My experience with Whispergen and Futurenergy generators
Saturday, 2008-December-6- 3:29

As I received many inquiries about both of these critical elements, I deceided to post the reply I did to the last emai I received.

Subject - Sujet: wind generator
Message: Hi
We moored at the other side in Nuuk next to the Kisavik of Jess (very nice and helpfull guy and his family), with our 49 ft sloop.
We are also sailing in the actic area for the last two years and will go next summer to Labrador again.
I found your website this week, while we are looking for a wind generator You have the 1kW of futurenergy. On their website is stated that you are very pleased. Ik like to have that confirmed if possible and specially the noise levels. We like to run it especially in low wind situations, which are more common then strong winds, but also it should not have any problems with the strong winds upon till 50 kn when we sail, on a sailboat you cannot take it away then.
Futurenergy states they have a kind of furl system but do not make clear how it works. How does it works.
I am suprised you are using the Sterling engine generator, because I found out that it gives a lot of problems and will not give much electrical power.
Seeing your lovely pictures of snow in Nuuk gave us a little homesick feeling, they are beautifull.
Please do our sincerely greetings to Jess and his lovely family from Herman and Rian.
Regards Herman



thank you for your email. I didn't met Jess yet, but will track him to pass your regards.

Yes, every world they printed is true, the Futurenergy is a great wind generator. Having used some other brand you usually find on sail boat, I can say there is a world of difference. The quality of engineering, the careful construction, the power. But here, we are hitting the main problem of this type of generator for a small boat: it's too powerful.

You have to understand that it is a permanent magnet turbine, which mean it start to produce electricity at very low rpm. It also mean that it produce a lot of power quickly as soon as the wind pick up. This wind turbine will power your boat much more than you was ever dreaming of.

Regular wind turbine need to be hook up to a battery to be excited and start to produce. Just like an engine alternator. BUT Futurenergy is a permanent magnet, which, unless other wind turbine, doesn't need to be connect to a battery to start to be excited. It is always excited. Then you have a problem : as soon as it begin to rotate, you have power. If it is not connected to a battery bank, it will soon loop then burn out the wind turbine itself. In a land based installation, that's not a problem, you add a dump load in your circuit and you are done.

On a boat, that's an other story. In a moderate windy day, you will fill and top up the batteries in a few hours. So what to do with all these extra amps??? You have to burn them whatever. That is why Futurenergy strongly recommend to add a dump load in your circuit and you have to follow this advice.

Be extremely careful with this critical point. A dump load is a resistor which can get very hot (burning red). This is dangerous in a confined space especially when you are not monitoring it.

Onboard Aurora, I bring it down for summer months as the engines are on use. Far way too much energy for what we burn.

It's also true that is is the less noisy wind generator I ever had, with the less vibration, if you take care of a good rubber mount. There is a cost for that: the blades are sharp and don't try to catch them when it rotate. They are truly very dangerous past 10 knts. I believe they could literally cut your hand.

Self furling
This is also true, it work pretty well. I got up to 77 knt while spinning and no problem. The system is quite simple and can't jam. A very clever idea, this is why I said is a extremely well engineered generator The cost of that is minimal: the tail doesn't always fully come back by itself, or only after a long period when the wind direction change, so you may have to help it yourself when the wind calm down.

I insist, it's a wonderful wind generator, the best I ever seen. The power is there.
But it's not yet ready for boat, unless you take great care of the install and customise it. Too big, too powerful, too dangerous. In anyway it should be mounted in a location where no one can be able to put hands in the blades. You have also to find your own way/system to stop it when you want it to stop. I used it as a source of power when the boat was frozen in ice, I don't want to use it when sailing.

I dream this company making a smaller size, let says 500 W model, more adapted for small boat use. When I say 300, I mean real power, not advertising power like some brands which claim 400W and only produce 30W when the wind reach 25 knts. Maybe if they receive many solicitation...

Usual disclaimer apply here: I have no link at all to this company, I ordered the generator through internet and paid full price. I am just very happy to have found a true wind generator, not a toy as we were use to see around the past 20 years.


For my use -cold climate, in need for heat and electricity-, it's a dream machine. I am not a mechanic, I literally hate oil changes, etc.

I loved the fact that it worked 500 hours without any type of maintenance. Not a single one. I never opened the hood for repair since I have it... Just regular checks and pleasure of the eyes, it's a very high tech good looking machine.

It seems that Whispergen problem is more of a commercial problem than any other. The company, Victron Energy from the Netherlands, which was the first importer in Europe, advertised it as a generator. This is false and induced a misconception of the machine which still last. This is a HEATER which produce electricity at the same time. Simple as that. We also have to blame the Whispergen company from New Zealand which doesn't make it that much clear as well.

You have up to 7 kW of heat and 1 constant kW of electricity. On most of the boats they have been install, people dump the 7 kW of heat out of the boat and keep the 1 kW of electricity. But going this way, you end up with a very non-efficient generator. If you want electricity ONLY, you better buy a regular DC generator.

Part of the bad reputation come from installation as well. As people was thinking "generator", they installed it as a generator, taking care of the DC circuit, not of the water circuit. But as any heater, if you don't respect hoses diameters and lengh, curbs, pumps volume, etc. you run into problems, the machine get hot, the alarms start, etc. Electrician are not plumbers and having a heater install by a electrician doesn't do always the trick.

But if you need hot water and heat at the same time, that become a very interesting, high efficiency, close to NO noise, strictly minimal maintenance machine. An expensive toy from and for the 21 century. And don't make any mistake, 1kW constant is the equivalence of a 60A alternator running at full load. That is not negligible.


To conclude, onboard, if everything should fail, solar, wind, diesel stoves, engines, I will want the whispergen and my large bank of batteries to be the last to go. It's an high tech and totally reliable machine. And highly programmable. You can set it up to run a pre-set number of hours per day, leave the boat for a week and come back with a warm boat, hot shower ready and batteries full.

Well, let me touch some wood, there.

I maybe be seen as too enthusiastic. It took me months of hesitations, research, questions, to end up with these machines. I am just very happy not to have made a mistake in choosing them. They are perfectly adapted... to my boat/use, which doesn't mean they are to yours. To resume:



Futurenergy wind generator


Extremely powerful


bulletproof construction and engineering


Not adapted for boat use yet

dangerous if not mounted high enough




A true 21th century engine, minimal maintenance

Silence, feeling of modern confort

program and full detail diagnostic available
High security



The price

Adapted for temperate to cold climate only

Not energy efficient in hot climate


Well Herman, I hope it help.
All the best, Pierre


Article originally appeared on The sailing igloo (
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