Monday, August 25, 2014

Are These Solar Panels on A Brooklyn Building A Benefit or Bling?

© Manon Verchot
There are optimal angles for the setting of solar panels. That's why they are usually put on roofs, not facades.

Diane Pham of New York real estate website 6Sqft shows an interesting new project in Brooklyn with a façade that is dominated by a massive solar panel. She notes that "while the PV panels without question make the building stand out, they’re not quite positioned for optimal sun exposure, ultimately making the addition more of a really expensive ornament than a true measure for sustainability."

© Google Maps
It's an interesting point. This is supposedly a 7 kw array, but solar panels usually face due south (although some are now recommending that they should face west; these are sort of SSW). There are apartment buildings across the street that are as high or higher than this building, so there is a real question about how much sun they will get in winter (although we took our photos in the morning and 6sqft took theirs in the afternoon, and they both show full sun on the panels). So you have a high angle of incidence with the high summer sun, reducing output, and you probably have lots of shading in winter.

© Manon Verchot
Diane also points out that covering the wall with a panel like this reduces the opportunity for passive solar gain in winter, although it does provide significant shading in summer, reducing air conditioning load, which is probably a bigger issue.

© McMahon Studio
Given the lousy angles and possible shading, one has to wonder what size of a tracking rooftop array would give the same amount of juice. Then you wouldn't be so obviously shouting "look at me, I'm green!" But let's be charitable here, marketing is important too. The architect's website has a whole section devoted to (horizontal) solar panel installations he knows what he is doing here. And we should applaud Jeffrey McMahon and Amiel Savaldi for trying to build (and market) a better, greener building. Not a lot of developers are.


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