What's smart about the smart grid?

The paper explores the meaning of smart grid, concluding that the term is closely linked with enhanced sensing, actuation and control of power systems. It is suggested that such cyber-physical systems would be more meaningfully described as responsive grids. The paper provides a brief historical perspective of the decision-making that underlies existing, seemingly inflexible, grid structures. It emphasizes the future needs for responsive grids, as a consequence of inevitable growth in renewable generation and newer types of loads such as plug-in electric vehicles. The paper considers the cyber-infrastructure requirements for supporting controllability of highly distributed generation and load resources.