HAWT 2004 - 2009 - 2015 Evolution

From about 2000 I have been experimenting with my Down Wind HAWT designs.

The all new machine as seen in the other posts is a hybrid of the 2004 right angle bits and the 2009 blades.

The 2009 blades are very efficient by all my testing and with the generator I will be able to place it squarely an the graph compared to other systems.

I started with 12" blades and the right angle assembly still in use today, had to completely rebuild the over run mechanism and horz. axis bearings for 2004.

 

Over the years I went from 12" to 18" to 24" blades, at 4' in dia. I decided to go to an all new design in 2009.

 

I had access to some experimental SLA equipment and got to design and make a beautiful 5' dia system.



With this big of a turbine I needed a truly robust tower. As you can see my mill is in the lake, it gets an uninterrupted view of the winds from the SE to the SW.





Looking thru the water I have a 4 part structure that disassembles for winter storage, and 4 custom cast cement weights that stay right where they are over the winter. It makes about a 7' diam span and is easy to move anywhere as needed.

HAWT DIY Vert. Axis Rotary Contact 2 leads

This is my second attempt at a robust rotary contact. Commercial rotary contacts start at around $50 and go up fast so I decided to experiment with this design.



A key component of any HAWT is a good rotary contact, I have learned over the years that making things small and compact is only necessary when you don't plan or leave yourself enough room. This was a definite success; after I decided to use commutators from an electric motor. The vert. bearing pack is above.




The Rotary Contact if safely covered by the mounting tube, any rain water that seeps into the tube will not be a problem.

See my 5 contact version here

HAWT Stepper motor Rectifier Circuit

I worked out the rectifier circuit on the bread board.



Then went CAD to develop a nice machinable circuit.



Not knowing for certain what I'm going to be powering it has no additional components like a capacitor.




Mounted under the Stepper.

Hard to see but the with the nacel mtg. bracket in place the wiring loops around under the c/b mtg bracket.

HAWT Stepper Motor Generator

This is not the 1st part of my journey in HAWT experiments but it is the 1st post.

I somehow stumbled onto the concept of using a stepper motor as a generator. The number one advantage to me is not having a gearbox! this is really a major convenience. I have years of experience with CNC machines and have a pile of spare motors.

With the stepper connected to the vert. mill I was able to make RPM vs volts charts.

I used a double bridge rectifier to get all the results. Generally I consider HAWT RPMs to be in the range of 100 - 600 RPMs.

This is where the stepper is so convenient, it produces lots of voltage at these low revs.

With these good results I designed and machined a circuit board.

 This little circuit board is mounted below the stepper.

The system for mounting the stepper to the horz. shaft is Exactly like the mounting of stepper to a CNC axis. This makes the concept and the components readily available and easily understood.

The completed system; I will post regarding the rest of the mechanism subsequently. (it is a DOWN-WIND HAWT)

Further experiments have provided a more complete look into the power potential.