Tuesday, July 14, 2009

"Sunniest" days in June?

One might assume that the most sun would shine down on our photo-voltaic array in the longer daylight periods of June, but there are other factors at work in the system to creating electricity.

Certainly the longest day of the year is the summer solstice of Jun21. However, due to the orientation and location of the array, we don't immediately benefit from the sunrise start of the day, but the sunset lingers right till the end.

Next, is the typical weatherman forecast for the summer of "hazy sunshine". There is a difference between a crystal clear day in the winter when the sky is azure blue, and the summer sunshine day when the sky is a bit brown and yellow from smog.

Finally, is the nature of the polysilicon panels. They lose efficiency when warm (about 10% between a winter and summer day).

All that said, our Derby, CT location has had abnormally cool days this summer thus far, and also abnormally high amounts of rain this summer. The latter washes debris off the panels such as accumulated pollen, but the associated clouds cause lack of sunshine.

During July, we had the system down 6 days for service, yet still have been generating more electricity from the sun than what we consume for our entire office and shop operations.

The Naugatuck River Valley is where we are located, and there are several large PV arrays here(Thule in Seymour, Basement Systems in Seymour, Honey Cell in Shelton, and BJ's in Derby). To my knowledge, we are the first manufacturer in CT that entirely operates off the sun. Since Mar23, 126% of our electricity has come from the sun.

The local paper did a story (includes photo and video) on the local trend which you can read here.