A bicycle power generator
 

Now, I figure there's not gadget made yet, but I was wondering what the actually probability of tying up a generator to the grid would be? Easy? Hard? Anyone have any DIY resources?

Instructables has a lot of ideas. I would think you could use those and hook them up to a grid tie inverter without any problems.

http://www.instructables.com/tag/?q=...c=on&sort=none

As I recall, there are some kinds of induction motors that will push back into the grid just by pushing them a few %rpm over their rated speed. Connected with a freewheel and some gears to your crank, and it seems real doable.

Not aiming for grid tie, but I'm going to tackle a bike based DC generator: http://ecorenovator.org/forum/applia...generator.html

I did this a year or two ago. I used an old single phase 1/3 hp induction motor and one of those bike trainers with a fan. I removed the fan and put a small lovejoy coupling on and mounted the whole thing to a wood board. I mounted the motor to the board aligned with the coupling. I monitored the power thru a mechanical watthour meter like utilities use. I could tell the direction of power flow from the spinning disk. It worked :), but not well for my pedaling abilities :o. I could back feed only 20-40 watts while maxing out my pedaling power. Most of the power was used just getting the motor to pass zero power (between using and making power). Plus the ratio was a little too high feeding a 4 pole motor (1725 rpm). I believe 3 phase induction are the most efficeint way to do this but there have to be capacitors of a certain value on the unused phase(s) (I'm currently looking into this for wind power). Either way, small scale induction grid tie hasn't appeared to be very practical. I did the same trainer set-up with a DC motor and had a much more efficient set-up, but no grid tie. You could always try matching a dc motor with an Enphase grid tie inverter:). That would probably be the more efficient way of doing it with grid interaction.

The contraption is mostly still together, minus the motor. So I took some pics of it. The dc motor is a 1/2 hp 100v 1800 rpm (still wrong for my ratio). I imagine a dc treadmill motor would be an excellent choice for the ratio my set-up has. Or one could make a larger roller that contacts the bike tire to better match the generator. The induction motor is boxed away so no pics of it.