Lurking,Learning,Experimenting, now Building my turbine

[bvan1941]

Hi Folks,
Have been lurking and learning from you all. Read many,many, of your Diairies. Thanks so much for all your first hand experience and knowledge. It has been an invaluable website where a newbie can rely on straight forward information without worrying about being pressed to buy something !
My contribution is to say that all the technical information here is spot on!
I have built a small treadmill turbine ,31' pivotig tower and with 6.5' PVC  Blades to test the wind speeds during the period I'm building my "biig system." I am not trying to get any useful power from this project ,just have (5) 12V bulbs encased in a jar to absorb anything generated.Watching my first experiment operate at various heights,windspeeds (5-20knots) and blade changes, has been very satisfying and caused a multitude of questions from customers and friends about my motives--- and sanity! LOL
I've built my 12 volt Stator and have rotors and magnets (ordered /received from Ed Lenze) ready for assembly. Currently making the mounting and Thinkig seriously of taking Chris Olsen's advice by using the 8.5' POWER MAX blades for my first operating turbine. My intentions (based upon seeing the Treadmill's performance) for the new tower will be 45' high to get above local trees and use 3'' OD pipe with another pivoting system. When I learn how to send Pix's I will show past  and current projects.
By the way, have carved a two bladed prop (with all the attendent mistakes and redo's). Great experience and makes clear all that been said about blades being very forgiving yet still practical and useful with decent windspeeds. It's everything you all have each tried to say in your many inputs and answers to all us "Newbie's".
Again--------Thankyou all for your Knowledge, patience and this Site being here!
Bill
 

[ChrisOlson]

If you use those PowerMax 085's wind your generator (or adjust the air gap) so they run around a 6 TSR (350 rpm) @ 18 mph wind speed and you'll get the best performance from them.  They like to cut-in around 7 TSR and if you're using Ed's wedge mags 35 turns is what I ran in my 12 volt with those blades - and I had it close to 1 kW (65 amps) several times in 30-35 mph wind.
--
Chris

[bvan1941]

Chris,
Thanks for the reply. We run a RV Campground here in Panhandle of Fl. and I'm doing what I can between customers and chores. We usually have winds i 5-10kts in summer and 10-20 kts in fall,winter,spring of yr. After reading your report on the Powermax blades at those approximate wind speeds (5-20 kts), I didn't think I could make blades with better low speed performance. My generator will be in the 500-800 watt range IAW Ed Lenze's design. Thanks for the interesting posts of your projects and videos. when I get the turbine completed, will try postng pics for all.
Bill

[ChrisOlson]

That S809 airfoil is hard to figure out on those blades. I have a 13 foot 12 volt turbine with those blades on it and it has been running in IRP (Individually Rectified Phases).  I have it somewhat overwound so it runs partially stalled - or so I thought.

I have an anemometer that gives me the average wind speed for a 24 hour period.  From Wednesday morning at 8:00 to Thursday morning at 8:00 it recorded an average wind speed of 9.1 mph.  That 13 foot turbine made 109.4 amp-hours, according to the Doc Wattson on it.  On Thursday morning I rewired the thing star, which puts it in the ideal TSR range for a 24 volt battery bank, but I didn't change anything else - left it hooked to the 12 volt bank.  It starts charging at about 5 mph and around 60 rpm.  I watched it for a bit and it never gets above 100 rpm and it puts out about 14 amps turning so slow you can count the blades going by.

So I left it run that way.  This morning my anemometer said 9.0 mph average for the last 24 hours.  The Doc Wattson on that turbine said 159.2 amp-hours.  It made 45% more power into the batteries running severely stalled - about a 4.0 TSR - at approximately the same wind speed as the day before.
--
Chris

[SparWeb]

...So I left it run that way.  This morning my anemometer said 9.0 mph average for the last 24 hours.  The Doc Wattson on that turbine said 159.2 amp-hours.  It made 45% more power into the batteries running severely stalled - about a 4.0 TSR - at approximately the same wind speed as the day before....

Chris, I don't know if you'll find this reassuring, or disturbing, but what you describe is normal.  The power curve that I develop on one day will *not quite* match the power curve the next day.

There could be 2 hours of 36 mph wind and 22 hours of 6 mph in one day, but you'd still get 9 mph daily average.  You probably know that already.  Was it more gusty yesterday?  Stormy?  Hotter?

[SparWeb]

Bvan,

Hey welcome aboard and thanks for letting us know what you're up to.
Did the treadmill motor get those lights nice and bright?
You are well on your way to acquiring our addiction.

Steven

[ChrisOlson]

There could be 2 hours of 36 mph wind and 22 hours of 6 mph in one day, but you'd still get 9 mph daily average.  You probably know that already.  Was it more gusty yesterday?  Stormy?  Hotter?

No - the peak wind speed recorded by the anemometer was 10.5 and 10.8 mph, respectively, for the two days.  Temperature was about the same - in the high 50's.

The conclusion I'm coming to, after experimenting with S809's long term is that they perform better if you run them at lower TSR.  A peak of 6 TSR @ 18 mph is about the optimum for them for best all-around performance.  In low winds from 8-14 mph they can obviously be run at 4 TSR and they'll make more power than they do running at 6.5-7 TSR.  If you let them spin like a flat-face they'll make tremendous power in high winds and burn up generators because they pull down to about 5 TSR and refuse to stall.

I wanted to make Bill aware of that if he's going to use PowerMax 085's.  Those blades need to be rpm-controlled, use their torque and have them well stalled by the time the wind is blowing 20 mph or he'll lose his generator the first time the wind really blows.  Like I noted in my first post here, I've seen 1 kW into the batteries using that identical set of blades on a generator wound with only 35 turns of wire.  Bill indicated he wound his generator for the 500-700 watt range and that scares me right away - he'll burn it up if he leaves those blades faced into the wind at 25-30 mph unless he wound it with enough turns to stall that rotor.  And only 35 turns, as I found out, is not enough to do the trick because you'll have a runaway in high winds.  I don't know what the specs on his generator are - just putting the warning out there because BTDT.
--
Chris

[bvan1941]

Chris and Steven,
Thanks for the welcome and bits of wisdom. I regard you both with respect and will ensure I put your recommendations on my checklist of precautions. I will use gap width for fine tuning cut-in. I think I want a slow but useful out put in the coomon5- 10mph winds here and accept a modest but safe output in higher 15-30 gusts and winds of F/W and Spring.
With respect to the in-work Ed Lenz style magnets / generator, My stator has been wound IAW Ed Lense's advice to use# 14 ga. wire and  44 turns for a 7-8' blade. I don't want it to pull out of stall in 20-30mph wind and I certainly want it to behave and furl with an attendant reduction in power. When I get close to final mechanical assembly, I'll summarize on this Site what I've accomplished for constructive inputs before flying. I'm doing all my own electrical and welding. I don't want to do all this work and lose it all in the stronger winds of fall and winter!
The goal is:
-Charge 3-4 12V batterise
-Use this power to run some low voltage (LED) outdoor lighting
-Have and alternate backup method of generation with a future Solar System array
-Practice Construction for a possible "bigger" turbine
-Personal satisfaction
And Yah------ I think I'm gettin hooked !!
Bill

[ChrisOlson]

With respect to the in-work Ed Lenz style magnets / generator, My stator has been wound IAW Ed Lense's advice to use# 14 ga. wire and  44 turns for a 7-8' blade. I don't want it to pull out of stall in 20-30mph wind and I certainly want it to behave and furl with an attendant reduction in power.

You'll be fine with that with those blades as long as you pay attention to getting the tail light enough to furl it.  The generator you just built is the first generator I ever ran with those blades and I burned it up due to furling issues.  I had 45 turns of AWG 14 in mine.  It had enough turns to stall it, but my furling calculations were a little bogus and it came out of stall in 35+ mph winds and that generator lasted less than five minutes.  That's when I put the spin test to those blades and found out they'll hold in runaway freespin at 40+ mph and well over 1,000 rpm.  Finding my magnets was another issue - those were scattered halfway across the county and I never did find 4 of them.

The second generator I built for it was a 35 turn with two-in-hand AWG 14 (dual-wound generators have a steeper power curve and require less turns).  And I changed my furling from a gravity hinge tail system to a vertical hinge with a spring-loaded power limiter.  I haven't burned that one up but I've seen it push hellacious power in high winds.
--
Chris

[ChrisOlson]

That's when I put the spin test to those blades and found out they'll hold in runaway freespin at 40+ mph and well over 1,000 rpm.  Finding my magnets was another issue - those were scattered halfway across the county and I never did find 4 of them.

After blowing that generator and losing some of my magnets I made two other changes to my turbine designs - I started pinning the magnets to the rotors and added a half-wrap blast shield to the generator so if I ever have a runaway and it tosses mags, it directs the magnets straight down to the base of the tower instead of throwing them into the brush in the neighbor's back forty.

The blast shield also serves another purpose - it keeps rain off the generator, and keeps snow and ice out of the generator in the winter time.  I attached a photo of one of my turbines that has those PowerMax 085's on it with a shielded generator.

Stephen is right - building these wind turbines is an addiction - once you fly one you'll find you can't stop   
--
Chris