Readers of my previous post on the subject will be aware that we try to generate as much power as possible via renewable resources – wind and solar. This is driven by a desire to keep the boat as simple as possible, and to avoid the need to run our engine at rest for charging – a real no-no for us.
So far our mixture of solar (180W full time + 85W in harbour) and a Superwind 350W wind turbine has done us proud. Even at higher northern latitudes when one source is not effective, generally the other takes up the slack. The solar panels especially have been a revelation, silent and highly efficient.
But the wind generator has been something of a conundrum. Well made, excellent power output above 10 knots of breeze, no vibration (unlike some others I’ve tried) but nobody could pretend it was the quietest unit. Not so much in steady winds, but when accelerating or decelerating it made an infernal ‘whipping’ noise, which made us want to turn it off except in stronger winds – defeating the object of having it.
So when we heard that Superwind had developed a new ‘silent’ blade we thought it had to be worth a try. The website spoke of ‘a reduction in noise emissions of 50% (10db), achieved through aerodynamic structures on the blades similar to sharkskin, which induce micro turbulence to improve aerodynamic and acoustic performance’. Hmmm, I thought.
Straight out of the box the blades looked to be identical with the originals, apart from the aforementioned ‘aerodynamic structures’, which actually appear to be little more than a row of raised V shaped mouldings pointing towards the leading edge of the blade. My inner cynic began to work overtime, and the icy thought of the possibility of yet more wasted money began to chill my Scottish heart.
But paid for they were, so up I went and fitted them. The next day dawned breezy, so we hit the on switch. And the result? Amazing – you simply wouldn’t believe it’s the same machine. No whipping noises at all, and the overall sound levels are definitely down. No scientific measurement here I’m afraid, but the difference is remarkable, and I’d have to accept that the figures quoted must be about right, certainly on our machine – fair enough, and all credit to Superwind for producing something that ‘does what it says on the tin’.
In the past we’ve had to shut the turbine down on occasion. At anchor, for example, when other boats were near, or when nerves were already jangling during a tricky manoeuvre (switch it off, and the wind automatically goes down two wind strengths), but I doubt we’ll ever have to do that again. It is now so quiet that the ambient wind noise from rig and fixed structures would make as much noise, and so mask any sound the turbine generates.
Which is great news, because there’s no point in having a wind turbine that you can’t bear to use, and we’re looking forward to more ‘free’ power as a result. And whilst we still reckon that the solar panels deliver more bangs per buck, the new silent blades will help to rebalance that equation more towards the wind turbine. The cost wasn’t cheap (around £180), and we wish these blades had been fitted when we bought the unit, but the cost has to be worth it in the long term. And all new Superwind units now have the silent blades fitted, which should undoubtedly remove what was a powerful obstacle in terms of sales appeal.
So – peace at last!
Have you made a comparison with the Rutland 913.. ie. in terms of output and noise?
Exciting report. The Air Marine we had on Danza was so noisy the we had to shut it down for peace in the anchorage or even peace within the family. I did not even reinstall it during the current refit. Thanks for your food for thought.
We had the Rutland 910 on our last boat, and it was very quiet, but the power output was totally different. The Rutland gave a small steady charge from low wind speeds, ideal for leaving on when off the boat, whereas the Superwind can provide a major boost. The 913 is a better unit than the one we had, but I’d still suggest the power output would be far less than the Superwind.
I’d say that the Air Marine was noisier than the Superwind before the new blades, but now would be far louder. Interestingly, the really offensive noise from both units (the whipping sound) was similar in both 3 bladed machines. The fact that it can be cured for one suggests to me that the same could be achieved with the Air Marine – which would please a lot of people…..
Interesting comment on noise—we used an Air Marine but we even had neighbouring yachts complain of the noise! We unfortunately also had a terrible problem with their internal regulator, the first failing a month out of warrantee, then waiting all summer for a replacement and that failing again after 15 months, on passage to Greenland so again no back up power for the summer. We bought a diesel generator!
Recently bought one of the quite simple KISS high output generators. The unit has proven to be all they say and very quiet. 5 – 7 amps at 15kts and all but 10 amps at 20kts. The power curve builds from there. The electric brake works well up to 30kts. This is simply a reversal of one of the field windings making the fields fight one another, and so cease to rotate. At higher wind speeds they suggest securing the blades as there is a rapid increase of revs that could be damaging. Well worth a consideration, and ‘does all it says on the box’ + repairable anywhere in the world.
Hi Andrew, This seems to be a common theme with the Air Marine, which is a pity, as on the face of it they are a light powerful unit. In my view, unless a wind generator is (a) powerful, (b) quiet and (c) reliable, it’s more trouble than it’s worth, as your comments bear out.
Thanks for the update on the KISS, David – we looked at these when we built the boat, and they looked good – powerful and with the advantage of using off the shelf components. But we had difficulties communicating with the factory at the time, and so went for a European unit that was available instantly. Good point re being able to shut down these generators – our old unit had to be manually turned away from the wind and then tied off in big winds – never my favourite moment. But from your experience the KISS would meet all of my criteria above, which is good news. When these units work well they are of real benefit.
We like our KISS, but find it has to be turned away from the wind in over about 25 knots. Noise level is low, and not an annoying pitch. At 20 knots +, we turn it partially away from the wind to reduce effective wind speed, then it generates 10-20 amps. Once stopped, the electric brake holds it fine, but it will not stop a screaming runaway, because the thermistors in the windings are open. If not stopped, the noise at 35 knots is incredible. We have had ours screaming for a day at 45 knots (no damage) before we learned how to tie it off safely.
On our last boat we had a Rutland 910, and the thing I liked least about it was stopping it in strong winds, largely because I got nicked on the shoulder by one of the blades when trying to turn it away from the wind in a gale.
You couldn’t leave it running in those conditions due to the noise and the nervousness it engendered in anyone near it! So for me, the ability to shut it down via a switch from below is a must. It’s a pity that your KISS can’t be shut down in that way in very strong winds, as stopping it manually is not an activity I’d care to return to.
Hi Colin, do you want to sell the original blades as my land based Superwind is in a remote location and I bought it incomplete and need a blade set. Cheers Steve
I like this Superwind turbine for one reason: It can be easily installed on boats. Its small, practical and reliable. My cousin tested one and he is very satisfied. I have also posted something about it on my blog WindOption.
I am trying to contact KISS factory, since March 28 Th, already send them 4 e-mail, plus an order without the 8 visa card number propousitly, to force them to contact me.
Until today nothing happen, so I believe they are not interested on sales.
My decision go on way to buy a Silent,produces a little less power, but what realy I would like is the KISS
Sad to relate, but I had the same problem with them in 2008, so it seems nothing has changed. What a pity as it looks like a really good unit.
Hope the Silent proves a good choice – good luck.
There is another solution. A company called Kronos has been manufacturing large VERTICAL axis wind turbines for the midwest farmers, which have proven to be absolutely SILENT in operation, and with good output curves using rare earth magnets (neomodium). They have just come up with a new design for sailing yachts, made to attach to either side of the mast (a pair), preferrably the mizzen, to be used underway too. This was debuted at the Miami Boat Show a few weeks ago, and I ordered one, scheduled delivery next week. The other interesting comment is that they do not require shutting down in a squall or sustained high winds, as their geometry creates a vortex at 35 MPH that prohibits the wind from pushing it any faster. Such an attribute is a must on a large diameter farmers turbine which is permanently mounted. This is the biggest advance in wind generation since the Windbugger was introduced 30 years ago. I’ll post installation photos and performance comments when it is installed.
Any word on your Kronos install? I’m really interested to know how it went and what you think of the system. Please email me directly at gregmac78(at)gmail.
Just by luck I contact the USA dealer, and has been informed that they stop productin several monthes ago, and will return to productin now, but still got quit a few orders to delievery.
I don´t got a single ideia when I could have mine, so I hope silent will do the job
Best contact is John Gambill at Hotwire in Tarpon Springs, Florida.
+1 (727) 943-0424
I tried the phone (at 0900 sunday) and got voicemail, so at least the line is alive
We have had excellent service and tech support from John
Our Kiss is running fine after 5 years of about 6 months/ year full time cruising
Anyone here have info on the Airmaax? Quiet, well-built, and expensive. Some good comments on other sites.
Is any one can tell me about the D400 compaire to the superwind 350. Thanks.