Critical Infrastructure Protection: Protecting the Electric Grid from Geomagnetic Disturbances, Report to the Committee on Homeland Security and Governmental Affairs, United States Senate [open pdf - 4MB]
"Space weather refers to the impacts solar activity can have on the space environment, including the propagation of material that can cause electromagnetic events on Earth. When the space weather is severe, it can cause a large-scale GMD [Geomagnetic disturbances] that may disrupt the reliable operation of the U.S. electric power grid. GAO [Government Accountability Office] was asked to examine the availability of technologies that may mitigate the effects of large-scale electromagnetic events and the issues and challenges associated with the usage of such technologies. This report addresses: (1) what is known about the potential effects of GMDs on the U.S. electric grid; (2) technologies that are available or in development that could help prevent or mitigate the effects of GMDs; and (3) factors that could affect the development and implementation of these technologies."
Government Accountability Office: https://www.gao.gov/