Generating energy at your home or business, and selling it back to the grid is called "net metering", particularly Market Rate Net Purchasing.
Vancouver Renewable Energy Cooperative has done grid-tied stuff before. The Grouse Mountain windmill project shows some of the frustrations of working with BC Hydro. Apparently there are less than 200 houses connected to the grid so far (as of June 2011).
You cannot achieve synchronization between an inverter and a made-in-China generator. It's not the genset, it's the inverter who is picky about how stable the 60Hz is.
DO NOT WASTE your $$$ on single (large) inverters, buy what is called "micro-inverters", way more efficient and dirt/shade-forgiving… And no fussing with high DC voltage, straight AC out…
What is needed to take a family 50% off grid.