I'll take a stab at the math (hah, we all know how THAT goes with me)... but jokes aside, something like this:
You're making 40mA at 4.28V going by the notes in the pic, yes? I'll run with that.
Let's say you want to charge my phone... it has this in it:
So you need to generate 3500mAh to charge it from completely discharged.
There's conflicting penny drop rates, but there's easy resolve if one of them is calculated. Let's go with the 1 ft per second for now to make the math easier...
1 ft per second, 60 ft per minute, 3600 ft per hour.
So 3600 ft would be 40mAh of energy.
The battery will need 3500, so 3500/40...
87.5 hours for a full charge.
3600 ft per hour for 87.5 hours:
315,000 feet the pennies would need to fall...
~59.66 miles of thread...
Ok, now for the "2 seconds per foot" version...
Still talking just shy of 30 miles of thread.
Even spider silk won't give you enough strength with a small enough diameter to cram all that on a spool that would fit on a stepper... unless you know something about physics I don't
So, as they'd say on a certain TV show, "Myth Busted"
Anyone, please, feel free to correct any logic/mathematical issues, but I think I got this one nailed. Sorry Norm
Steve