I am in Toronto and we only had a partial eclipse but I am guessing that it cost me about 7kWh of generation today. My generation curve normally looks like a Gaussian distribution but it has a big downward kink in the early afternoon.
I lost 6-7 kWh or 8-10% (from a 13.4 kW array) compared to a recent full-sun day. We are in Northern California, 80% eclipse, and I lost 83% of wattage at 10:17 AM (max eclipse) compared to the sunny day.
I live 60 miles South of Los Angeles, 755 miles from the center line of the eclipse. I calculated my loss was 3.1 kWh. Cleared just an hour before eclipse. My system is 6.3 kW. A loss of 7.8% for an expected 39.6 kWh.
Checking zip codes, I found this PVoutput member in Beaverton, OR… Output dropped to 15 watts at max eclipse. Beaverton was just outside the “totality” path with a 99.6% eclipse.
I’m at Lake Tahoe, Northern California.
I dropped from 3471 W peak at 9:10 am to 793 W at 10:20 and recovered to 4938 W at 11:50
Generation for the day was down about 5 kWh.
Interesting replies. I hadn’t thought of this before but the losses would be larger for folks in the midwest and east where the eclipse occurred around noon, rather than the west coast where the eclipse occurred early in the morning as the “notch” carved by the eclipse would come out of the top of your daily curve rather than the upslope on the left. Look at that curve from the Beaverton, Oregon system and roll it forward a couple of hours and the losses would have been much more.