According to smartgrid.gov here is the explanation of the Smart Grid technology. There's a growing number of smart grid jobs in this burgeoning industry.

What is the Smart Grid? An electrical grid is a network of technologies that delivers electricity from power plants to consumers in their homes and offices. A smarter grid is different in a few important ways. First, it uses information technologies to improve how electricity travels from power plants to consumers. Second, it allows those consumers to interact with the grid. Third, it integrates new and improved technologies into the operation of the grid. A smarter grid will enable many benefits, including improved response to power demand, more intelligent management of outages, better integration of renewable forms of energy, and the storage of electricity.

The Smart Grid is an automated electric power system that monitors and controls grid activities, ensuring the two-way flow of electricity and information between power plants and consumers—and all points in between. Up and down the electric power system, the Smart Grid will generate billions of data points from thousands of system devices and hundreds of thousands of consumers. What makes this grid "smart" is the ability to sense, monitor, and, in some cases, control (automatically or remotely) how the system operates or behaves under a given set of conditions. In its most basic form, implementation of a smarter grid is adding intelligence to all areas of the electric power system to optimize our use of electricity.