Fieldlines.com || Did my homework

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Reviews - Diaries - Our Products

Did my homework
By harley1782000, Section Wind Posted on Tue Mar 24, 2009 at 07:13:04 PM MST
Now to figure out what is good....

Well first i would like to say that i have been staying in the shawdows on the board reading and getting some ideas and information. This board and users are awsome.
Now with what i found out. I have been keeping track of my wind speeds for about 8 mths now where i live. I have on average of 5 to 10mph winds during each month. I live in Pennsylvania, out in the country on a north side of a hill. I am down in a valley (Kind of). I have very little trees around. I have a tower that I can get 35 feet in the air with. Now my question to all you out there is what size wind turbine would be good. I am looking on a 24 volt system just to use the power around the shop and maybe for a green house. Now in my township that I live in they have some restrictions on things in the air, as they call it. They are looking at cosmetic, nothing ugly as they would say it. I can have the tower by my shed so the run on wire can be kept short to the batts. I also would like to be able to maybe go from 24 to 48 volts system down the road with some solar and a 2nd turbine. I have great sun too!!! I do weld and work with metal so that part is easy to me. Electrical back round is ok, Not the smartest about it but ok. I do work with towers and do climb them so the tower part I understand. Just the size of a turbine confuses me alittle.
I can not wait to hear what some of you guys have in mind.
Thanks

Did my homework | 5 comments (5 topical)

Re: Did my homework (3.00 / 0) (#1)
by bobfandango on Tue Mar 24, 2009 at 03:15:39 PM MST

The basic idea you are looking for is that power produced is proportional to swept area ==> double the area, double the power. Said another way, if you double the diameter of the blades, you get 4 times more power (since the area is 4 times larger). Since you are in a low wind area, getting usable power will require something pretty large I expect. First, read this:

http://www.otherpower.com/windbasics1.html

With that kind of wind, you aren't looking at much power... BTW, the difference between 5mph average and 10 mph average is enormous. If you've gathered actual data on the wind over that time, plot a histogram and compute the mean with Excel or something. At 10mph windspeed, you are looking at around 100 watts out of a 10' diameter axial flux turbine (*maybe* up to 140 watts if your turbine is exceptionally good). That would be 2.4 Kwh per day of energy.... very very little. Look at it another way, you could power a single 100 watt light bulb all day. Anyhow, to get serious power at that windspeed will require serious size...

Another consideration is where, exactly, you measured this speed. I suspect you did so at ground level which isn't at all accurate. At 35', it will be higher and more consistent. I realize that your local regulations may not a allow it, but try to get your turbine on something much higher. There is way more wind up there.

Anyhow, good luck...

Re: Did my homework (3.00 / 0) (#2)
by harley1782000 on Tue Mar 24, 2009 at 04:35:31 PM MST

I meassured the wind at 30 feet. I should have not worded the average at 5 to 10 mph, Sorry about that. The actuall average was 12.78 mph for 6 mths. I have no clue why I said 5 to 10mph. So disregard that. Now the average guest for 6 mths was 22.94mph. Thanks for the input and will read the link. Thanks.

[ Parent ]

Re: Did my homework (3.00 / 0) (#3)
by bobfandango on Tue Mar 24, 2009 at 08:26:03 PM MST

Heya....

12 something average is actually pretty good. For every 25% increase in wind, you get almost a doubling of power production. So, from 10mph to 12.5 mph, you'd expect to double to roughly 200 watts. Still not a lot, but averaged out over 24 hours a day, that is pretty good for an off-grid home for a couple of people. But I have to ask... What kind of anemometer/data logging equipment are you using? Proper time averaging must include the time that the wind isn't blowing. Does your data include that time? The bike computer based anemometer designs you see on, for example, otherpower often have an averaging function but don't include the time when no wind blows.

Anyhow, if you have proper data logging equipment, then GREAT! That is decent wind... For your first turbine, I would go with a ten footer like you see here:

http://www.otherpower.com/turbineplans.shtml

I'm just finishing mine and it was great fun, but a pretty decent undertaking even though I have ok mechanical and electrical aptitude. I'd never done any welding or metal fabrication so the learning curve there was kinda steep. Sounds like you are better off there than I, but perhaps less so in other areas. Anyhow, it is fun, relatively cheap, and a good way to get into things. Once you have that under your belt, going to something like the 17 foot models may be feasible if you've got the time and money.

Take care...

[ Parent ]

Re: Did my homework (3.00 / 0) (#4)
by harley1782000 on Wed Mar 25, 2009 at 11:00:20 AM MST

Well the anemometer I use is from Taylor. It is nice little stand alone system that gives you averages every six months. It dosen't tell you time for the averages. I would like to get one that hooks to the computer to better track the wind and sun. If they make one that tracks sun intensity and how much you have per day.

I have Otherpowers book they just did and Hugh's. So I got good plans and it explains alot on what I need to look for. Thanks for your replys and info. It's nice to have people to ask question to when you get stuck or just are plain lost.

Thanks

[ Parent ]

Re: Did my homework (3.00 / 0) (#5)
by heynow999 on Tue Apr 14, 2009 at 04:21:34 AM MST

You don't need to bother to measure sunshine in your area as there are very good records that have been kept for a long time. Wind is very specific to an area, but with solar you only have to worry about shading. Here is a program that will give you a good idea of the sunlight in your area.

http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/

Did my homework | 5 comments (5 topical)

Menu

� create account
� How to use the board
� FAQs
� search the board
� Google search the board

Login

Make a new account

Username:

Password:

Total Views

��143 Scoop users have viewed this posting.

Related Links

� Also by harley1782000

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest � 2009 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!