Just one fan?
written by ljkhjkk , December 17, 2006

Why not have many fans and generators all the way up the stack instead of just one at the bottom?

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written by monotonehell , December 17, 2006

Not completely sure, but my "physics gut" tells me that you can't get the same amount of air to do "more" work. There'd be a point where x turbines would stall the air rising to a point that they wouldn't turn.

chimney effect?
written by Jinks , December 17, 2006

Multiple turbines up the chimney would have a greatly diminishing return since every time a hot air molecule hits the turbine blade it loses some of its speed & heat energy and would have less energy to transmit to subsequent turbine fan blades.

I was wondering, tho, how a taller chimeny increases efficiency of the turbine, which they claim it does in that video. Cuz the minute I saw that turbine at the base of the chimney I thought, whats the point of such a tall chimney?

Chimney Size and Turbines
written by Hank , December 17, 2006

I'm taking their word for it. Multiple turbines, I know, would end up decreasing the energy produced by the tower. Though I'm at a loss to explain why.

As for the height and width increasing efficiency, I have no idea...but I believe them.

Chimney Draught
written by Western Infidels , December 18, 2006

I was wondering, tho, how a taller chimney increases efficiency of the turbine

Air is pushed up and out a chimney because the pile of hot air inside it is less dense than the cool air at the bottom of the chimney, which pushes the hot air up.

A larger pile of of hot, low-density air in the chimney will move more air than a smaller one, and in particular, a very tall pile of hot air tends to cause air to move through a chimney relatively fast, which is what you want for use with a turbine. Check out the Wikipedia article on chimneys.

I expect that it's possible to design a single turbine to extract all the useful energy from the chimney, and doing so, and putting it at the bottom, is simply cheaper and simpler than using a stack of turbines.

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written by icke , December 18, 2006

as you can see is this movie quite old, the german administration closed that experimental power plant a few years ago.
but i'm not 100% sure.