Energy Services Benefit Members & Customers

Our System Operations and Energy Services divisions work with ACES, our energy management partner, to provide:

  • Sophisticated transmission
  • Scheduling and trading services (To our Members and customers at competitive rates)

We carefully evaluate new service proposals to ensure they are a win-win for both current and prospective Members and customers. For more information, visit Our Members & Customers page.

Katie Hardman, power supply engineer, left, and Tara Davis, Member/customer services liaison, evaluate which energy imbalance market would best serve AzGT Members. See more about the EIM at Meeting Member Needs.

The ACES West Regional Trading Center:

  • Operates out of Arizona G&T’s (AzGT) Benson Campus
  • Has attracted a number of new customers

The increased scale:

  • Maximizes efficiencies and economies
  • Benefits all Members and customers
  • Helps us offer options and flexibility to meet individual needs

AEPCO’s Energy Services Department (ES) is responsible for a variety of functions.

Energy Schedules

Our ES team partners with ACES to access:

  • Nationwide scheduling
  • Trading expertise

To assure that AEPCO accounts for correct values in our AEPCO-developed Billing Unit Program (BUP), we confirm energy schedules in the day:

  • Ahead (Pre-schedule)
  • After the Flow (ATF) date

Energy Schedules Process

  1. We verify energy schedules with our host Balancing Area (BA), the Western Area Power Administration (WAPA)
  2. Then we hand off verification to AEPCO’s System Operations department to continue the process in the Real Time market
  3. At day’s end, schedules are sent back to ES for billing our Members and customers


ES billing administrators validate transactional and operational activity in the BUP to ensure:

  • Accuracy
  • Timeliness

Itron’s MV90 system:

  1. Calls Member and customer meters daily
  2. Uploads this interval data into the BUP

The BUP uses the energy schedule for:

  • Market sale and purchase data
  • MV90 meter data which includes generation load

The Energy schedule:

  • Allocates resources to our Members and customers
  • Makes sure loads and resources are balanced

Billing administrators:

  • Complete energy and transmission invoices
  • Process invoices received
  • Enter invoices in AEPCO’S SAP accounting system (Reports are provided to accounting on a monthly basis)

New HCC Billing System

Hourly Cost Causation (HCC), a new energy and cost assignment program was designed by:

  • Energy Services
  • AEPCO Class A Members

In every hour of the day based on need and contractual obligations, HCC aims to fairly assign each Member’s:

  • Energy
  • Fuel
  • Associated costs

HCC data inputs include:

  • Apache Station unit generation
  • Fuel burn
  • Energy sales and purchases
  • Member meter data
  • Ancillary services
  • Transmission costs
  • Metered Balancing Area considerations

We’re working toward a January 1, 2023, implementation of HCC, which will replace BUP.

Fuel Management

ES procures and manages coal supply and transportation to meet Apache Station generation needs, including:

  • The maintenance contract
  • Any leasing of AEPCO’s unit train of coal rail cars

Our fuels staff:

  • Procures environmental-compliance chemical additives
  • Markets fly ash
  • Provides coal energy cost analysis to ACES to assist with energy scheduling

On the natural gas side, ES works with ACES to:

  • Assure natural gas is delivered to Apache Station
  • Meet generation needs by reviewing natural gas invoices
  • Verify that the natural gas data that accounting uses is accurate
  • Assure transportation contracts are in place

ES approves gas invoices for payment and summarizes monthly activity for Members.

Resource & Operations Analytics

Our ES planning and analytics team researches how to:

  • Effectively operate existing power supply resources
  • Plan for future resources
  • Provide analytical support for ACES and our Members

ES power supply engineers work with Members to prepare AEPCO for the summer peak from pricing and risk perspectives to limit Member exposure. To address short-term resource needs, they study:

  • Market history
  • Forecast demand
  • Market products

We also develop:

  • Long-range planning studies to assure that power supply resources are in place
  • Plans that are continually updated to evaluate new opportunities