How Much Real Energy Does Your Wind Turbine Put Out?

[Dockhead]

I installed a Rutland 914i wind turbine about a month ago in order to keep my batteries up on my new pile mooring on the Hamble, which does not have shore power.

I have been surprised at how little practical power it puts out. I'm starting to think that there is something wrong with it.

Last night it blew 21 knots steady all night, with gusts to 30, according to Bramblemet, which is nearby to my mooring. The average wind speed never fell below 20 knots. When I got up, the Rutland had produced only 8 amp-hours of power (at 24 volts) over 8 hours (the HRDI regulator makes those calculations). So an average output of only about 25 watts during a very windy night. The old 913 was supposed to put out 50 watts at 19 knots and fully 140 watts at 21 knots. Something doesn't seem right.

What kind of real life power output do you guys get with your wind generators, Rutland or others?

[Wotname]

Originally Posted by Dockhead

I installed a Rutland 914i wind turbine about a month ago in order to keep my batteries up on my new pile mooring on the Hamble, which does not have shore power.

I have been surprised at how little practical power it puts out. I'm starting to think that there is something wrong with it.

Last night it blew 21 knots steady all night, with gusts to 30, according to Bramblemet, which is nearby to my mooring. The average wind speed never fell below 20 knots. When I got up, the Rutland had produced only 8 amp-hours of power (at 24 volts) over 8 hours (the HRDI regulator makes those calculations). So an average output of only about 25 watts during a very windy night. The old 913 was supposed to put out 50 watts at 19 knots and fully 140 watts at 21 knots. Something doesn't seem right.

What kind of real life power output do you guys get with your wind generators, Rutland or others?

Won't this depend in a great part, what your batteries can accept. For instance, batteries near full SOC and no other loads, then the wind genny can't supply anything except what the batteries will accept.

[Dockhead]

Originally Posted by Wotname

Won't this depend in a great part, what your batteries can accept. For instance, batteries near full SOC and no other loads, then the wind genny can't supply anything except what the batteries will accept.

I thought of that -- but 1 amp is less than the loads even with all the lights off. I never saw juice going into the batteries -- whatever the wind genny was producing was just going to loads, primarily refrigeration. So battery acceptance did not come into play.

The HRDI regulator shows watts produced from moment to moment. I watched it in big gusts over 30 knots and once or twice saw it touch 90 watts (which would be about 3.5 amps I guess), but only for a second.

[Hud3]

Being a curious sort, I looked up the 914i's performance curve on their website.

The 21 knots steady windspeed you mentioned is about 11 m/sec, so according to the specs, the Rutland should have been putting out 9 amps at 12 volts, or 4.5 amps for your 24 volt system. That would add up to 40 Amp hours vs. the 8 AH that your monitor measured.

I'd be unhappy with that, too.
.

[Dockhead]

Originally Posted by Hud3

Being a curious sort, I looked up the 914i's performance curve on their website.

The 21 knots steady windspeed you mentioned is about 11 m/sec, so according to the specs, the Rutland should have been putting out 9 amps at 12 volts, or 4.5 amps for your 24 volt system. That would add up to 40 Amp hours vs. the 8 AH that your monitor measured.

I'd be unhappy with that, too.
.

Did you have a wind generator, Hud? What kind of real practical output did you get from it?

I didn't have high expectations -- I have a diesel generator on board and didn't expect the wind gennie to do much more than keep up the batteries when I'm off the boat. But this thing doesn't appear to be capable of running even an anchor light!

My father has solar on his boat, and not a giant array of panels, either. In sunny weather, it runs his whole boat for days on end (admittedly a smaller boat, but still!).

[mbianka]

Here's some video of my 48 volt Marine Air-X in about 20 knots of wind:
THE BIANKA LOG BLOG: HAPPY AT THE HELM!
Putting out a steady 100+ watts.

[DeepFrz]

What was the real wind speed at the altitude of the 914i? A wind speed measured at some place "close by" doesn't mean that is what the Rutland was seeing. Just sayin...

[Hud3]

Originally Posted by Dockhead

Did you have a wind generator, Hud? What kind of real practical output did you get from it?...

No, I don't have any experience with wind gennies, but the performance you quoted seems sooooo much less than advertised, I'd wonder if something is amiss with the setup, or perhaps the unit itself.

DeepFrz makes a good point. Proper weather stations report wind speeds at 10 meters above ground in unrestricted flow. You'd see less at the level of your boat, and maybe there are local features affecting the wind speed at your location. Still, with the output at only 22% of the spec sheet curve value, I wonder.

[Dockhead]

Yes, of course, a good point. My masthead is at 75 feet. But it was blowing a hoolie last night, and the Rutland was spinning its little heart out. Gusts of 35 knots were surely no less than 25 knots at deck level. Still I never saw more than 90 watts, and even that for only the briefest of moments. I question whether these things are practically useful for anything, if this is their normal performance. I guess I will contact the manufacturer. Maybe they gave me a 12 volt one by mistake?

[sailorboy1]

I have no persona experience. But in my mooring field there are LOT more boats running wind gennies than have solar panels. And I know some of those boats are liveaboard types.

It sounds like something is wrong with your system somewhere.

[Jim Cate]

G'Day Dockhead,

Interesting observations! We have one of the dreaded Air-X turbines mounted a couple of feet above and behind our solar panel arch, offset to the port side by about 5 feet and about 12 feet above the waterline. I have noted that the air flow in this area is quite turbulent when lying head to wind, and that this quite obviously affects the performance of the turbine... rapid changes in RPM, changes in the direction that the turbine is facing etc, all while lying in a fairly steady wind pattern. When lying with the wind from other directions the turbulence is less, and performance is more consistent. Perhaps you are suffering a similar condition.

As to performance, we don't have a battery monitor that records amp-hours in/out, but I have seen over thirty amperes (12 volt system) in gusts of 30+ knots, and fairly frequent steady readings of 15 amps with masthead windspeeds of 25 knots or so.

Cheers,

Jim

[barnakiel]

Well, if your batteries were full then it should produce 'nothing'.

Most windgens deliver as per their graphs. Just load the battery enough and you will see any monitor showing the max numbers.

You cannot add to a glass that is already full. Drink some.

b.

[Dockhead]

Originally Posted by barnakiel

Well, if your batteries were full then it should produce 'nothing'.

Most windgens deliver as per their graphs. Just load the battery enough and you will see any monitor showing the max numbers.

You cannot add to a glass that is already full. Drink some.

b.

All my measurements were made when the batteries were down at least 25%. But besides that, even if the batteries were full, the generator should at least be covering the load on the system. If the batteries are being discharged, then the wind generator can't be turning down the output because of full batteries.

[barnakiel]

It is difficult to tell when the battery is 75% full (25% down) unless you charged it first, then removed 25% of juice from it. Sometimes people say of 25% based of voltage and many do so talking of voltage under load. Etc.. - a winding road.

I would adopt a softer attitude and assume that yes it can - e.g. if it is voltage-based regulator and the voltage is high enough. Also in half a dozen other cases.

Try to run the test with heavy load on the batteries. Look up the regulator's specs and watch if it kicks in when the voltage drops to the pre-set value. You may have a faulty regulator but this is rare in a new installation.

A quick and messy way to measure things is to drag any small battery onboard (a local garage will probably lend you one), discharge it to say 11.6, load it with equivalent of expected windgen output and see how many Amps / Ahs the windgen delivers then. If it delivers 1 A then yes the regulator is probably busted.

BTW from my experience in gusty/turbulent harbour conditions divide the graph data/2.

b.

[Brazil]

My Air breeze will produce between 5 and 10 amps @ 12V in the conditionds you described.