According to an April 2017 white paper by the North American Electric Reliability Corporation (NERC), total solar capacity (distribution and transmission connected) in the United States has increased from 5 MW in 2000 to 42,619 MW in 2016. This increase is significant because “utilities are expected to experience a sudden (less than 5 minutes) increase in load that was previously being supplied by behind-the-meter photovoltaic generators. This increase in load may cause local ramping and balancing concerns which should be investigated by each area’s respective utility.”

In laymen’s terms this is important because electricity must always be flowing on the electric grid. If it stops, then you can have grid failure (blackouts). So if a large part of an area’s electricity is being served by solar, and the sun goes dark very fast, then the grid managers must match that sudden drop of solar power with electricity from other sources.

Think of it as a bucket of water. You have a hole in the bucket, and you must pour new water in the bucket at the same amount that is leaving from the hole. That is what the electric grid managers do every day, and they are very good at their jobs. Now imagine while you are pouring water into your bucket, the bottom of your bucket just disappeared only to reappear five minutes later. How do you keep water in that bucket? When the bottom is suddenly re-attached how do you not overfill the bucket? This is what will be happening on the grid while you are outside taking selfies in the dark.

Grid operators do have some experience in this. A total solar eclipse occurred across Continental Europe, Nordic Countries, and Great Britain in 2015. In developing their white paper, NERC reviewed the European assessment of the 2015 eclipse to “glean applicable lessons from European assessment.” NERC and local utilities knew this day was coming for a while and have put their “A-Team” together to come up with a solution. And much like John “Hannibal” Smith, they have a plan. You can read their report and recommendations to avoid grid failure here:

http://www.nerc.com/pa/RAPA/ra/Reliability%20Assessments%20DL/Solar_Eclipse_2017_Final_4-25-17.pdf