Posts Tagged ‘vertical axis wind turbine’

CR Especial v2.2 videos

Monday, August 24th, 2009

I finally got 2 of the videos of my cousin’s and my work on the Vertical Axis Wind Turbine (VAWT) in Costa Rica up.

Some extended information: Each of these turbines is 6 feet tall… the total width of the two turbines is 10′ … it’s pretty big and will definitely crank out the wattage!  We estimate that the payback period for these simple to build[1] turbines will be 2-3 years.

Each of these was built for about $250 excluding the generator, electronics and batteries.  We think and hope that they will last for at least the next 10-20 years with very little maintenance.  They are solid steel construction turning in automotive axle supporting ball bearings.

[youtube]http://www.youtube.com/watch?v=bSTCOtWx52g[/youtube]

[youtube]http://www.youtube.com/watch?v=ScD1xW9udF0[/youtube]

  1. built by 2+ non-engineers with a welder a drill and a few odds and ends from the local Costa Rican hardware store []

Back from Costa Rica

Monday, August 17th, 2009

I have just returned from my windmill building expedition to Costa Rica and have great news to report!  The wind is strong, the windmills are (hopefully) stronger, and after another trip in December they should be producing more than enough power to suit their needs.

I’ll be posting  a full how-to article on Instructables.com and here, pictures and Youtube videos as well in the near future… but for now here are those beautiful windmills!

It was fun and hard work.  And inspiring.  There are so many more ideas in the works!  Stay tuned!

greentheo with the turbines

greentheo with the turbines

CR especial V2.1 update

Tuesday, May 5th, 2009

Version 2.1 of the CR especial turbine has been completed and attached the base mounting structure.  .

Here is a nice shot of the turbine down in Waco, TX.

cr_especial_v21.jpeg

And a video.

[youtube]http://www.youtube.com/watch?v=5BZBJ2lzE5U[/youtube]

Dimensions:

  • 24″ diameter X 60″ blade height
  • 4″ wide blades constructed from 4″ drainage PVC cut into thirds.

Other stats:

  • All PVC for the blades, shaft and connections.
  •  Current mounting height.. about 10′
  • Total cost excluding generating engine – ~$50

A nice feature that Bryan added was putting a coupling in the middle of the shaft so that the blades could be phased into the wind spreading the torque of the blades throughout the rotation.

Performance and future work:

  • Wind down in Waco isn’t especially strong and consistent… but even so at 10′ and with really small blades, the windmill does turn.  Next steps:  Elevate to 30′, build replica in CO and take to top of Front range for testing.
  •  The blades used are 4″ wide, and have little aerodynamic lift.  The windmill often gets stuck facing into the wind in slow wind speeds. Next steps: Craft light wings which create lift and are closer to12″ long.
  • The diameter of the turbine is 24″, this provides the ability for higher RPM’s but lowers the turning torque.  Next steps: widen out to 48″ diameter and retest.
  • The height of the turbine is an overall 60″, not bad, but the 4″ PVC for the shaft can go to at least 2 times longer without causing flexing issues.  Next steps: increase height to 96″-120″

We don’t have any readings on the wind speed and power efficiency… mostly because we don’t have the equipment.

But… if you’re reading this, like the project, and have 300 dollars to donate to a tax deductible ministry please shoot me an email at munkey906 at gmail.com… we’ll get some good data recorded and analyzed asap!

Fluid flow over a Vertical Axis Wind Turbine

Wednesday, April 29th, 2009

Since I’m in the habit of being a Mathematician I can’t do anything that has a cost associated with it without simulating it computationally.

And so, since my cousin and I are building these large Vertical Axis wind turbines down in Costa Rica on the Lord’s dime (what’s worse than wasting my money?  wasting Consecrated dollars of course!), I wanted to get a feel for what the turbines could do in a laminar flow, not that wind flow at 20-30 feet above ground is laminar… but as stated in paragraph one I’m a mathematician, reality is just a detail to be worked out.

I found this simulator online which allows you to upload any design to be tested.

And I produced these videos – note: the acqua color is an area of low pressure, pink is high pressure:

A PVC pipe cross section at 45 degrees makes up the outer blades.

[youtube]http://www.youtube.com/watch?v=GVnopxl3wr8[/youtube]

A tri-blade VAWT.

[youtube]http://www.youtube.com/watch?v=pnN5Cp05kWs[/youtube]

A tri-blade VAWT with baffling on the outside.  The idea is to make the tri-blade more efficient by taking a turbulent flow and making it laminar close to the blades.

[youtube]http://www.youtube.com/watch?v=wpdnDWY-TyA[/youtube]