TheBackShed.com

Forum Index : Windmills : punch some holes in my idea

Page 2 of 2

Author

Message

Bolty

Regular Member

Joined: 03/04/2008
Location: Australia
Posts: 81

Posted: 10:20pm 16 Jan 2010

Copy link to clipboard

Print this post

It is good to see that you are experimenting with wind energy! Now that you have the turbine ready for use, you need to work out what you will do with the output energy. Firstly you need to estimate how much power the turbine will put out.

The 4ft turbine (I assume you mean diameter) will definitely NEVER make any noticeable difference to the temperature of your pool.

I strongly suggest that you re-read Dinges posting! He knows what he is talking about and has quantitatively explained why heating large volumes of water is not viable with a small turbine. He also explains very well why there are better uses of the power generated!

I would recommend that you monitor your wind regime so that you may be able to estimate your expected daily output of energy from the turbine. I am not in a position here to be able to do that estimation. However with a 4 ft very efficient turbine, I would expect that you would need steady winds around 7 m/s (16 mph) for most of the day to produce 1 kwhr per day. Remember that a doubling in wind speed has the potential to produce EIGHT times the power. Conversely a halving of the wind speed will produce ONE EIGHTH of the power.

I was at your stage of understanding nearly 2 years ago. I erected a 12 metre high 1 kw Chinese turbine. The blades are 2.7 m diameter. Over one year I would be lucky to have produced 100 kwh. I cannot be more precise, because my wind turbine is connected to a grid connect inverter which is also fed by 1kw solar panels. They have produced 1500 kwh in a year.

What I did not understand is that for most of the time I only get low level wind. The very windy times do not make up for the poor wind times. I do love my beautiful ornament in the sky. My neighbours also love it for their ability to see where the wind is coming from!

In contrast to my wind power, for my site, solar is a totally different story. I have been able to acquire 1kw PV panels and a grid connect inverter for less than AU$3000 installed. This will pay for itself in 4 years, as we receive $0.50 per kwh fed back to the grid.

My purpose in writing all of the above is to possibly save you some time in pointing you into a better direction with the use of the power that you do generate.

Good luck with your project!

KarlJ

Guru

Joined: 19/05/2008
Location: Australia
Posts: 1178

Posted: 11:22pm 16 Jan 2010

Copy link to clipboard

Print this post

congrats Bolty, the wind system you have should take 2000years to pay back.....

I'm sure you're not alone Phill has terrible spot with no wind too, of the data I logged 80/20 is a good rule of thumb.

i plotted this unto power produced and payback period obtained and concluded no commercially manufactured small wind turbines with their big tickets could ever be viable one exception --chinese one, they got pretty close to viable.....

perhaps it needs to catch more wind, blade mounts are simple, how about some extensions say 200mm per blade this would increase the capture area by 1.5m2+ or 30%

this should be good for at least 30% more grunt...

talk to Gordon 1st, he's down your way yes?

Luck favours the well prepared

Lortan
Newbie

Joined: 27/07/2009
Location: Canada
Posts: 7

Posted: 11:29pm 16 Jan 2010

Copy link to clipboard

Print this post

Yeah I kinda expect that the 4' diameter will get me nowhere for power. I agree with Dinges posting but right now I am not too concerned with heating the pool so much as just getting the hang of these turbines and what they do. I figure i get it running and then find a use for the power after. Unfortunately here in Alberta oil sand country the resistance to green alternative power is high and therefore grid tie is not an option. According to the specs on the 4' unit it is 200w.
Mean 7 mph = 6 kwh
9 14
11 22
13 30
15 36
I am sure this is open to all kinds of discussion and interpretation. The book gives me directions to build 4',6',8',10',12', and 14' models each one of course giving a larger watt rating. I built the first one small just to learn the basics and hopefully break the cheaper stuff first before I even try to attempt a larger unit. Any thoughts on my tower?

Bolty

Regular Member

Joined: 03/04/2008
Location: Australia
Posts: 81

Posted: 01:32am 17 Jan 2010

Copy link to clipboard

Print this post

KarlJ.
You are right that my windmill is uneconomic! However the learning, understanding and thinking that I have gone through as a result of this exercise are amazing and very rewarding.
Gordon works on small scale commercial wind turbines, and I am sure that he would not agree with your comment " concluded no commercially manufactured small wind turbines with their big tickets could ever be viable". It all depends on the price that you would otherwise have to pay for power, AND what your wind regime is! He has told me about commercial 2kw Skystream system installed along the SE coast of SA that produces more than 13kwh of power per day on an ongoing basis. Given that the alternative to the electricity would be via diesel, the economics in this case are viable!

Lortan.
As I have admitted above, the love and dedication to RE goes much further than economics. You are on a great path of understanding about a fascinating hobby and interest. As Dinges so capably explained, the really significant part is in realizing that consumption minimization is so important. Your awareness will spread to others!

Keep up the good work!Edited by Bolty 2010-01-18

Page 2 of 2

Print this page

To reply to this topic, you need to log in.