Wednesday, November 09, 2005

Wind Turbines

I've always liked the idea of wind power generation. One day I'd like to have a turbine on the roof of my house contributing to my household energy requirements.

There are a couple of major issues with current, propeller type wind turbines. Most turbines put the blades in front (upwind) of the support pole. This requires that the blades are very stiff, so they don't flex and hit the pole. This adds to weight and therefore cost, while also reducing efficiency as there is more mass for the wind to move.

Well, why not put the blades behind (downwind from) the pole, you ask? Seems obvious, because you can have lighter and more flexible blades. Unfortunately there are issues due to the turbulence created by the pole. There is a kind of "dead spot" behind the pole which causes the blades to lose pressure and flex towards the pole. This can set up a rhythmic flexing and can destroy the blades depending on wind speed/strength and rotation frequency.

Here is an alternate design that uses a vertical axis and doesn't have any of these issues. I'm not sure how feasible it is, but hopefully it can result in more efficient wind power generation.

As always, more information is available from Wikipedia here.

2 comments:

Anonymous said...

This looks just like what I've seen for years as turbines here in Australia - A 44 gallon drum cut in half, each half welded to a central spindle. Doesn't have to rotate to meet the wind, doesn't have dead spots, super cheap to build, pretty efficient because of the curvature of the surfaces. Nothing new under the sun, eh?

Anonymous said...

Hi Glen
I can't remember your email address, hence this message here.
You will be interested to see the viewers' winner for 2005 in The New Inventors (solar power generation). Future homes could be adorned with 44 gallons drum wind generators and solar discs. The Internet address is:
http://www.abc.net.au/newinventors/txt/s1487858.htm

Your 'environmentalist' Mum