The U.S. power grid system comprises multiple distinct intercon-nections of generations, high-voltage transmission systems, and local distribution systems that maintain a continuous balance between generation and load with impressive levels of eciency and reliability. is critical infrastructure is likely to see more changes over the next decade as a result of the proposed modernization of the grid system than it has seen over the past century. In particular, the widespread deployment of renewable generation (centralized and distributed), smart meters, synchrophasors, smart-grid controls, energy storage, and new conducting materials will require fundamental changes in grid planning and the way we run the power grid.