Highly-integrated MCUs from suppliers including ADI, TI, and Freescale, offer designers the ability to create effective PLL grid-synchronization algorithms.
While solar and wind farms promise to deliver significant amounts of power in a clean and renewable way, very rarely is the power user close by to the power generators.
Wind power has been recognized as a viable source of "free" energy for hundreds of years. Since it pre-dates the petroleum economy or even the industrial revolution, it seems odd to refer to it as an "alternative" energy source.