Distributed Renewable Energy Operating Impacts and Valuation Study

Executive Summary
Capital Cost Reductions at Generation Level (2008 $000)
Medium Penetration Case
Generation
System
Carrying Charge
(%)
Associated
Annual Savings
2010 $0 11.79% $0
2015 $0 11.79% $0
2025 $184,581 11.79% $21,762
High Penetration Case
2010 $0 11.79% $0
2015 $0 11.79% $0
2025 $299,002 11.79% $35,252
Much of the potential annual saving from solar DE production results from APS avoiding the
need to produce that same energy from conventional sources. This reduced energy requirement
decreases fuel and purchased power requirements and brings associated reductions in line losses
and annual fixed O&M costs. Generally, these energy savings were found to exist for all
deployment cases, with the exception of reduction in fixed O&M costs for the Low Penetration
Case. Additionally, unlike certain capital deferrals, the specific location of the deployment of
solar DE was not a determinant for these value characteristics.
The values determined for the annual energy savings (including the reduction in losses discussed
in Section 4 and the reduction in fuel and purchased power costs discussed in Section 5) are
shown in the table below and are a direct result of the output from the solar DE installations. As
more solar DE technology is installed, these savings values will directly increase. Reductions in
fixed O&M costs related to the reduction in demand for the dependable generating capacity. The
Target scenario results are identical to the High Penetration Case (as the Target scenario is
focused on specific locations of solar DE on the distribution system, which impacts the capacity
savings, but not the energy savings). The single-axis sensitivity shows a slightly higher energy
savings resulting from increased production from these units. The energy value assessment is
more fully discussed in Section 5.
xx R. W. Beck, Inc.
Arizona Public Service