Direct Downwind Faster Than The Wind #4 (DDWFTTW)

Yes, in theory you could go up-stream on a river in still air, by using a propeller to push the still air down-stream, powering the propeller from the water flowing under you.

And I am not talking about self-starting (I just saw that video). I would consider the self-starting pretty equal to real life if you self-start as in the video but then turn on the treadmill slowly and turn off the fan at some point (ideally soon).

Does it work if you put it on a treadmill that does not move and turn the treadmill on slowly? This would be equal to an outside situation. Everything stands still at first. Your demo is equal to the outside scenario of lifting the vehicle of the ground, waiting until the prop is up to speed due to the wind, and then setting it on the road and letting it go. Does it work without this "push"? You may need a really long treadmill though.

Would it work on ice or other low friction surface?

So there is a gear system that runs the propeller driven by the two bigger wheels when they are moved by the treadmill?

Yes, the prop and wheels are connected by a direct "transmission".

I would like to see the source of the wind, the direction of that wind, the speed of that wind and the speed of the running mill. It is clearly possible to run a device like this faster than the wind if the wind comes at an angle from the side. There is no data showing wind speed in this video. I cannot see the fan and where it is. What if the fan blows at 30 mph and the treadmill runs at 20mph? How can you make sure that the treadmill and the wind speed are exactly the same? I am not convinced.

There is no fan. The road moves while the air is still. That's our wind.

Gunstick is right.

It's an electric motor with a pulley system, running a propeller. The motor is in the treadmill, the tread and wheels are the pulleys.

What makes it look strange is that the frame which should hold it all together appears to be missing, and that is where gravity comes in to hold the "pulleys" against each other.

The power for the whole thing simply comes from the wall outlet. With an increased pulley ratio, you could probably make the thing rocket across the room!

Yes, the treadmill provides the power, just as the big electric motor provides the power in a wind tunnel, and just as the sun provides the power of the wind outdoors.

he puts energy into the system by running the threadmill agains gravity.