mast for Navitron 5KW turbine

[suzdobson]

Hi Ivan,
A really helpful discussion between you and Bargeman comparing the two sizes of turbine!

So I have been looking at the possibility of getting a 5KW turbine instead - having looked at our electricity consumption this week with all the cold weather, it definitely seems the way to go - if we are going to make any dent on the overall consumption.  I have found that the company in Lowestoft called Sun Energy Alliance would be prepared to erect it and connect it for us.  Their technician had a question for you regarding the mast - he said they would do the installation if the mast had a ''gin pole''.  Could you tell me if this is the case - I am of course out of my depth with gin poles!
Another question would be - do you use two Windyboy2 with this turbine and do you have all the necessary bits of kit so it can be assembled by SEA?? Is there a problem with overload or do you have a devise for protection?

I also contacted Hugh Piggott, who gave me lots of sound info and advise about the various turbines including the Whisper 500 - which I really appreciated.  So going for the bigger turbine seems more sensible and cost effective in the long run.
Thanks to you and all you other techies I am getting to grips with the relative figures and requirements etc 

Kind regards ..... Suz

[Bargeman]

Hello Suz,

Unless you have some site specific wind measurement data that suggests otherwise, I think there is a strong argument for considering 2 x 2kW turbines rather than a single 5 kW machine.

The chart I have attached shows that 'breakeven' between the power curves for 2 x 2 kW turbines  and a single 5kW turbine occurs at 11 m/s wind speed. For a site with 5m/s average wind speed, speeds greater than 11m/s can be expected to occur less than 2% of the time. For the rest of the time, taken together the two smaller turbines will outperform the 5 kW turbine. If you have sufficient lebensraum I would seriously consider this option as it should also end up costing less.

Hope this helps

[suzdobson]

Hi Bargeman,

Thanks for the info - that does make sense.  I think we are more windy than the average - but not that much more.  It also means if one fails the other will still keep churning away!
Do you know if they have to have separate cable or can they be linked up first and then the cable run to the house?

I really appreciate your help
Regards ........ Suz

[f828]

Suz and Bargeman

I have two anemometers whizzing around at the moment checking the wind performance here prior to committing myself to any particular wind turbine purchase.

Based on the very early figures I have here I would say Bargeman is correct!

Here there are: anemometer 1  showing 8.22 kw  per day for a 2kw Navitron, therefore times 2 suggests 16.44kw.

                       anemometer 2 showing 9.24kw  per day for a 2kw Navitron, therefore times 2 suggests 18.48kw

The figures for the 5kw are as follows:-

                       anemometer 1 showing 14.37kw per day
                       anemometer 2 showing 15.72kw per day.

Hope this helps

[suzdobson]

Thanks d...

Well done - that's really helpful!
Have you any mean reading for actual wind speed in m per sec?
Cheers ...... Suz

[f828]

Yes, I can get a full report from the system based on a spread sheet file...
the software is from www.windsurvey.co.uk....so I could send you a copy if you wish?

[Capcave]

How would you go about combining 2 (or more) 2kw turbines into a single lead back the consumption point? Batteries are relatively easy I guess as the charge controllers just feed the bank but if you were using immersion heaters I guess you would need one per turbine?

[suzdobson]

Dear F828,

Thanks again ...... I would be very interested in your data......... should give a bit of a snapshot.  Where are you and what is your average wind speed?

Cheers  ........ Suz

[Bargeman]

Hello,

Am I right in thinking that you are proposing to grid connect your turbines, Suz ? If so then my initial thinking is that the turbines should function independently with separate cables, charge controllers, inverters, switch gear etc. (note that the cables could be run inside the same conduit).

I have to give some thought as to quite what happens at the export meter, i.e. whether both inverters could feed the same export meter. On the face of it, since both of the inverters would be endeavouring to synchronise with grid voltage and frequency there should not be any problem provided they are connected in parallel. (get this verified by someone more knowledgeable !)

From my investigations two small grid connect inverters, 2.5 kW, cost about £1,462 each, about half the price of a 5 kW inverter, £2,924 (let me know if you can get better prices than these). You will need to cost it out in detail but on the basis of some rough costings I have prepared for another project, I would be suprised if the overall cost of installing 2 x 2kW turbines turned out to be greater than for the 5kW turbine, even with some duplication of kit.

f828 - I would be most appreciative if you were able to let me have a copy of your spreadsheet via PM. Also very interested to know what you think of the kit and software supplied by windsurvey.co.uk.

regards

[Alan]

Hello Suz

You mentioned you had a electric boiler, if it is fed from a  single phase supply presumably with no solid state controls, it will probably have a thermostat just switching the boiler heater on / off.
The windyboy inverters will probably shut down on a grid voltage low fault when the boiler starts and start to grid connect again taking several minutes. No one as yet on the forum has indicated what the maximum D.C. voltage with the 5 K.W. generator free spinning is likely to be. The 10 K.W. will achieve 860 V.D.C. 
Ivan’s achieved voltage on the 2 K.W. machine could be considerably higher than the Windy Boy inverter can take with a full size mast in an unobstructed location. The dump load will require to be fail safe in the event of grid failure.
 Your comments on the company in Lowestoft willing to connect to the grid for you. You need to ask if he has suitable qualifications to satisfy building control regulations. As mentioned else where on the forum even a Degree qualification in electrical engineering will not allow you to carry out basic house wiring any more.
   

Regards

Alan

[Alan]

Hello Suz

If you want to come over and have a chat. The budget can run to a cup of Tea.
You are most welcome

Regards

Alan

[suzdobson]

Hi Alan and Bargeman,

Yes I have an electric boiler and an electric oven - so presumably the Windy Boy will cut out everytime there is a large pull from the grid.  Somewhere on this forum someone said it was set to cut back in after 30 sec. after the power had stopped being used.  Also that it can be programmed to cut back in sooner.  Ivan also says in the answer to '' Does Navitron have a failsafe over voltage device?'' that he is working on this - will take a couple of months.  He also told me that the 2 Kw turbine only gets up to 450 volts when free running - the Windy boy can cope up to 550/600 apparently He still wants to add a failsafe to this tho'.
I think I may well go for the two 2Kw turbines as there seems to be a case for this at lower wind speeds ,rather than the 5 KW.  THen presumably there is less of a problem with overload too.
Thank you for the kind offer of tea Alan - I see you are somewhere in Essex - so maybe after Xmas I will have the time for a trip out.
The company in Lowestoft seems to be a big accredited one that puts up Proven and others.  So they should be able to give me more info on assembling.  Ivan has not answered my question about the tower but they said they would do it if there was a 'gin pole' on the mast - he has not replied yet.  I am just trying to find out how it all links up - in what order and with what safeguards and important points.  I am not an electrician but these things can surely be explained in English.

I get the feeling Ivan likes to 'play' and do the 'boys toys' bit - which is fine but it gets the lay person like me nowhere and after all we are all supposed to be saving the planet - not just playing - aren't we
Anyway guys ......... keep up the good work - it's all useful info!!
Cheers ...... Suz

[Ivan]

Sorry for late reply - unfortunately this week has been pretty busy, so unable to reply to everything on forum over the last few days. However, as usual, you have received good information and advise from the many helpful people here on the forum.

Yes, the 5kW wind turbine does have a gin pole as part of the kit. The machine is sunstantially larger than the 2kW wind turbine - both in terms of tower height/diameter and the weight of the turbine itself.

[suzdobson]

Thanks Ivan for that - much appreciated - 

I am now, after good advise from all these guys, looking at the possibility of two 2KW turbines instead - as I suspect our winds will spend more time between 5 and 10m/s than anything more - these last two weeks excepted.  So can you tell me if the 2KW have gin ties too?! I suspect it does. It will be easier to talk to the techie in Lowestoft if I have all the info rather than going off half cocked!

Can you please tell me if what I have written as a summary of what I have read and understood, seems to be correct and is on the right lines.

To be continued I suspect .......... cheers ........ Suz 

[Ivan]

The 2kW wind turbine does not have a gin pole as part of the kit. Incidentally, in some cases it can be easier to use tower scaffolding around the tower once it is up, to attach the turbine rather than a gin pole - if you use a gin pole you must make sure that whatever you are pulling it up/lowering it down with is suitable for the kind of stresses involved. I have seen a very experienced wind turbine person drop a tower whilst lowering it with a gin pole, as his cable was not strong enough. It is not normally a problem, but it can occasionally happen.