APS 2015 Annual Report Download - page 15

Table of Contents
Additionally, APS owns and operates more than forty small solar systems around the state. Together they have the capacity to
produce approximately 4 MW of renewable energy. This fleet of solar systems includes a 3 MW facility located at the Prescott Airport
and 1 MW of small solar in various locations across Arizona. APS has also developed solar photovoltaic distributed energy systems
installed as part of the Community Power Project in Flagstaff, Arizona. The Community Power Project, approved by the ACC on
April 1, 2010, is a pilot program through which APS owns, operates and receives energy from approximately 1 MW of solar
photovoltaic distributed energy systems located within a certain test area in Flagstaff, Arizona. Additionally, APS owns 12 MW of solar
photovoltaic systems installed across Arizona through the ACC-approved Schools and Government Program.
In December 2014, the ACC voted that it had no objection to APS implementing a 10 MWdc (approximately 8.5 MWac)
residential rooftop program. The first stage of the residential rooftop solar program, called the "Solar Partner Program", is to be 8 MW
followed by a 2 MW second stage that will only be deployed if coupled with distributed storage. Under this program, APS will own,
operate and maintain approximately 1,500 residential systems. The program will target specific distribution feeders in an effort to
maximize potential system benefits, while employing multiple "use cases" that will lead to a better understanding of the byproducts
stemming from the multitude of complex technical interactions occurring as distributed energy resources are employed on the APS grid.
Purchased Power Contracts
In addition to its own available generating capacity, APS purchases electricity under various arrangements, including long-term
contracts and purchases through short-term markets to supplement its owned or leased generation and hedge its energy requirements.
A portion of APS’s purchased power expense is netted against wholesale sales on the Consolidated Statements of Income. (See Note
16.) APS continually assesses its need for additional capacity resources to assure system reliability.
Purchased Power Capacity — APS’s purchased power capacity under long-term contracts as of December 31, 2015 is
summarized in the table below. All capacity values are based on net capacity unless otherwise noted.
Type Dates Available Capacity (MW)
Purchase Agreement (a) Year-round through June 14, 2020 60
Exchange Agreement (b) May 15 to September 15 annually through 2020 480
Tolling Agreement Year-round through May 2017 514
Tolling Agreement Summer seasons through October 2019 560
Day-Ahead Call Option Agreement Summer seasons through summer 2016 150
Demand Response Agreement (c) Summer seasons through 2024 25
Renewable Energy (d) Various 629
(a) Up to 60 MW of capacity is available; however, the amount of electricity available to APS under this agreement is based
in large part on customer demand and is adjusted annually.
(b) This is a seasonal capacity exchange agreement under which APS receives electricity during the summer peak season
(from May 15 to September 15) and APS returns a like amount of electricity during the winter season (from October 15
to February 15).
(c) The capacity under this agreement may be increased in 5 MW increments in each of 2015 and 2016 and 10 MW
increments in years 2017 through 2024, up to a maximum of 50 MW.
(d) Renewable energy purchased power agreements are described in detail below under “Current and Future Resources —
Renewable Energy Standard — Renewable Energy Portfolio.”
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