ERCOT Night-time Solar

We're past 2010 (Space Odyssey), so it can't be aliens.

Solar Deliveries At Night

Back in October, an anomaly in the solar deliveries caught my eye. All of a sudden, there was a notable amount of solar power delivered in the overnight. This of course requires energy storage (unless Jupiter has become a star which, so far, and despite Arthur C. Clarke’s fantasy prediction, it hasn’t), and storage can definitely have a place in ERCOT if the price is right.

Solar dispatch in October, 2021. The appearance of a “large” night-time delivery sticks out in the data. Blue points are the 5-minute values while the green areas are the “future” forecast as of the forecast date.

We mentioned this “dramatic” new feature of the solar dispatch at the time, but we were expecting it to continue stronger into the future—which it didn’t. There have been other instances of this, namely in late January of this year which is plotted here, but mainly, these night-time dispatches have been few and far between.

ERCOT solar dispatch with forecast. Yellow area is the hourly dispatch. Blue dots are the 5-minute solar value, and the green areas are the forecast for the give date in the title.

Note the blue dots which represent the published 5-minute values differ with the hourly values in this latter episode. This was not true in the October, 2021 event. It could be that the interpretation is that the hourly values are just wrong. For some points in the past, that is possible, including this one, but the newer data as of 2022 would suggest otherwise.