Good Morning
Yesterday I pulled our wind turbine down all by myself, really not as difficult or dangerous as I feared. Below you can see the red Blazer in the background. It is tied to the special cable we have on the gin pole. Sort of accidentally I left just enough slack in the cable that enabled me to gently tug on the rope attached to the top of the turbine, easing it over the edge of the pivot point, where it hung until I hopped back in the Blazer and moved it forward, letting the tower very slowly down.
Turbine-stub-bent. When I looked up at the turbine a couple weeks ago, it appeared that the top pipe called a stub, was too small in diameter, making it the weak link in the design. Yes, it was the weak link, but it wasn't too small. The top pipe (red) is two inch in diameter. The breakdown in the system came about because we added six inches to the blades, thus creating too great of a wind swept area for the tower and turbine housing designs. I'll post more information on the relationship between wind swept area and turbine offset (distance generator is away from tower for proper furling) The bottom line is that the turbine did not furl quickly enough during last months high winds and the extra wind swept area let too much force push on the top of the tower, bending the two inch pipe stub, which I should never have designed to be so long to begin with. As the name implies, the pipe stub is supposed to be stubby. I was trying to add extra height to the two twenty foot sections of tower we had lying around.
Turbine-stub-bent- seeing the bend up close is an eye opener. The power in the the wind is amazing. I put all my considerable weight on the top of the tower and it did not even begin to unbend this pipe. Unfortunately, the red pipe is tied in with the upper guy cables, so complete disassembly will be necessary to pull the turbine stub out of the tower for a proper rebuild, and perhaps redesign.
Turbine-stub-bent
Then, while inspecting the turbine itself I found these cracks in the stator. If you remember, the stator was a project Jackson, Henry and I performed on our kitchen table. Potting the coils, this is termed. It means after winding the copper into 9 coils using the super duper coil winder Kevin and I made at Luna shortly after we went to the week-long workshop at OtherPower in Colorado, they are very carefully soldered together and laid-out precisely in a mold, sandwiched with fiberglass. Polyester resin is poured into the mold, creating the plastic stationary part of our alternator. Anyway, it all went wrong, we couldn't get the stator out of the mold, and had to laboriously chip away the wooden mold.
The episode convinced me that we needed a workshop. and for the next year with the help of family and many friends our homemade wind turbine project was put on hold while we indeed build a wonderful shop. Once I had a place to work, I dug around in our backyard and found the stator still entombed in the mold, thrown down in disrespect I might add. Jackson, and Kevin now back on the project and I cleaned the funky looking stator and added a couple layers of polyester resin, declaring the stator "Close enough."
Well close enough rarely is just that, and it looks like the stator cracked in the places where we patched it a year later.
In summary, and I know what you're thinking, "About damn time."
These issues ought to be dragging my mood into the dirt. I'm fine. I don't have a complete plan in my head yet, but that's okay, I know Austin, Amelia and Kevin are finished for the season in Taos, and they'll help me figure our what to do. My life is getting back to normal, after my father's death last month. The turbine will need a little more effort that bending the pipe straight, but I know that thought was naive.
Maybe this is the push I needed to build a better turbine.
–
Brian Rodgers
