My Solar System, My Eclipse

Yesterday, here in Helena, we watched the moon slide overtop the sun until something near 93% of the sun had vanished.  At one time, the Arapaho Plains Indians thought all the celestial bodies were brothers and sisters.  When, on rare occasion, they witnessed a solar eclipse such as this, they were appalled, thinking that brother sun and sister moon might be having sex right there in the sky above them.

We had none of that here, but we also did not experience the level of darkness I expected.  At peak coverage (11:34 AM) we fell into a sort of eerie twilight—something near what you see 15 minutes before the sun is swallowed by the mountains each night.  But this twilight lacked the long shadows projecting from all things upright.

The strangest sensation was temperature. My arms and face chilled considerably as the moon blocked direct irradiation from the sun.

Mosquitoes, shunners of sunlight, emerged from a nearby field, thinking it was time for an evening meal.  I slapped a few of them silly.

Late in the afternoon, long after the eclipse, I received an email from my friend Dan.  He informed me that a mutual friend, Troy, was watching his solar PV power output during the eclipse.  The array output dropped to zero at 11:34.  That makes sense.  PV system output is directly related to the level of irradiation received from the sun.

My array reports daily output for me.  Posted is today a photograph of my solar PV array (taken two years ago) and a graph of my total power output from yesterday.  Each of bars on the graph represents average output over a 15 minute block of time.  You can see the valley in production produced by the array over the 2½ hour stretch of time the moon wiped across the face of the sun.  Though, at the bottom of the valley, 91 watts of output is shown, I assume my system fell to zero at the darkest point.

--Mitchell Hegman