Scirocco and arctic weather

[Henrikki Maatta]

Hello all fellow wind enthusiast and greetings from Finland

This forum seems to be crowded by people who are in the know about Eoltec Scirocco, so I came here with my question. But let me first explain my situation:

I do have a summer house in finnish lapland, 750km away from my house. I spend abt 4 weeks a year there, some other people maybe another 4. During other times I need power for monitoring equipment and possible remotely stared ad-hoc heating. It is an off-grid location, inland but surrounded by lakes. Although I do have a Lister generator, I prefer to use small wind to generate my 240VAC, used mainly in cooking, electronics and such. Few solar panels that I have do not do much good as arctic circle is less than 100km away.
I did the cheap mistake in the version 1.0 of my wind project. I bought cheap chinese 5kW (FD5000 by Yangzhou shenzhou wind-driven generator co. ltd) generator and it did not work for more than a month at a time. Electrical 240VDC turning motor did die in several occasions and I lost set of 60 batteries due to lack of charge during first winter. I really cannot recommend that thing to anybody.

As you can imagine, the winter is very harsh up there and only the most rugged hardware can take the beating. Wind speeds are not too fast, but it's not uncommon for the temperature to go under -40C.

So now we are in version 2.0 of my wind experiments. I have decided to scrap the current generator, maybe to sell the blades and generator online to highest bidder and purchase a western made, more durable unit.
I still sdo have my 24m lattice tower, which has proper foundation and a brand new 20x 12V 300Ah battery set, which I want to reuse.
After extensive research in the Internet I have started looking into Scirocco as no.1 candidate.

I understand some of you are financially involved with Eoltec and therefore little bias, but I need info and experiences about the weather resistance and specially ice and snow handling of the WT. It can rain wet snow that immediately freezes up in there so I would like to hear how Sciroccos have managed in Canada. You guys have winter too, right?


Henrikki

Ps. It seems pretty difficult to purchase a Scirocco here in Finland. I have mailed and called among other the Scottish reseller, but no-one wants to even quote me a price. Lets see if Eoltec them selves want to sell me one. I would have preferred a complete set from a reseller with breakers and all, but I ques I can source them from somewhere.

[Rob Beckers]

Hi Henrikki,

Welcome to Green Power Talk!

Besides running this forum, my business is the distributor for Eoltec's turbines for most of North America. So, yes, I'm biased. That said, I have no interest in spreading false information or promoting junk. :eek:

As you noted, we get similar temperatures to yours here in Canada. How low it will go depends on how far north you dare to venture. We get -35C here in Ottawa (luckily not too often), and this is the south of the country.

The problem with low temperatures is that metal gets brittle when the temperature drops below a certain point. That temperature depends on the composition of the metal. I've talked to Eoltec about this, since we had people up north that wanted to install a Scirocco. Their response was that they feel it's fine at temperatures down to -40C and possibly -45C. However, going below that point will get you into the range where you run the risk of brittle fractures of parts. I am not a mechanical engineer, so if there's someone who knows more about this please chime in. My understanding is that it's the high-tensile pieces, such as some of the bolts/studs in the Scirocco, that have the highest temperatures at which they turn brittle. That is one part of it. The other is that the grease used in bearings and slewing rings is regular lithium grease. It hardens at some point (also down around the -45 or -50C range), causing problems for the bearing surfaces.

The Scirocco was engineered to withstand extreme wind speeds (and it does, 60 m/s is pretty extreme!). It was not engineered to withstand particularly low temperatures. It is possible to make a turbine for very low temperatures, but nobody looked at this for the Scirocco. Eoltec is not particularly interested in doing so, since you get into specialty metals, and greases, and the market for such a turbine is so small. So that is where things are at. If you get temperatures below -45C you'll be a guinea pig; maybe the turbine will survive, maybe it won't. If your weather is a bit like ours, you get the lowest temperatures during very clear nights without any wind. If so, that would be the best case for the turbine to withstand it, since it will not be turning. It is a risk though.

-RoB-

[Henrikki Maatta]

Thanks for your honest answer

It is pretty similar to the one I got from Eoltec directly. They do not want to go below -40C and I appreciate that. Those conditions do deserve some respect. Also the off-grid kit they did use previously seems not to be avail anymore. So Scirocco is not an option for me. That's a pity.

Next best thing I can think of is the Spanish Bornay.

http://www.bornay.com/eolica/en/latest-news/9/our-customers-opinions/13 .

They seem to be happy to put theirs into colds way. It would also be around 6kW and reasonably simple design to minimize points of failure.

Does anyone have any experience with Bornay?


H

[Rob Beckers]

Hi Henrikki,

From the little I've heard Bornay makes good turbines. I don't have much info on them, and no direct experience to say much (good or bad) about them.

Realize though that just like Eoltec, Bornay did not design that turbine for very cold temperatures, and I am fairly certain that they did not test it for that either. You're just as much a guinea pig with their turbine as you would be with a Scirocco. Just because they don't object to you putting it in cold weather doesn't mean it will work, or that they have any certainty about its survival (unless they have one running in a very cold climate, but most manufacturers will quite happily let you dig your own grave if they can sell a turbine).

As to offgrid use of grid-tie turbines/inverters: There is a way to do this, which works very well. Regular battery based inverters will move energy both ways; from the batteries to the house grid, as well as from the house grid to batteries if there is a source on that grid. Xantrex and Outback, two big inverter brands, support this, under the name "AC coupling" (do a Google search). It allows for a regular grid-tie inverter to be hooked up to the house grid (created by the battery based inverter), and any excess energy not used up by the loads will flow over the inverter back into the batteries, charging them. The downsides are that it costs more (you need both a battery based inverter, and a grid-tie inverter for the turbine), the battery based inverter needs to be sized to support the full current/power from the grid-tie inverter, and charge control needs to be provided to avoid overcharging the batteries (this can be done with a simple contactor though). The big advantage is that the turbine uses MPPT, which makes at least 25% more efficient in extracting energy from the wind than a battery-tied wind turbine of the same size would be.

-RoB-

[Steven Fahey]

Calgary gets some nasty cold snaps, too. My turbine is "home-built" therefore I cannot offer a personal opinion about one manufacturer's equiment.

An engineer working for the wind turbine manufacturer can tell you what temperature range the machine can withstand, or "is designed to" withstand. Some want the temperature boundary as a warranty against failure. Others want to test in the most extreme conditions to discover the limits of its endurance (usually not company engineers).

I read in a book by Paul Gipe that a Proven turbine was operated in Antarctica for a time. One would regularly find temperatures below -50C. Opportunities to safely lower the tower for inspection and maintenance may be rare with nearly constant winds. Probably some lessons learned from that experiment, so maybe you could talk to Proven about how long (or "if") it survived.

[Steven Fahey]

Oh, almost forgot to say: Welcome to the forum!

Beautiful site, despite being a challenging environment for a tower. Those trees are 20 meters tall? 30?!

[Henrikki Maatta]

I agree that Eoltec engineers are playing safe here by not recommending Scirocco to me.

It is amazing how difficult it is to purchase these things. First Eoltec did not want to sell one and now European resellers and Bornay themselves do not even bother to respond to emails. I wonder if cold is such a scare for all of them or what is wrong. I am starting to understand the reason why small wind is small business.


And Steven:

Thanks for the welcome.

I would be happy to run an arctic test site for any of the manufacturer for privileged access to their engineering. Even though I do live up there, I do have online monitoring and actually a setup of a weather proof Digital SLR with remote control on a turning turret for online surveillance.

The trees are only 12-15m long, as they do not grow too tall during the short summer and as the sun is not above but all around. One can see the situation better for the pic I attached.


Henrikki

[Cor van Houtum]

Hello Henriki,

(quote)
I bought cheap chinese 5kW (FD5000 by Yangzhou shenzhou wind-driven generator co. ltd) generator and it did not work for more than a month at a time. Electrical 240VDC turning motor did die in several occasions and I lost set of 60 batteries due to lack of charge during first winter. I really cannot recommend that thing to anybody.


My name is cor van Houtum and we import and sell the SWG turbines in the netherlands and belgium.

Looking at your photo's I think you are right about the electric yawing motors.
You have one of the first series of this generators and it is well known by now that there where isues with the yaw controll.
The first types had no "anti-twist sensors" and twisted the cables insite the tower.
Also the PLC steering was not done right.
The fuses in the controllerbox where to small
and when they blow then there is no yawing possible anymore
Most people upgraded the fuses to more then 20 amps.
but the real problem was not fixed with this.

The PLC setup was in my opinion mutch to high in all cases.
and the dumpload to small calculated.

We never imported this version but we started on level II.

This one has a anti-twist and a more heavy yawmotor , but the plc steering values are still mutch to high.

Out of our expierence with this turbine we may say that the turbine should never operate above 330 volts DC.
When the voltage rises above 350 the RPM gets mutch to high for this big windmill.

The blades start turning with so mutch forge that they want to stay in place,
I mean the same place like a frontwheel of a bicycle bottum up that you trow turning.
it wants to stay in a certain position.

And now you get into the everlasting circle of trouble.

The generators spins up
The power can reach easely 7000 watts (with a 5000 watt turbine)
The inverter system or charge controller will not dissipate all this power.
The generator does nor realy feel that someone is tapping its power
Result is that the speed increases even more.
Then when the speed is mutch to high allready the voltage will be about 450 volts.
The PLC gets awake and connects the turbine to the dumpload resistors.
The dumpload resistors are calculated for a 5000 watt turbine.
So the generator will go on spinning up.
Then the plc decides to start turning the yaw motor
Can you imagine how mutch tork you need to get this out of the wind ?
Right , to mutch for this motor and the fuses blow.
No they do not blow because we allready changed them to a higher value !
The motor burns.

End of story (when you are lucky)

Solution :

buy a new type 5kw turbine (version II) with controller
Change the dumpload and fit a extra dumpload unit on the pedestal.
change the dumpload voltage protection in the plc program to 305 volts
change the 30 degrees yaw on voltage to 310 volts
change the 60 degrees yaw on voltage to 315 volts

Put the AURORA inverter table to get its max 6200 watts at 300 volts.


I hope my info helps a bit for you

I have 2 pcs of these turbines in stock (allready modificated)
And you get 2 years full warranty from me when you use it as i discribed.

And yes am biased to.

Kind regards

Cor van Houtum

http://www.draaistroom.net