Loquin hit on what others have found on other forums. Over on Endless Sphere, The question of pedal generators comes up often. Its been calculated to be only 50% as efficent as just pedaling the bike at best, and many applications are going to be worse. meaning if you could go 20 miles on your bike by pedaling, by using a generator to charge a battery and run a motor, you have reduced your range to 10 miles.
"But wait! I didn't mean charging the battery exclusivly, I only ment using the generator to extend my range. I'd charge the batteries at home!"
Right. Same principle. If you could normaly go 20 miles on battery alone. and you also have the fitness level to pedal 20 miles, by using the pedals to generate power, you could extend your range to at best 30 miles. HOWEVER, if you skipped the whole generator mess, and just pedaled along with the motor, you would extend your range to 40 miles.
As for the solar charger, Ypedal hits upon the best solution in another thread. it just isn't practicle to carry a pannel big enough to charge the battery during the day. Solar panels just don't have that much output for there size. But a home base pannel, charging up some car batteries all day long, could be used to recharge your bike over night. Such a system could also be used for emergancy power around the house, so it has added benifits.