Commercially Manufactured Turbine Blades

[sahlein]

I'm posting this because it looks like blade building/testing could

turn into a full-time hobby/project/obsession.

Would appreciate input on available blades that are in the 15ft length

range which function well in 8-11mph winds.

I'm asking this because I already have a lot on my plate and it seems

dumb to introduce any additional engineering tasks at this point.

Thanks,

Joe

[erichtopp]

Just got a quote from Bergey Wind Turbines for 3 of their 10 KW size blades for $5000 USD. Also got a quote from Jacob's wind turbines for 3 of their blades on a 20 KW at $6000 USD. Hope this helps to give you an idea of cost. Although, you could make your own set of Jacobs wooden props for a lot less money for sure if you want to work on them yourself. Also I've chatted with an aerospace engineer recently and he suggest covering the wooden props with Helicopter leading edge tape as this would make them last a long long time. Some of the Jacobs wood prop mills have lasted 6 to 7 decades, amazing!!!!!!!

[sahlein]

What are they made of?  Is Jacobs still using wood?

Joe

[erichtopp]

Yes the 10 KW and 17.5 KW units still use wood blades. You can get replacement blades for the 20 KW units in wood as well I believe. If you purchase a complete new 20 KW unit they come with fibreglass over a foam core for the props. Jacobs used sitka spruce to make their blades because this wood has the highest strength to weight ratio known. Sitka spruce is also used in building wooden aircraft airframes and wings ( trust me the real aircraft fly quite well when they're made out of sitka spruce ).

[sahlein]

Thanks for the input.

No way I'm giving somebody five grand for a whittling job!

I've worked with fiberglass and am learning about carbon fiber now.

I can get pre-fab carbon fiber tubes to make spars and go from there.

Joe

[aeroenergy]

We design and manufacture blades.

http://www.fieldlines.com/story/2005/11/28/144711/76

regards, Nico van Meurs