You can take any dc motor and couple it to a spinning wheel to generate electricity. If you had the right motor and gearing then you could generate the proper voltage without having to go through inefficient voltage conversions.

I am surprised at the claim of 125-300 watts from the pedal a watt. I've heard numbers around 100 watts for a normal person. Remembering how much the old flip down bike generator lights slowed me down when i was younger, I think now I'd be lucky if I could power the tv remote with my bike, let alone the tv.