Page 33 - Zero Net Energy Case Study Buildings-Volume 2

CASE STUDY NO. 7 DPR CONSTRUCTION OFFICE BUILDING
Two additional contextual factors affected the final design of the roof and the amount of PV panel area that could be installed there. The first was DPR’s desire not to allow the PV panel arrays to become a visual distraction from the form and character of the original warehouse building. The second was a desire by DPR not to block sunlight and views from the middle floor of the neighboring five-story building to the north, even though zoning regulations would have allowed this. These factors resulted in a mostly horizontal orientation for most panels, hugging the roof form. One part of the array actually faces east at a slight tilt, where the roof rounds down toward the street façade in that location.
As is the case with standard solar photovoltaic panel installations, only a few percentage points in performance are lost for a horizontal installation as opposed to an optimum performance tilted array. Since panels in horizontal arrays do not cast shadows on adjacent panels in that array, the number of panels that can be fit on to an urban roof is maximized. This delivers more power in general (kW) from the system despite the small loss in efficiency due to panel orientation.
Zero Net Energy Case Study Buildings, Volume 2
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PHOTO: TED VAN DER LINDEN