Mini solar tower using fresnel lens - version 7

This is, verison 7, likely my final attempt to turn a PC fan using rising hot air heated using a fresnel lens. It's almost identical to version 6 except that I've added an actual tower in the form of a 5' long, 3" diameter ABS tube.

The full mini "solar tower".

Mini "solar tower" (screen solar air heater) mounted without the PC fan or the tower.

Screen solar air heater and its placement in the light cone.

The result was that the tower caused the paper turbine to turn faster than without the tower but it still couldn't turn the PC fan.

Mini solar tower with paper turbine.

Mini solar tower with PC fan.

As a sanity test I blew into the paper turbine and the PC fan with three different air flows each (see photos below): gently, medium, hard. Even blowing gently the paper turbine turned faster than it ever did the the solar tower. Only by blowing the hardest did the PC fan turn and in comparing how fast that same blow strength turned the paper turbine with how fast it turned on the solar tower, there's no way this solar tower can ever turn the PC fan.

Blowing on the paper turbine.

Blowing on the PC fan.

Video of the mini solar tower

Here's a video of the mini solar tower testing in action, including the blow test comparisons. Enjoy!