my laptop was manufactured in 2006, and purchased as a refurbished model in mid-2010. the two t4300 processors were first manufactured in 2009, and the bios revision is likewise set to 2009, so i guess it got upgraded at the store. i should probably think of it as a 2009 model. nonetheless, it came with vista pre-installed, and is not a high-end machine at all.
usb 3.0 didn't exist until very late 2009, and you were probably unable to get your hands on a low-end consumer grade laptop with usb 3.0 ports until 2011 or 2012.
so, i must have usb 2.0 ports. and, if there's any further question about the issue, msinfo is clear enough about it:
why am i pulling more than an amp, then?
not 900 mA. 1.03 A.
see, those were my two options, logically - either i'm pulling more than i should be, or the device is restricted in what it can pull. it makes no sense that i'm getting over an amp out of the usb 2.0 ports. but, that's the actual answer.
so, the fan is indeed drawing at 2.5 W as advertised, and it's not a lot, for what it is. i'm not going to be able to drive this any further. that's as strong as it gets.
how, though? well, i guess that either the electricity in the board is faulty, or i got a very late usb 2.0 revision that can draw at usb 3.0 levels. well, do you have a better explanation?
i think that 500 mA is pushing it for a solar panel on a led light. i'll look into it, but it doesn't seem like a worthwhile investment, i don't think. rather, i've got it plugged into the wall socket drawing 2.5 W. there's a second usb slot; together, i can pull a maximum of 5 W from the wall over usb. so, i'm better off getting a second similar fan, maybe one that's just a tad bigger.
right now, i've got the 90W fan at half speed, which i hope is 45W. together, it's 47.5W. if i push this up to 50W, and i "only" save 40W, that's still pushing 30 kwh, or 15-20% of the total usage.
or, maybe i'll find the right solar cell technology, after all.
so, here's my updated information, in regard to the things i use frequently and want to get down to the 1.5-2.5 kwhish range:
ac fan (on full) - 0.08-0.09
ac fan (on low) - ??
laptop + monitor - 0.02-0.03
lights - 0.01-0.02 (per bulb)
modem - 0.01-0.02
usb fan - 0.002-0.003
also:
stove: 0.4-0.6
desktop pc - 0.2-0.3
coffee machine - 0.15-0.20
90s laptop - 0.05-0.06