The Impact of the Total Solar Eclipse on Electric Grids Across the U.S.
Anticipated Decline in Solar Generation
Electric grids in the U.S. are preparing for a significant decrease in solar generation during Monday’s total solar eclipse, spanning multiple states. NASA predicts the path of totality, when the sun is entirely obscured by the moon, will last from 1:30 pm CDT to 2:35 pm CDT.
ERCOT (TEXAS)
ERCOT expects the eclipse to affect Texas from 12:10 p.m. to 3:10 p.m. CDT, causing solar power generation to drop to about 8% of its maximum output. This decline will see solar generation decrease from over 10,000 MW to approximately 1300 MW over two hours, while demand fluctuates between 48,899 MW and 51,539 MW.
MISO (PARTS OF MIDWEST, SOUTH AND WEST)
The Midcontinent Independent System Operator, covering 15 states, foresees a 4,000 MW reduction in solar capacity during the eclipse, followed by a 3,000 MW rebound. While this may pose ramping challenges, MISO plans to increase reserve requirements and line up extra generation resources.
ISO NEW ENGLAND
ISO New England estimates a potential 92% loss of solar generation during the eclipse, translating to around 6,000 MW of solar power going offline. The grid operator plans to replace solar with alternative resources like batteries and pumped storage to meet demand.
NYISO (NEW YORK)
New York’s Independent System Operator projects a drop from 3,500 MW to 300 MW in solar production at the start of the eclipse, followed by a rise to about 2,000 MW. To account for this loss, NYISO is ensuring additional resources are available to maintain grid stability.
PJM (PARTS OF NORTHEAST, MIDWEST AND SOUTH)
PJM, covering 13 states, anticipates an 85-100% reduction in solar production during the eclipse, preparing for a decrease of 4,800 MW from its solar fleet. The grid operator is deferring maintenance and keeping hydropower resources on standby.
CAISO (CALIFORNIA)
California’s grid-scale solar generation is expected to decrease by 6,349 MW to 7,123 MW during the eclipse. To counter this, the California Independent System Operator plans to ensure the availability of natural gas and hydropower resources while potentially restricting routine maintenance.
