Wind Generator

[Dockhead]

I expect that I will be on a mid-river mooring again from April. That means no shore power.

I ruined my 8 service batteries this year because I failed to appreciate that you must have some form of trickle charging if your boat lives off shore power. My bad.

I am going to replace all of the batteries soon and I am anxious to avoid repeating. I think I need a wind generator. The question is what type and size.

My purpose in installing the wind generator is not to produce my entire or even a large part of my power budget. I have an excellent generator (Kohler 6.5kW heavy duty low speed) plus massive (110 amps * 24v) secondary alternator on the main engine, and don't suffer from power shortfalls in general. In fact, I was cruising for more than a month this summer with the ruined batteries, and even like that we didn't have any huge problem with power -- just had to run the generator a little more often.

So my eye falls on the Rutland 914 which is economical and is supposed to be extremely quiet. I know it won't produce enough power to run a 54' boat, but for me the purpose of the wind gennie is to trickle charge the batteries while I'm not on board.

My question is this -- will the Rutland produce too little power to even trickle charge a large battery bank of 440aH x 24v nominal (like an 880aH bank on a 12v system)? I imagine that there is a minimum power level required to get any charging process started at all? You could not, for example, I am quite sure, take a 5 watt solar panel and hook it up to my bank and get any result, even with totally isolated batteries and zero load. Not so?

So what sayeth thee all?

[boatman61]

I quite like these..
You'll have to do the math to see if they're for you but like the lack of blades...

The latest addition to the range is the FORGEN NT model. Designed in conjunction with the Faculty of Engineering at Bristol University the NT produces 50% more output for only a small extra cost. Key design features include:

• Maximum output of 18 watts @ 15mph average wind speed over 24 hours.
• Redesigned 8 pole alternator using rare earth magnets.
• Improved coil design.
• Weight of magnets reduced allowing rotor rpm to increase by 15%.
• Higher rotor speed enables peak output to be reached more quickly.

The FORGEN NT wind generator is a vertical axis design able to operate in low wind speeds but also able to withstand extremely high wind speeds up to 175 kts. The FORGEN NT design offers the user several important features, for example:

• Precision balanced rotor allows maximum advantage to be taken of low wind speeds.
• Safe and silent in operation. Will not annoy your neighbours.
• Easy to fit to masts or rails. Fittings available for mounting on buildings.
• Compact. Mounts close to walls or masts. The fixed rotor catches the wind from any direction. No need for oscillating blades.
• No regulator required. Can be connected directly to a battery of suitable size. The circuit senses the resistance change in a fully charged battery and automatically responds.
• Designed for 12 volt application but can also be used with 6 volt or 24 volt batteries. The FORGEN NT will produce twice as many amps with a 6 volt battery and half as many amps with a 24 volt battery.
• Safe non-blade design. No risk of blade fracture in high winds.
• No twisting of connecting cable.
• No maintenance required.Fitted with sealed bearings and corrosion resistant components.
• Height 370mm. Rotor dia. 150mm.
• Angle bracket mounting included in list price.
• 10m. cable fitted as standard.

No affiliations... just think its neat...

[Dockhead]

I've seen those, and also think they're very cool. But 18 watts?! That's like 0.8 amps at 24v. 0.1 amp per battery. Surely that will do precisely bugger-all for my battery bank, not so?

[boatman61]

ROFL.... I said the math was 4 you... I'm crap at tech..
I HAVE to sail simple...
and I still think they're neat.. (tidy)

[medicrene]

Hello,

If a trickle charge is truly what you need, then even a small charge will do. As for a solar panel, unless it is a 24 volt panel, it will not do a thing. On the other hand if you hvae two 12 volt panels (even 5 watts each) you will get a trickle chage that keeps batteries fresh, but will do nothing more.

If you are going to buy a wind generator and take the time and money to install it, why not put a little more money in the pot and get more powerful wind generator? Someday that Genset may not work.

The Witchdoctor

[SteveT]

I've got a Rutland 914 and for my minimalist bells & whistles (380 Ah battery bank) approach it works fine PROVIDED there is enough wind. It is hard to believe but even in the UK during the summer there can be longish periods where there is not much wind. Through the winter it is great, we use no shore power at all, but in the summer not always. I'd guess a lot depends on how exposed your mooring is etc. On the quietness side it is excellent, I can't hear it all although the boss says she can if within a few metres.

[Bash]

They make a 24v version of the new 914i, and I think it's the perfect generator for your needs.

I don't think you're doing yourself any favors by running that large a bank, especially on a boat that spends its summers on a mooring. With a diesel generator and a wind generator working together, you may find that a smaller bank serves you better.

[Badsanta]

replace one for a start battery and get a small solar panel. replace the rest when you plan to sail more.

[Dockhead]

Follow up:

I had a Rutland 914i installed by the electrical wizard of Cowes, and have been using it for about a month now.

It produces remarkably little power -- much less than I expected. Vastly less. It's been blowing a hoolie the last two days with winds at my mooring often over 30 knots and rarely under 20, yet the Rutland has only produced about 1 amp/hour per hour -- so 25 watts on average. Barely enough to run an anchor light. I have watched the regulator during 30-odd knot gusts and have never seen more than 90 watts indicated, and that for the briefest moments. It's supposed to produce 140 watts at 11 m/s. Not by my measurements, not even close.

I guess it might make up for self-discharge of the batteries and maybe run the bilge pump, when I'm away from the boat, but doesn't seem like it can pratically do much more than that

[Pete7]

DH, thanks for the follow up. Think that puts the final nail in the coffin for me, wind is out.

Interestingly I bought another 80w solar panel yesterday off e bay. I am hoping that this and the exiting panel will be enough that even if it doesn't keep the batts topped up then support us for at least 5 days in harbour before we need to run the engine to top them up.

Pete

[Celestialsailor]

Originally Posted by Dockhead

Follow up:

I had a Rutland 914i installed by the electrical wizard of Cowes, and have been using it for about a month now.

It produces remarkably little power -- much less than I expected. Vastly less. It's been blowing a hoolie the last two days with winds at my mooring often over 30 knots and rarely under 20, yet the Rutland has only produced about 1 amp/hour per hour -- so 25 watts on average. Barely enough to run an anchor light. I have watched the regulator during 30-odd knot gusts and have never seen more than 90 watts indicated, and that for the briefest moments. It's supposed to produce 140 watts at 11 m/s. Not by my measurements, not even close.

I guess it might make up for self-discharge of the batteries and maybe run the bilge pump, when I'm away from the boat, but doesn't seem like it can pratically do much more than that

Something seems seriously wrong there. It should be putting out much more than that in that kind of wind. Is is connected to a regulator? If so, what voltage is going into it from the generator?

[sailorboy1]

Seems a LOT different than some other reviews on the thread,

[Dockhead]

Originally Posted by Celestialsailor

Something seems seriously wrong there. It should be putting out much more than that in that kind of wind. Is is connected to a regulator? If so, what voltage is going into it from the generator?

I didn't scrimp on the regulator -- it is Rutland's own digital HRDi regulator with MPPT.

[Dockhead]

Originally Posted by Pete7

DH, thanks for the follow up. Think that puts the final nail in the coffin for me, wind is out.

Interestingly I bought another 80w solar panel yesterday off e bay. I am hoping that this and the exiting panel will be enough that even if it doesn't keep the batts topped up then support us for at least 5 days in harbour before we need to run the engine to top them up.

Pete

I remember well that you advised me to go with solar, when I was thinking about it. Next time I'll listen to you!

[Celestialsailor]

In an average wind speed of 10.9 knots, the Rutland 913, tested by Practical Sailor, produced a two day average of 38Ah. I would check the open voltage coming out of it without the regulator. Is it rectified Dc coming out of it, or does the ragulator change it to DC?