I encourage you to read this article by Jesse Berst in SmartGridNews today:
Why Every Utility MUST Learn the Word Transactive.
The only way that a truly intelligent, decentralized grid can work is via organized energy markets. Today the US grid has <20,000 utility owned generation plants and there are only few thousand small consumer owned generation facilities dispersed throughout the grid. In the future there will likely be many millions of endpoints the can produce or store power as well as many million residential, commercial and industrial energy management systems. This kind of network (just like the Internet) cannot be centrally monitored and controlled, much less dispatched via traditional voltage or frequency regulation AGC. It will become a "peer to peer" energy network facilitated by competitive energy markets.
The biggest barrier to full realization of the promise of transactive energy markets is inadequate transmission (and to a lesser extent, distribution) to fully enable the market. After all, for 100+ years the industry has built transmission primarily for delivery of power for large, central station power plants to remote load centers.
We'll be talking more about this in the future here and at The Energy Collective.