Leo Mauler wrote:
The "low cost dirt cheap" method would be to charge car batteries off a solar or other renewable grid ("bicycle power" is inadequate to the task of charging car batteries, though it might run a laptop) and use them with an inverter to run a laptop's conventional AC adapter.
According to one of the charts at http://www.minoura.jp/index-et.html, I'm putting out about 350W when I ride my trainer in the morning (for short periods, admittedly). My laptop's power supply puts out 72W.
Those with more electronics experience might be able to rewire the laptop to use DC power directly, but stepping down the car battery to the laptop battery power level might require enough complexity that just an inverter with the existing AC adapter might be more workable.
My laptop takes 16 VDC, and automotive adapters are readily available. Couldn't you just use one of those?