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Arizona Energy Policy Simulator

The Arizona Energy Policy Simulator (EPS) is a free and open-source computer model created by Energy Innovation LLC and RMI. It is adapted from software originally created by Energy Innovation LLC.

Run the simulator in your browser

U.S. State EPS Methodology​

The U.S. State EPS Methodology page details our basic modeling assumptions, data sources, and methodology by sector. Additionally, we include information on the business-as-usual (BAU) and nationally determined contribution (NDC) scenario assumptions.

Acknowledgement of Contributors and Reviewers​

We would like to acknowledge the following people who made the U.S. State Energy Policy Simulators possible.

  • Olivia Ashmoore, Energy Innovation LLC
  • Megan Mahajan, Energy Innovation LLC
  • Dan O'Brien, Energy Innovation LLC
  • Robbie Orvis, Energy Innovation LLC
  • Wendy Jaglom, RMI
  • Kayleigh Rubin, RMI
  • Addy Sonaike, RMI
  • Drew Veysey, RMI

Version History​

4.0.6 - October 2, 2026​

  • New Features
    • Updated to 4.0.6 EPS model platform (includes all 4.0.5 platform changes; see the U.S. model version history)
  • Data updates
    • Updates all input data to the latest available version from data sources, including EIA SEDS 2024, EIA Forms 860 and 923 for 2024, and the EPA state greenhouse gas inventory
    • Recalibrates forecasts to the EIA Annual Energy Outlook 2026
    • Updates first modeled year to 2025, all policy implementation schedules to start in 2026, and output currency year to 2025
    • Updates BAU to reflect the latest federal policy changes, including the One Big Beautiful Bill Act, EPA rule changes, and withdrawal of state zero-emission vehicle standard waivers
    • Updates state-level policies in the BAU scenario, including clean electricity and renewable portfolio standards, energy storage targets, coal retirements, building and appliance standards, oil and gas methane rules, electric vehicle rebates, and carbon pricing programs (see documentation)
    • Updates existing capacity, planned capacity additions, and coal retirements to latest EIA data
    • Adds state-specific renewable resource limits and build rates based on NREL supply curves
    • Adds data center electricity demand as part of BAU load
    • Updates distributed solar capacity and adds behind-the-meter gas generation
    • Updates vehicle stocks and electric vehicle adoption to latest state registration and sales data
    • Updates process emissions and abatement costs to the EPA July 2025 non-CO2 report

4.0.4 - April 1, 2025​

  • New Features
    • Updated to 4.0.4 EPS model platform
    • Adds a 'Federal Policy Repeal and Rollback' scenario to model the repeal of the Inflation Reduction Act and select EPA rules affecting greenhouse gas emissions
  • Data updates
    • Updates calculations for BAU vehicle tax credits
    • Fixes to BAU clean electricity tax credit calculations and CCS tax credit calculations
    • Updates all policy implementation schedules to start in 2025
    • Updates output currency year to 2024
    • Recalibrates the share of costs that to be covered to be considered profitable and capacity supply curves for the electricity sector
    • Updates BAU planned capacity additions to use latest EIA data on plants that have received regulatory approval
    • Updates natural gas prices based on latest gas futures data
    • Updates government revenue accounting settings to use deficit spending for all government cash flow types
    • Updates to capacity factors for new onshore wind
    • Changes the repayment period for capacity market changes to 3 years
    • Updates transmission construction costs to exlucde spur line costs, which are captured separately
    • Updates input-output data to use values from the Economic Census for some states and sectors
    • Fixes mistake in process emissions file to calculate methane emissions

4.0.2 - September 17, 2024​

  • Updated to 4.0.2 EPS model platform
  • Data Updates
    • Updated BAU to reflect components of the Inflation Reduction Act and latest EPA rules (see documentation)
    • Updated input data to the latest available version from data sources, including the U.S. Energy Information Administration and the U.S. Environmental Protection Agency

3.4.3.3 - June 9, 2023​

  • Bug fix
    • Prevent rare Vensim error caused by negative ppriority values in ALLOCATE AVAILABLE function

3.4.3.2 - May 19, 2023​

  • Bug fix
    • Allow changes in capacity construction subsidies to affect electricity prices

3.4.3.1 - February 6, 2023​

  • Official launch of the U.S. State Energy Policy Simulators

Model Download​

The Arizona Energy Policy Simulator may be used on this website through your web browser, or the full version may be downloaded to your computer by clicking the button below. Note that you will need to go through the steps explained on the EPS download page in order to install the required software and make use of the downloadable version of the model.

Download the Arizona Energy Policy Simulator

Software License​

The Energy Policy Simulator (EPS) is released under the GNU General Public License version 3 (GPLv3) or any later version and is free and open-source software. Refer to the Software License page for full details.

Image Credits​

Horseshoe Bend, Arizona
Loren Cutler
https://unsplash.com/photos/Km9IZ3JawGc
License: Unsplash License
Changes: Image has been cropped and a fade has been applied to the left side.