Naturally, I wanted to see what kind of data was available, and it turns out the power output is recorded every 15 minutes, even during the night (who knows -- maybe we'll get some power from the sunlight reflected by a full moon or from a passing comet). The output is measured separately for two halves of the farm called Array A and Array B. You can see the arrays, along with the sheep that maintain the grass at the solar farm, in the photo below.
Here's a graph of both arrays for the few sunny days in April we had here in Cary, North Carolina. I used the Data Filter to include only the sunny days and modified the axes to show only the daylight hours.
The flatness of the power output curve is a testament to the sun-tracking rotation of the panels. They're on a horizontal axis that runs north-south, and so can turn toward east or west.
Two interesting features stand out:
There's a dip in the outputs around midday.
Array A lags Array B in the early morning.
I think I know why these things are happening. But what do you think the reasons are?
In case you want to explore the solar farm data from April, it's available in the JMP File Exchange (scroll down to the bottom of the page to find the solar farm file).