August 21’s total solar eclipse and the solar industry

The earliest recorded eclipse in human history occurred during the 22nd Century BCE. Legends state that two Chinese court astronomers were executed for their failures to predict and prepare for the eclipse, as eclipses were believed to be omens foretelling the health of kings. Since then, eclipses repeatedly have been associated with kings and their nations, with legends and superstitions linking eclipses to the deaths of King Henry I and Queen Anne Neville.

While it’s unlikely the upcoming eclipse on August 21 will result in the overturning of any kingdoms, it pays for the solar industry to be prepared nonetheless. The last time a total solar eclipse was viewable on the continental United States was in February of 1979, a time when the state of the American solar industry was very different than today. The totality of this eclipse will be passing in a line from Charleston, South Carolina to Salem, Oregon, but its impact will be felt across the entire continent.

With 10% of California’s generation coming from solar (representing 50% of solar production nationwide), the upcoming eclipse promises to be a challenge. California Independent System Operator (CAISO) estimates a loss of over 6,000 MW of generating power during the eclipse. Experts estimate 70 MW/minute will be lost as the shadow approaches, and then solar production is expected to ramp up at a rate of 90 MW/minute afterward.

Fortunately a similar eclipse crossed Europe in March of 2015. This will give California utilities insight into how to prepare for the drop in production. Electricity reserved from gas-fired and hydro-electric plants should be enough to offset the loss, particularly given California’s glut of snowfall this year. In the future, storage resources like batteries could also play a role. Similar plans to those in California are in place for North Carolina, where the solar industry is smaller but still a presence. The North American Electric Reliability Corporation (NERC), a nonprofit corporation formed to “ensure the reliability of the North American bulk power system,” expects no major disruption to the grid’s reliability but does recommend utilities prepare and study the eclipse for the future.

{This article contributed to OH SUN by Cal Kielhold}