The U.S. electric grid is a vast physical and human network connecting thousands of electricity generators to millions of consumers — a linked system of public and private enterprises operating within a web of government institutions: federal, regional, state, and municipal. The grid will face a number of serious challenges over the next two decades, while new technologies also present valuable opportunities for meeting these challenges. A failure to realize these opportunities or meet these challenges could result in degraded reliability, significantly increased costs, and a failure to achieve several public policy goals.

This report, the fifth in the MIT Energy Initiative’s Future of series, aims to provide a comprehensive, objective portrait of the U.S. electric grid and the identification and analysis of areas in which intelligent policy changes, focused research, and data development and sharing can contribute to meeting the challenges the grid is facing. It reflects a focus on integrating and evaluating existing knowledge rather than performing original research. We hope it will be of value to decision makers in industry and in all levels of government as they guide the grid’s necessary evolution.