This hearing by the Homeland Security and Government Affairs Committee examines the extent to which the electric grid may be vulnerable to the threats of solar weather or a high-altitude electromagnetic pulse. Protecting the electric grid is a monumental challenge, and the threats facing it are many and varied. The grid’s physical infrastructure is necessarily spread throughout the nation and often cannot be protected from severe weather, sabotage or vandalism. Likewise, utilities themselves are encountering an enormous task in protecting their computer networks and fighting off cyberattacks. The threats of solar weather and high-altitude electromagnetic pulse are unique in that they can affect a vast region of the country. They may damage assets on the grid that are expensive, difficult and time-consuming to replace.