358 Energy Project Financing: Resources and Strategies for Success
- Due to a change in occupancy patterns planned to take effect
about the same time as the ECM installation, it is assumed that the
load/duration profile in the post-retrofit period will be as shown
below:
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Stipulated Post-retrofit Load/Duration
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Fraction of Lighting Load On Hours Per Year
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9% 240
61% 2,000
15% 2,500
6% 6,100
9% 8,760
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- Measurements were made with a recently calibrated RMS power
meter of the three phase power draw on the 277 volt lighting
circuits. The manufacturer’s rating on this power meter is ±2%
of full scale and readings were roughly 50% of full scale. From
a thirty second measurement on the input side of two lighting
transformers, it was found that with all fixtures switched on, the
total power draw was 28.8 kW, though 7 lamps (= 0.3 kW or 1%)
were burned out at the time of the test. It was determined that the
fraction burned out at the time of this measurement was normal. - The electrical demand for lighting was assumed to be equal to the
measured circuit load for ten months of the year when school is
in session. This stipulation may be in error by no more than 3%
since lighting is the dominant electrical load of the building. Based
on the utility bills showing a demand reduction during July and
August, the minimal use of the facility during these months, and
the other equipment used during the summer, it was assumed that
the July and August lighting circuit demand is only 5 0% of the
measured circuit load. - The possible errors in the above stipulated post-retrofit lighting
load/duration profile are: