We’re currently running off an analog system that is about a century old. The smart grid is a digital system. At the national level this is supposed to allow different energy sources to tap into a unified system more easily, and route electricity more effective to homes and businesses. Even now large companies often have strategies for using more energy at night so they’re not drawing power during the day when everyone needs. (To use one example, some buildings make ice at night in the summer and use it during the day to air-condition the building.) Some companies also have backup generators, and have a deal with local utilities to go off-grid and onto the generators at peak times to ease the utility’s load; in return, they get a break on their rates. The concept of the smart grid is to make these kinds of efficiencies more widely feasible, in anticipation of a time when some houses may have enough solar power to sell it back to the utility at certain times.
At the home level, the digital system also means lot more control as well as awareness, and this supposedly leads to efficiency; e.g., if you could count the dollars falling out of your refrigerator door you would close it more quickly.
The benefits of the smart grid to homeowners seem limited to me, but for what it’s worth, so did the benefits of the Internet when I first heard about it. Still, I suspect that the media, in looking for a human interest angle, is overly focused on the programmable-toaster aspect, when the smart grid is really about the unsexy business of updating infrastructure.