diesel (().5 litre per hour), output about 750 to 800 watts, very little noise or vibration (much less than a fridge compressor), and the excess heat is used for water heating and space heating (if needed). We have 600 AmpHrs battery storage and when cruising we run the Whispergen for a about 3 hours every 2 or 3 days. Google will find the web site. The external combustion technology is based on the old Stirling cycle with a very neat way of converting this to rotary motion to drive the generator. No oil, no fumes and low maintenace. And, I am not an agent and have no interest in the company. Just a fan.

[Vasco]

Was looking for something to back up the Kiss wind generator. Settled on Honda EU2000i and then ran acros this thread. Boy, I thought I was onto something until I found out the price - 13,000 USD! And that's just for the unit, not installed. You can get a reliable, tested over the years, conventional generator installed for less than that. It is encouraging though that the manufacturer engaged in this dialogue.

[RonaldL]

Having studied the WG in detail fort he past 2 years, because I was interested in buying and using it in my sailing boat, I did not opt for the unit in the end. But this was mainly for the reasons mentioned in this discussion before: bad experiences in Europe. In the past years the Dutch agent for WG did a very bad job with the result that NO unit on boats was working properly. This has improved since the New Zealand technicians themselves has worked here in Holland and NOW the units seems to operate OK. That's surely a relief for the sailors in question.

Still there are some major topics with this engine (and maybe the manufacturer should address to this in a reply?):
- the unit is silent, however not when it starts: a relatively loud noise comes out of the exhaust during a couple of minutes (during initial start-up heating of the evapotor). This has forced some sailors to prohibit the unit to start during the night when neighbours are sleeping. Maybe this should be remedied by installing some kind of noise damper.
- the exhaust system is critical. no water is allowed to back flow, no backpressure in the exhaust is allowed. you cannot just simply layout any exhaust configuration: when not right, it won't function.
- one should not have a vacuum (underpressure) in the room where the WG is placed, otherwise the exhaust will not function.
- already stated in this topic: when not using heat, so only making electricity, the efficiency of the unit is poor.
- the stated 6 kW of heat produced is at 60 °C. Generally speaking central heating systems in Europe (or rather Holland) are based on 90/70 °C, that means 90 °C from the boiler to the convectors and 70 °C return from the convectors back to the boiler. Now with this only 60 °C watertemperature the effectiveness of the central heating system will be much less. And the size of the convectors or radiators should than be much bigger to get the same heat into the air of the living room. The WG can however be set to a higher temperature, max. 70 °C. But nobody specifies what power is than achieved, it must be less than 6 kW. And even 70 °C is not so very high for heating purposes. At these low water temperatures one would be forced even to use fan driven air-heaters to increase the speed of warming up the boat's interior or even to be able al together to extract this 6 kW from the water and put in in the air of the living room.
- this rather low water temperature also affects the heating ability of a possibly intended hot water boiler for drinking water. For keeping the system legionella free (veteran desease) the temperature of the boilerwater should be above 65 °C. Even when the WG supplied water is at 70 °C it will be hard to get the drinking water in the boiler to reach this 65 °C. So maybe one wants to heat the boiler with additional electrical heat from batteries (filled up by the WG). However than something strange will happen. The boiler temperature will than be higher than the WG water temperature, so the WG water is heated to above 70 °C. That is not to the liking of the control circuitry of the WG and it will try to dump this extra heat into the ocean trough the secondairy cooling system. This is getting complicated.
- maybe bacause of different gasoil specifications al around the globe, in Holland there was a lot of fouling of the evaporator causing the WG to malfunction. The evaporator had than to be exchanged and cleaned every 100 -200 hours. Far from the specified running time of 2000 hours. I do not know if this has been improved lately.

One of the WG installed in a dutch boat is traveling around the atlantic at the present moment. I would be interested to hear from them if and when they return from their voyage. If something's worth wile, I'll put it up here.

[Lindsay]

Ronald raises some very valid questions and it is timely that we address them as the experiences we had in Holland with the factory technicians visiting a great many WhisperGen installations highlighted some of the issues that were causing owner frustration unbeknown to us.
The noise problem on start up is a phenomenon common to high temperature burners. We have now identified the cause of this and have developed a new Evaporator that entirely eliminates this noise, at the same time boosting power levels, and reducing carbon build up. We hope to release these new evaporators when all testing has been completed. We have some units operating in the field on trial and the feedback so far has been encouraging.
The exhaust backpressure is a factor but not as critical as Ronald stresses. The main criteria is the need for condensation drains at low points and to provide the hull outlet with a weather shield to prevent wind and wave action causing a ‘surge’ of air to return down the exhaust. This is also common with any external combustion device. It is a simple matter of following the installation manual, the logic of which seemed to escape some ‘installers’ in the past.
The WhisperGen needs air to operate, as any heat engine does, internal or external combustion. It is not difficult to provide suitable ventilation; all the WG needs is a 50mm2 vent.
In answer to Ronald’s questions re the heating; the DC Marine WhisperGen was designed first and foremost as a battery charger/monitor. The heat produced during charge periods can be used to heat water for storage or for space heating. In other words; as an auxiliary heating device. Some of the early promotional material overstated this and many took it mean that you could run the machine 24/7 for heating. This misses the point and we are quick to point out that it is an expensive machine to use just as a heater. We have now developed a system whereby the WG has its own compact cooling system with a heat exchanger between this system and any heating circuit around the boat. This heating circuit can incorporate an inexpensive diesel fired water heater, excellent brands of which are available, to provide the heat levels that Ronald quite rightly demands; when the WG is running it supplements the main heater. We have installed several of these systems now and the results have been most satisfying to all concerned.
On the evaporator blocking issue we have also identified why that was happening and it turned out to be quite simple. The software controlling the WGs operation has a AI component that senses best exhaust oxygen content on start up. After the initial set up at installation the software program then monitors each start and adjusts the fuel/air ratio ever so slightly to obtain optimum clean burning. That’s great and it works really well, but, after considerable run time the evaporator, for whatever reason; bad fuel, etc, will start to get carbon build up. The software senses this and starts to increase the fuel flow on start up. This lifts the ‘Start Fuel’ value and will continue to do so on each subsequent start until the carbon build up is too great causing flame failure. This was usually happening, on good fuel, at around 1000 hours. So, the owner changes the evaporator and all is well-bit of smoke on start up but not too bad. Now the flame failure occurs at 500 hours. So another evaporator. Failure this time at 200 hours??? What’s going on?? It turns out that if the “Start Fuel” value is not reset to the default, clean start value, then the WG still thinks the evaporator is blocking up and will continue to start with a rich mixture which causes excessive carbon build up, which causes flame failure and so on; a classic ‘loop’ scenario. The software can only ‘up’ the fuel and not reduce it.
We have now issued instructions with all new evaporators to make sure this very simple reset task is carried out.
WhisperGens are still rolling out the door to very happy customers! (When installed correctly)

[ssullivan]

As the starter of this thread, I am quite impressed with WhisperGen's responses. They really seem to be a stand up company. I am really hoping the product ends up selling extremely well... that way I'll be able to afford one.

For now, I went with the standard GenSet due to the cost factor.

Great customer service and follow up though... I'm thoroughly impressed.

[Alan Wheeler]

Darn I forgot. I was at a boat show a few weeks back, and meet up with Alan of wisper gen. A real top bloke. Hey was ery mhelpful and took me through the cut away display unit they had on show. They malso had a demo unit running and I was very impressed with how quite it was. Let me start with that part first. The dB level was very low and it would be hard pressed to hear this running if it was in an engine room or similar. What's more, it is running at a higher frequency than a normal engine exhaust cycle, so it doesn't have the same vibration. It has no detonation so lacks any noise from that part as well. So all in all, it is a very easy noise to put up with.
The engineering was superb. Reliability seems to be very good, however, Alan was honest enough to say that there were still area's they want to improve on still.
The only draw back for me, was the price tag. It's out of my reach, but that ain't saying alot. For most Yachties I have meet, I doubt the price would be of the same issue.

I won't go into how it all works, as Lindsay and Alan have done a very good job of explaining that in the above threads. All I can say, is that they are a Kiwi company that I am proud the say is Kiwi. I hope these guy's do well.
Now--- maybe I should see if they list on the stockmarket

[DeepFrz]

Any news on the WhisperGen? Anyone have personal experience to report?

[Dockhead]

I am necroposting (sorry!) but someone is selling an actual Whispergen in the classifieds, so I dug up this old thread.

I remember at the time discarding the idea of using a Whispergen because of the supposed low efficiency of the electricity generation process if you're not using the heat.

But I just ran the numbers -- 0.5 liters/hour for 800 watts is actually not that bad -- ,625 ml per watt/hour generated.

My very good Kohler genset uses 1.5 liters/hour while producing 50% of its rated output -- that is, 3.2kW. That is about ,47 mil per watt/hour generated -- not an enormous difference.

Besides the 800 watts of electrical power, the WG is supposed to produce 6kW of heat. Well, I can use that heat during about half the year, in this climate.

And when you're not using the heat, you are not producing electrical power in a grossly inefficient way. In fact, it would be in real life probably about equal to my Kohler, because I can't provide a perfect load all the time. Either the load is less because the battery charger has tapered off, or I've added loads artificially like the calorifier for the sake of the health of the genset.

Now I could tap into the fresh water cooling of the Kohler and run my central heating on that. But I'm not going to run the Kohler all night long -- it produces too much power; it's not needed for 8 hours at a time.

The WG, on the other hand, could just perk away all night long, keeping up with the anchor light and central heating pumps and fans load, and putting some charge into my batteries.

Oooh, I like it, after all. As far as I understand they are not made any more, correct? Are they supported any more?