Photo courtesy of the NASA/Bill Ingalls

As energy nerds, we were nearly as excited to browse through solar submeter data from Monday as we were to actually see the eclipse. And the Gridium team was not alone...

solar eclipse data in Snapmeter

Snapmeter charting the output from a solar PV system installed at a commercial real estate building 500 miles from the path of totality, experiencing 75% of the eclipse.

It’s no surprise that–thanks to the solar eclipse on Monday–total solar power production in California dropped 16.2% (compared to Tuesday). What was surprising, for energy traders and the grid operators who had spent more than a year preparing for the #apocaclipse, was the 3.8% drop in total energy demand on the day.

California ISO solar data

California ISO Renewables Watch data show not only a drop in solar energy production, but also a drop in total system demand at the time of the eclipse.

This meant more than some new shapes on load curves across the country, it also meant many energy traders lost money on long price bets. Indeed, spot power prices in California went negative, and dipped in New York as well as Texas. Given the drop in demand during the eclipse period, spot prices were about half of what grid operators had paid in the day-ahead market for supply. Once the moon moved out of the way, solar production ramped up and sent prices even lower.

For our building operators with a long view of their BMS scripts, the next total solar eclipse in North America will sweep across the country on April 8, 2024. And if you need to monitor any generating assets in the building, send us your submeter data!

About Millen Paschich

Millen has been thinking about the built environment since he was four, when he started with site walks on residential construction projects. He began his career at Cambridge Associates and has an MBA from UCLA. Talk to him about bicycling, buildings, businesses, and green chile burritos!

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