Mar 9, 2015

View from Solar House in Adams Morgan

The other day, I went over to a friend's house for a solar visit. After brunch, I climbed onto the roof and took a video of her solar installation. It was a great view--just at the corner at Cliffbourne Place and Biltmore Street NW in Adams Morgan. 

In the video, you'll see 12 panels. These are manufactured by Evergreen Solar (see note below) and have a combined power capacity of 2.28 kw or 190 watts per panel.

You'll also notice a solar array on a neighboring roof. It's a virtuous cycle--once you've made it onto one roof in an area, you spot 10 more roofs to visit. Making that initial breakthrough is the toughest part.

Although this is a nice high roof, there are a couple of problems. First, there is a lot of shade from chimneys and heating-ventilation units.  When a shadow is cast on one panel, it affects the output of an entire row of panels. Here's a good explanation of shadows on panels:
  • You can think of a string of panels as something like a piece of pipe, and the solar power is like water flowing through that pipe. In conventional solar panel strings, shade is something that blocks that flow. If, for example, shade from a tree or a chimney is cast on even one of the panels in the string, the output of the entire string will be reduced to virtually zero for as long as the shadow sits there (Solar Choice Blog).
A second problem is that the roof is slanted toward the west--southern exposure would be ideal. Most row houses in DC have slanted roofs and if you're on the south side of an east-west street, you'll be slanted south. Lucky you.

Note: Evergreen Solar filed for chapter 11 bankruptcy in August 2011. It was a darling in Massachusetts but production costs were too high (CNET Magazine). Four years ago, this failure (800 jobs lost) along with others made the industry look bleak. A very different landscape from today's.

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