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Distributed Energy Resources

Grids Remained Stable During Recent Solar Eclipse

U.S. power grids remained stable on Oct. 14 during a solar eclipse that occurred that day.

The California ISO reported that the eclipse ended in the late morning hours of Oct. 14 and the grid remained stable throughout. The ISO has fully resumed normal system operations.

Prior to the eclipse, the grid operator said that the eclipse would impact both grid-connected and behind-the-meter rooftop solar generation in the California ISO balancing authority and its real-time Western Energy Imbalance Market.

“With the electricity grids in the West more interconnected than ever, the CAISO has studied the potential effects of widespread solar generation loss during the three-hour eclipse, identifying risks and solutions, and coordinating with WEIM participants, the Reliability Coordinator West, and other balancing authorities and stakeholders to maintain grid reliability,” it noted.

Meanwhile, the Electric Reliability Council of Texas said it experienced no grid reliability issues during the eclipse. 

ERCOT’s Solar Power Production-Hourly Averaged Actual and Forecasted Values page offers additional data on solar generation during the eclipse on October 14.

The PJM Interconnection also confirmed to Public Power Current that there were no operational issues tied to the eclipse.

Prior to the eclipse, it simulated the possible reduction of solar resources in areas of its footprint to the south and west that were closest to the path of the eclipse in order to determine if any adjustments were needed to be made to PJM’s operations on Oct. 14.

PJM said it was also prepared to schedule and deploy additional generation and regulation resources, if necessary, to account for possible shifts in load.

On April 8, 2024, another solar eclipse will impact PJM more directly, traversing through the western reaches of the PJM footprint. PJM does not anticipate any reliability issues as a result of the 2024 eclipse, it said.