Distributed Renewable Energy Operating Impacts and Valuation Study

Technical Value – Distribution System
Table 3-15
Demand Reduction Due to Daylighting
for Commercial Applications
Customer Type
Peak Demand Reduction
Grocery 0% - 9%
School 0% - 5%
Warehouse 0% - 2.5%
Large Retail 0% - 0.5%
Results indicate that, while daylighting is a good source of energy reduction for the customer, it
has little impact on peak demand.
Feeder and Substation Analysis
As mentioned previously, the Study team conducted an analysis of demand reduction associated
with solar DE at the feeder and substation level to determine the potential for reduction in
distribution equipment sizing. This analysis was conducted at a screening level, as well as a
more detailed model (EPRI’s DSS Model).
Screening Level
Screening analysis of feeders and substations was performed by modeling increasing levels of
PV and SHW capacity ranging from 15 percent to 60 percent of feeder load. In other words, the
base level of installed capacity for each type of solar DE deployed is equivalent to 15 percent of
the feeder peak, or 15 percent penetration. Figure 3-7 shows the demand savings of three feeders
at the Chaparral Substation in the East Valley. The annual energy and peak demand of each
feeder is indicated in the legend. Each feeder is modeled with the following types of solar DE
individually:
• Single-axis tracking PV (Tracking)
• South-facing fixed PV (S-Fixed)
The graph indicates the variance between the feeders and, in some cases, between the solar
orientations. Similar to the analysis conducted for specific residential customers, the lines in the
figure below represent one or more specific feeder. The results varied widely depending on the
hourly demand characteristics of the customer types located on the feeder. For example, the
single axis tracking demand savings held steady at approximately 4 percent for one feeder type,
but ranged from approximately 9 percent to 15 percent for another feeder type. The analysis
reveals that at the feeder level, the maximum demand reduction is approximately 15 percent
reduction, even with 60 percent solar DE penetration.
Distributed Renewable Energy Operating Impacts & Valuation Study R. W. Beck, Inc. 3-25