Suitable Turbine for Really Bad Climates

[domajo]

Hey,

I have never posted here so a brief intro is in order. I am a Mechanical Engineer who has sort of lurked around this forum and others for a while. I am an apartment dweller in Philadelphia PA but I grew up in the middle of nowhere in Idaho. I never thought I would be able to build a small turbine but have the opportunity to work on utility scale wind power design at work which I love.

My brother who sort of randomly bought a pig farm in the Philippines about 10 years called me the other day. The farm is growing a lot and they are starting to stress the local power grid and run up some serious power bills (local power is $.25 per kwhr), relative to the productivity of the farm (he doesn't make anything on the farm). Most of this power is pumping which is required to wash pigs and provide for the locals during droughts. Of course I was glad to be helpful and pushed him towards the Hugh Piggot design which could be made locally (inexpensively) and might "Catch On" if we could teach his workers to make it.

A brief survey of wind averages showed wind in that area was at least Class 6 (Awesome!). This lead me to think about extreme winds, so I looked it up, the highest winds in the Philippines were recorder just 6 years ago, a whopping 320 km/h (198 mph)(DOH!), it was pretty far away (about 500 miles) though. Additionally, this area seems to get alot of hardcore tropical weather.

My understanding of the Piggot design is that it pretty tankish and could probably take the heat if the furling was working correctly, and the blades were done correctly. It doesn't pump water directly, which would be very nice. The tower might be a problem but we might be able to double up on the guy wires.

Does anyone have any thoughts on this situation in terms of maybe using a different design (I need to find the parts in the philippines) changes to the existing design. Places that the HP design usually fails etc. Personal experiences with failure (strictly related to turbines please!) are greatly appreciated.

Sorry for the monster post!

-Doug

[niall]

hi Doug

hardcore tropical weather i think ( never experienced anything remotely like it ) is going to be very hard on a windmill or anything mechanical ....and putting a dent in the power supply bill is going to be tough with a mill even a big one ....

the neo magnets can be frail and prown to corrosion sometimes ( not always but it can happen ) and lately their very expensive ....up nearly 100% a while back   

possibly running the courses sounds a great idea , and Hughs designs are ideal for that ...he is  working with ferrites again ...( they never rust )....he may publish some ferrite plans in the future , kind of wait and see ....

what about a purely mechanical pumper mill just for the water ? ...should be lots of info available on the net ....

"My brother who sort of randomly bought a pig farm in the Philippines"....sounds like just the right guy for the job ..

with Hughs designs you do your own maintenance ...thats a big plus point ...very hard ( probably impossible ) with off the shelf alternators ....a nice option to have 

[Wolvenar]

Parts are always a problem for stuff in that area.
My step grandmother was from the Philippines, I have a fair knowledge of the area, but far from expert on its weather.

I seriously doubt any home built wind generator will be low maintenance dealing with the weather it will experience there.
From experience here, with the extreme temperature shifts, humidity, and general wide range of weather, nothing much likes it and I am always up to my ears in maintenance of this or that machine.

There is the extreme heat in the middle of the day, high winds, then that rainy season.

Off hand here is a short list I can see you would need to plan for.

You will have to build for protection from burnouts.. the heat can be there even with high wind. a brake would probably be a requirement in my opinion. An air core stator would be a melted and charred piece of dung in short time without one.

I would build a centrifical trip device that engages that brake until manually reset. 
An electric release/re-arm of sorts that has to be manually activated once any unexpected storm had passed, so your not climbing that tower to reset the brake.
I don't think such a system is out of bounds of DIY, even in the Philippines

Also as Niall mentioned, ceramics would probably be best in that wet environment. Neos just don't get along well in humidity. 
Nickle plating has failed for me on most any outdoor device I have employed them in. Smaller ones I have as a door holder in a cupboard below our sink are even very badly rusted, in only a few years ( hard drive magnets)

I also agree with Niall that a mechanical pumper and storage tank high enough to provide adequate pressure might be a more effective solution for the water issues. Just might need to be careful of contaminates, and growth of bad stuff in it, Solar heating it to reasonably high temps might deal with that? I am no expert on that matter, just rambling thoughts there.

As far as saving money on power bill..

What kind of KWH use per month is this farm using?

I don't know if any of this helps but just my thoughts.

[Wolvenar]

Maybe Oztules can pitch in here?
He has the most similar weather you can get to that location.


Also one more question. What kind of threats are there to the security of such systems.
This will come into play when you start dealing with a bunch of valuable copper, and batteries.
I know some locations over there are rather unfit for anything not protected like Fort Knox.

[Bryan1]

<<<< beats that southerner to the first post......

That 2hp motor conversion which was my first conversion a few years ago is still going strong and eh when it's blowing a gale and trees are falling over the first thing I do is run upto to the shed to watch the amp gauge try and break the glass. Sure the furling sorta works on it but after letting 100K + wind hammer it many times it just keeps going and going.

Ok now for wet/tropical weather one can put seals on both ends of the motor to stop the ingress of water and fully pot the magnets on the rotor just incase moisture does get in.

That 4kw conversion I'm doing is still stalled as I'll be getting a pro to do the rewind but finding a decent say 7kw motor with dual windings so one can do the star/delta double combo could be the go so only the rotor needs to be machined up and neo magnets potted. If the climate does destroy the motor and the rotor is done properly it would be a simple case of putting a new motor on and reusing the mag rotor.

Cheers Bryan

[wilfor03]

Hey    domajo,

You may want to consider an AC Servo motor (hefty, big, large) to help supply the power you'll need? Flea-bay has a bunch of em, and often times,

some good buys. Low maintenance, high output, reliable, just build a mount for the servo, carve some blades, some electronics, and down the road

you go.

Bill

[domajo]

First of all, thanks of the info. Excellent!

Bryan, where can I find more info on your conversion?

I have been told that the Philippines ends up with alot of left over American computer trash including hard drive magnets...on the other hand now that you mention it  I have a hard drive magnet on my fridge that has also started to rust and peel. Does potting (making sure they are completely covered in epoxy) these things help, so that they are not exposed to the elements?

I'll look around for a pumping wind turbine design but I hesitate to leave something as proven as the Hugh Piggot design for somebodies experiment (however exciting it might be). The only "proven" path would be to use a cots wind pump but there is just never going to be a return on investment for someone that only makes a few dollars a day, especially if they can't maintain it. I'll look around more at this option.

Finding and sealing motors maybe an option, aren't they less efficient though? (due to the low rpms?)

Are there any examples of this centrifugal trip device? Wouldn't a sudden stop rip the blades or nacelle off at hurricane speeds?

We are considering erecting 3 of these things, security is a problem at 2 of the sites, we are considering this....

Burnout sounds like a problem, would it be advisable to disconnect the load at a certain speed/amperage? Would that even help?

Back to work.....

-Doug

[David HK]

Hello,

I live in Hong Kong and have built two of Hugh Piggot's turbines - 2.4 metre diameter swept area aerofoils and a 12 volt stator.

Piggot turbines willy only fail due to poor quality engineering, a lack of attention to detail, neglect, and penny pinching on materials. I went in the opposite direction and improved the design and quality significantly, thus intending  them to last beyond a lifetime subject to good maintenance from a caring owner.

Hong Kong often receives the same typhoons that have passed over the Philippines so the machine construction and tower design need to be carefully planned.

The attached photograph shows the machines on ground level storage mountings.


David in HK

[niall]

disconnecting the load  ....
 
mmm...probably not Doug ....the mill needs to be under varying load for the furling to work properly , its a kind of balance situation ...without a load it will go into wind seeking mode ...over speed and destruction ......erm ...i think

nice alts there David .....very nice  ....i,d definitely like one of those ........

[Wolvenar]

The idea is to have it timed so its going to engage at a speed that exceeds the safe zone, yet only applies enough braking power to slow it to a slop. I would not throw a rod in and bring it to an immediate stop.
I would suggest also a shorting of the coils which would help bring it down enough to do a controlled stop.
Once stopped the blade presents itself as a smaller wind load,and does not take as much to hold in place.
This has a weak point if the winds pick up in one sudden gust and never back down overpowering the brake until self destruction (not terribly likely).

TomW has a zubbly (motor) conversion similar but smaller than Bryan1's that has literally been indestructible for MANY years, and unless i missed something it has been very low maintenance, even when the blades were damaged hitting the tail
I have also done a few motor conversions.
With rewinding they work incredibly well, and the generator really is near indestructible.
This kind of setup is not air core, and does have a certain amount of drag, but given the reliability, I would think its worth it.
The very fact is has an iron stator allows it to wick a LOT of heat away, and you have essentially NO danger of the stator warping due to heat.

This leaves the need to protect the blades from over stressing in high winds.

As far as proven design. Wind pumpers have a history SO much longer than any electric wind generator it's not even a contest.
I'll find an example of an age old American wind pumper. ( like the ones the railroad used)

With the exception of seals, and bearings on occasion, which today are VASTLY improved, they were incredibly resilient.
Part of this is do to the fact they are stopped and the blade is locked when not in use.
 Sometimes this included furling that worked both automatically, and the operator could also furl some of them and lock it that way both furled and with the blade locked in place.

Any which way everything becomes much harder to manage when you get larger.
Smaller Hugh Piggot designs most times do not suffer easily from burn out.
But this becomes more and more troublesome as you get larger.
In contrast the larger these motor conversions get the harder it is to overheat them, but at some point they get near impossibly to manage unless you are young, tough or have many friends with industrial equipment.


Next year I am going to attempt a tower build and motor conversion on a scale I would NEVER recommend for the average Joe.
Just because I have the resources. I am pretty sure though in 5-10 years repairing a failure on this setup will be a highly unlikely possibility.





   

[shawn]

Hi Domajo
If you wanted  to go with the Hugh design I noticed Glen at the backshed posted a simple manual furl lock on his small mill this could be used as in those huge (hurricane) winds locked up and shorted should do the trick . you would still have to build the tower strong enough though lots of steel heavy guys and lots of concrete.
actually this locked in furl mechanism should work for all upwind types of windgens and it seemed simple to add, you just need to be there to lock it 

[tomw]

Wolv;

The 2 meter (6 foot) diameter Zubbly conversion has never suffered a blade / tail impact. It does not furl.

It has withstood sustained 70 MPH storm winds unscathed. I never shut it down for storms unless I was over voltage on the batteries. It has exceeded 1KW in output in the scary winds when girlie furling turbines would get shut down.

Our weather here @ 43° north is everything from -40F windy and bone dry to +120 F and high 90's% humidity. We do see high winds occasionally and sustained 40 MPH + are relatively common and 70 + MPH are not rare. No salt water within several hundred miles, however.

Ther blades were dried nearly to dust and badly  eroded  when I took it down to refinish them and the tail and to check the rest of it.

There is a guy making me replacement blades and I expect it to outlast me when I reinstall it later this winter.

Both the motor windings and bearings seem to be in as good a shape as when I installed it 5 or 6 years ago. Not exactly sure when but Zubbly (RIP) died in 2007 and it was flying before then but on a shorter tower. Beyond worn finish on wooden tail and prop it really needed absolutely no maintenance. I don't think Zubbly used anything special to treat the wood just polyeurethane which is not exactly a high grade outdoor finish.

It is not even a "sealed" motor and has openings on both end bells for air flow.

If he wants bullet proof I would go with a motor conversion with properly treated wooden blades.

And a photo or three:

That tower is 65 feet to the motor shaft.







Just from here.

Tom

[Wolvenar]

Ok sorry about that got your setups cornfuzzeled ..

[MadScientist267]

That's a nice lookin' bird there Tom.

Whatcha use to get it up in the air tho? Probably safe to assume there isn't any tilting that thing up and down... ?

Steve

[ghurd]

Zubbly (RIP) died in 2007

It does not seem like that long ago.
I never met him face-to-face, but I sure do miss him.

If I am not mistaken Tom, Zubbly told you to "fly it til it failed"?

And Zubbly meant the PMA.

G-