Page 223 - Solar Power in Building Design The Engineer's Complete Design Resource

WAREHOUSE, ROCHESTER, NEW YORK 193

The entire system consists of 35 NPS1000 Power Gateway modules from Nextek
Power Systems in Hauppauge, New York. These devices take all the available
power from the solar panels and send it directly to the lighting use without signif-
icant losses. Additional power, when needed at night or on cloudy days, is added
from the grid.
In the office, six NPS1000 Power Gateway modules power 198 four-foot T-8 fluo-
2
rescent lamps, illuminating most areas at 1.1 W/ft . Each of the fixtures is equipped
with a single high-efficiency dc ballast for every two lamps. Most of the fixtures are
controlled by a combination of manual switches, daylight sensors, and occupancy sen-
sors in 13 zones.
In the warehouse area, 29 NPS1000 Power Gateway modules power 158 six-lamp
T-8 fixtures. These fixtures have low, medium, and high settings for two-, four-, and
six-lamp type fixtures, which are dimmed by daylight, and occupancy sensors are
located throughout the area. The goal of the control architecture is to maintain a light-
2
ing level of 0.74 W/ft , using daylight when available, whenever the area is occupied.
Figures 7.6 and 7.7 depict Nextek dc power system lighting controls.

Figure 7.6 Nextek Power Systems solar power integration diagram.