The last post is ok for portable use - I didn't know that you could run induction motors like that with capacitors without grid (mains) power. If you have grid power and who doesn't?, then you can easily have grid interconnected AC induction motor and feed your power into the house wiring and if you produce more than you use turn your meter backward (of coarse if your meter is allowed to turn backward, here in Ontario, Canada they will turn backwards). If your meter is not allowed to turn backwards, you can still slow down your meter by the amount you produce or stop it.
Here is how it works. You plug in the motor into 120V or 220V, whatever your electric grid is in your country or 3 phase, if you have it. When your motor is running at whatever RPM, then you turn it by a fas motor or windmill or bicycle pedal power and you turn it faster then it is turning when it runs, you automatically make it a grid-connected generator that produces the same exact power as your grid (house) electricity
No inverters, batteries. The control that you have to have is to have spin the motor faster than it normally runs, then connect it to your house power.
Keep in mind that it will only produce as much power as the motor is rated at, i.e. almost 750W for 1 HP motor, but you have to have little more than 1 HP driving it or big enough propeller to be able to generate at least 750W (see propeller sizing elsewhere in this forum).
So the only this makes sense if you have a source to drive it other than your electricity in the house - still all the same laws of physics apply - you can't create more than you put in (because of inefficiency of both source motor or windmill and generator). Of coarse you cannot use another motor to drive the generator and expect to see the meter slow down or turn backwards.
So hey if you have this rotating source to turn a motor faster then it turns hooked up you have a grid interconnected generator.