An official report prepared by John Kappenman, an independent consultant, was commissioned by The Oak Ridge National Laboratory in 2010. The report is summarized in The JASON report on Impacts of Severe Space Weather on The Electrical Grid, project number 13119022.
JASON is an independent group of some 60 scientists that advises the United States government on science and technology that could have national implications. It is run by the non-profit making MITRE Corporation in Virginia.
There is a massive amount of information in the report which was published in November 2011. For the technically minded, transformers are discussed in detail, highlighting the problems that space weather impacts could, and does have on them. There are examples from around the world of the damage caused to electrical grids when a coronal mass ejection hits the Earth. There are details of different types of space weather, their effects and likely outcomes of such incidents.
Kappenman based his findings on past space weather, the effects felt at the time and how the advances in technology since that time would be affected by a similar event.
Page 51-54 of the JASON report is of particular interest. It summarizes Kappenman’s findings. It is somber reading.
More than 300 transformers destroyed.
130 million people in the United States lacking power for several years.
1-2 trillion dollars of economic losses.
A US map of vulnerable transformers with areas of probable system collapse encircled. Credit: National Academy of Sciences.
At risk transformers in the same scenario
( To make the writing legible the map is way too big so you can read the details in the JASON report, page 53, here. )