Clean Energy Commitment | APS Low-Carbon Economy Principles | Partnering for Innovation | Green Bond | Palo Verde Generating Station | Hydrogen | Renewable Portfolio | Energy Storage | Coal Reduction | Carbon & Air Emissions | Sustainable Fleet | Sustainable Facilities

Updated: March 2021

Our Commitment: 100% Clean Energy by 2050

Our customers and stakeholders want clean energy, and we are listening. Together, we are advancing Arizona’s clean energy future. We plan to achieve a fully clean, carbon–free energy mix by 2050 to ensure Arizona remains a healthy and beautiful place to live and work.

We've set a bold, three-part goal to provide a clean energy future for our customers:

  • An aspirational goal to provide 100% clean, carbon-free electricity by 2050
  • A nearer-term 2030 target of achieving a resource mix that is 65% clean energy, with 45% of our generation portfolio coming from renewable energy
  • A commitment to end all coal-fired generation by 2031, seven years sooner than previously projected

Carbon Goal

Our clean energy plan will be guided by sound science and focused on achieving environmental and economic gains—all while maintaining affordable, reliable service for our customers.

Collaboration with customers, regulators and other stakeholders is key to our plan’s ultimate success. We look forward to working alongside those who believe in this vision to move forward together to keep Arizona clean, beautiful and thriving.

“We see incredible things ahead for Arizona and are excited to power our state’s future with electricity that will be 100% clean.” — Jeff Guldner, Chairman and CEO, Arizona Public Service

Pathways to 100%

In 2020, we made great progress toward our vision for a carbon-free energy future;  

Steady production of carbon-free nuclear power from Palo Verde Generating Station – The station continued to do its part, producing clean nuclear power with a 91.2% capacity factor (an important measure of efficiency) for the year and at 100% during the hottest Arizona summer on record. This production pushed Palo Verde’s lifetime output to more than a billion megawatt-hours – the only nuclear power plant to surpass that milestone.  

Adding more clean resources to meet customers’ growing energy needs – APS secured more than 400 megawatts of clean energy resources, including 200 megawatts of wind power and 75 megawatts of demand response capability. APS also issued a request for proposal in late 2020 to acquire more battery storage that can be combined with solar generation to add between 1 and 1.5 gigawatts of new resources to the system, including more renewable energy. APS also recently executed an agreement with Invenergy to add battery energy storage to six APS solar plants located in Maricopa County and Yuma County. These systems will begin operation in early 2022.

Planning a responsible transition from coal – To facilitate the shift  from coal, APS proposed a coal communities transition plan to support the areas that are home to coal-fired power stations. If approved by the Arizona Corporation Commission, the $144 million package would help communities surrounding the Four Corners and Cholla power plants, including the Navajo and Hopi nations, to diversify and modernize their economies. 

Providing energy efficiency tools and programs to help customers conserve electricity – Energy saved is considered clean energy for the production and associated emissions it avoids. Among the company’s many energy-efficiency programs for  residential and business customers, APS distributed more than 10,000 Google Nest Thermostats (valued at $129 each) to customers when they enrolled in APS Cool Rewards. In partnership with CPower, APS also expanded the Peak Solutions program to more commercial and industrial customers who can enroll in voluntary conservation measures when demand for energy peaks on the APS system. This program helped APS maintain a stable supply of electricity through record heat in the summer of 2020.

Going beyond the generation mix to help reduce emissions in other sectors – With 34,000 electric vehicles already on Arizona’s roads, easy access to charging stations may entice even more drivers to go electric. Through the Take Charge AZ pilot program, APS covers the cost of installing and maintaining equipment for Level 2 charging stations at businesses, government agencies, non-profits and multifamily communities. At year-end 2020, 84 charging stations were installed through this pilot. The goal is to have 200 to 400 Level 2 ports across APS service territory by the end of 2021. Now, through a new APS partnership with Electrify America, more charging infrastructure will help make for a reliable EV experience on longer trips.   

APS Low-Carbon Economy Principles

APS's transition to clean energy will contribute to a future low-carbon economy that will create new growth opportunities while providing environmental benefits. APS developed a set of principles to guide our path toward a low-carbon economy.

Read the APS Low-Carbon Principles.

Partnering for Innovation

Achieving our clean energy commitment will require continued advances in energy technology. To help drive clean energy investment and innovation, APS will encourage policies that enable market–based solutions and serve as a driving force behind energy research and development. APS will continue to pursue the advancement of new and emerging technologies. Given the research, incubator labs, startups and investment involved in clean energy, we are confident emerging technologies will become proven and commercially available at competitive prices. Some recent partnerships include:

Partnership to find customer solutions: We are collaborating with Advanced Energy Economy  to develop solutions to help APS achieve our ambitious goals for clean energy and support electrification of the transportation sector. Learn more about some of the solutions proposed.

Statewide Transportation Electrification Plan: APS engaged in a collaborative stakeholder process to develop a statewide transportation electrification strategy and plan. Stakeholders have participated in five working groups to understand the electric transportation market, technology, policy and trends. The plan is expected to be completed in the first half of 2021.

Partnership with industry experts: APS became a partner in the Low-Carbon Resources Initiative (LCRI). The LCRI is a unique effort across the energy landscape, leveraging the collaborative research models of Electric Power Research Institute (EPRI) and Gas Technology Institute (GTI) to produce industry-leading results for society. This five-year initiative brings together industry stakeholders to accelerate development and demonstration of low- and zero-carbon energy technologies through transformative, clean energy research and development.

Learn more about our Customer Technology Solutions.

Green Bond

A green bond is a type of fixed-income instrument with proceeds allocated to fund projects with environmental benefits. APS issued its inaugural green bond in September 2020. Through this offering, we issued $400 million, which can be used to support projects such as renewable generation, energy storage, energy efficiency programs, climate change mitigation and clean transportation.

Learn more about our green bond and expenditures.

Palo Verde Generating Station

Palo Verde Generating Station has been the nation’s largest power producer of any kind for nearly 30 years – all of it clean and carbon-free. As the heart of the APS generation fleet, it provides the foundation for the reliable service our customers know they can count on.

The plant is a critical asset to the Southwest, generating more than 32 million megawatt-hours annually – enough power for more than 4 million people.

Palo Verde produced its billionth megawatt-hour of clean electricity in 2020, in addition to operating at a capacity factor of 100 percent from June through September, which was critical to providing reliable service to our customers during the hottest summer on record.

Nuclear energy works with renewable generation to create a more reliable, diverse clean energy portfolio. Because Palo Verde is producing clean energy at all hours supporting the basic electrical needs of our customers when solar and wind are not available. Without nuclear energy, carbon emissions would increase due to a greater reliance on carbon-emitting fossil fuels to fill the inevitable energy void during periods of low renewable generations, such as after sunset. Nuclear energy can facilitate increased adoption of electric vehicles (EVs) and improve the environment by supplying zero-emission energy to charge EVs and large-scale batteries.

While Palo Verde has seven owners in four states, nearly half of its output is dedicated to serving Arizona consumers. Electricity generated by the plant annually displaces more than 13.3 million metric tons of greenhouse gas (GHG) emissions that otherwise would have been produced, providing clean energy that powers about four million homes and businesses throughout the Southwest.

Additionally, as the nation’s only nuclear plant not located on a body of water, Palo Verde recycles more than 20 billion gallons of wastewater annually from surrounding municipalities to cool the plant.

Learn more in our section on Water.

Learn more about Palo Verde Generating Station at and


Achieving our clean energy commitment will require continued advances in energy technology. One of the more promising emerging opportunities is the use of hydrogen. A substantial majority of the world’s industrially produced hydrogen creates carbon dioxide as a byproduct. However, when hydrogen is produced by electrolysis using clean electricity (such as nuclear, solar or wind energy), the resulting hydrogen is carbon-free. Producing hydrogen when there is an excess of carbon-free electricity creates an energy vector that can be used as another clean energy storage technology for meeting peak demand. The clean hydrogen can also be used as an energy carrier for evolving hydrogen transportation technologies, and as a feedstock for the production of synthetic hydrocarbons that introduce no new carbon into the environment.

Innovative Hydrogen Partnership. APS is one of three utilities chosen by the Department of Energy's Office of Nuclear Energy to participate in a hydrogen production project in partnership with Idaho National Laboratory. The goal is to improve the long-term economic competitiveness of the nuclear power industry through the integration of hybrid energy systems such as hydrogen production. The multi-phase project, planned for 2020 through 2023, will examine how hydrogen can be produced by clean nuclear power. Experience from the pilot project will offer insights into methods for flexible transitions between electricity and hydrogen generation missions in solar-dominated electricity markets and demonstrate how hydrogen may be used as energy storage to provide electricity during operating periods when solar is not available.

Learn more about the Palo Verde & Idaho National Lab hydrogen partnership

Renewable Portfolio

APS has a diverse portfolio of existing and planned renewable resources totaling 2,106 MW, including solar, wind, geothermal, biomass and biogas. Of this portfolio, 1,956 MW are currently in operation and 150 MW are under contract for development or are under construction. Renewable resources in operation include 245 MW of facilities owned by APS, 626 MW of long-term purchased power agreements, and an estimated 1,085 MW of customer-sited, third-party owned distributed energy resources.

APS’s strategy to achieve its RES requirements includes executing purchased power contracts for new facilities, ongoing development of distributed energy resources and procurement of new facilities to be owned by APS.

APS also issued two RFPs in September 2019. The first RFP sought competitive proposals for up to 150 MW of APS-owned solar resources. This solar generation will be designed with the flexibility to add energy storage as a future option. A second RFP requested up to 250 MW of wind resources to be in service as soon as possible, but no later than 2022. As a result of this RFP, APS executed a 200 MW power purchase agreement for a wind resource that is expected to be in service in the fourth quarter of 2021. In December 2020, APS issued two additional RFPs: one to acquire both renewable energy and additional peaking capacity resources, and the other to install more battery energy storage at two existing APS solar plants.





Energy Storage

APS deploys several advanced technologies on its system, including energy storage. Storage can provide capacity, improve power quality, be utilized for system regulation, integrate renewable generation, and, in certain circumstances, be used to defer certain traditional infrastructure investments. Energy storage can also aid in integrating higher levels of renewables by storing excess energy when system demand is low and renewable production is high and then releasing the stored energy during peak demand hours later in the day and after sunset. APS is utilizing grid-scale energy storage projects to benefit customers, to increase renewable utilization, and to further our understanding of how storage works with other advanced technologies and the grid. We are preparing for additional energy storage in the future.

We plan to install at least 850 MW of energy storage by 2025, which includes 150 MW of energy storage projects under power purchase agreements (“PPAs”) and 141 MW of AZ Sun Phase I retrofits. The remaining energy storage is expected to be made up of resources solicited through current and future RFPs. In the first half of 2021, APS has two RFPs in the market that seek energy storage resources: (i) a battery storage RFP for projects to be located at the remaining two AZ Sun sites that were not included in the 2018 RFP; and (ii) an ‘all source’ RFP that solicits both standalone energy storage and renewable energy plus energy storage resources. Such resources would be expected to be in service during 2023 and 2024.requirements.

Learn more about our energy storage strategy at 

Coal Reduction

We have retired over 1,000 megawatts of coal-fired electric generating capacity. These closures, in addition to other measures taken by APS, have resulted in a reduction of carbon emissions of 33% since 2005, which is equivalent to removing more than 1.16 million passenger vehicles from the road. In addition, we have committed to end the use of coal at our remaining Cholla units by 2025 and made an overall commitment to exit coal by 2031, which means we will close the Four Corners Power Plant seven years earlier than our original plan.

With plant closures, we work closely with impacted employees and local communities to ease the transition and support long–term economic planning for a future beyond coal.

Learn more about our coal communities transition plan.

Carbon & Air Emissions

In 2020, APS carbon dioxide emissions were 12,288,309 US tons. This represents a 33% decrease in annual carbon dioxide emissions since 2005. Since 2005, we have also achieved reductions of 85% for NOx and 89% for SO2 from our overall fleet. This resulted from our commitments to reduce emissions and institute operational efficiency enhancements.

Learn more about our air emissions data.

CDP Recognition. We believe it is important to disclose our carbon management strategies and GHG emissions to customers, investors and other stakeholders. Through significant demonstrable action on climate change risk, Pinnacle West is leading on corporate environmental ambition, action and transparency worldwide. Pinnacle West has been recognized for leadership in corporate sustainability by global environmental non-profit CDP, securing a place on its prestigious A List in 2019 and 2020 for tackling climate change. CDP collects and analyzes environmental data and benchmarks companies for investors to use in financial decisions. CDP’s network of investors represents more than $106 trillion in assets.

In 2020, Pinnacle West was the only U.S. electric utility to earn an A score for Climate and the only U.S. electric utility to earn A scores in  the Climate and Water categories. We were recognized for our actions to cut emissions, mitigate climate risks and contribute to a low-carbon economy. Our scope 1, 2 and some of scope 3 GHG emissions reported to CDP are third-party verified

In addition, we submit a comprehensive annual report of our GHG emissions to the Environmental Protection Agency (EPA) as required by federal law.

Read our news story and learn more about our CDP responses and documents.

Sustainable Fleet

In July 2020, we set a goal of transitioning 30% of our light-duty vehicles and equipment (comprised of forklifts, all-terrain vehicles, golf carts and light-duty passenger vehicles) to electric by 2025 with an aspirational goal of achieving a 100% clean, carbon-free fleet by 2050.

Our transportation fleet’s conversion to more fuel-efficient vehicles and electrification continues through market research and updates to our electrification strategy. We are monitoring medium and heavy-duty options and will adopt them once there is more commercial availability. Through this ongoing conversion and by using our fleet more efficiently, we are working to reduce carbon emissions and operating costs.

APS has also adopted idle-mitigation technology as part of a standard package offered on all trouble trucks, allowing workers to run laptops and air conditioning without keeping the vehicle running. In addition to reducing our carbon footprint, this decreases noise when working in residential neighborhoods. Our Odyne bucket trucks use less fuel and have quieter operations than traditional diesel or gasoline engine trucks by using battery-assisted drivetrain and electric power takeoff (ePTO) technology while operating the bucket. We are currently evaluating the new idle-mitigation technology for adoption in our larger trucks.

Sustainable Facilities

Our commitment to reduce our environmental footprint through sustainable practices is evident throughout our APS occupied facilities. Over the past 12 years, APS has achieved 14 Energy Star labels across our building portfolio, including two last year at our Corporate Headquarters and Paradise Valley Service Center. Sustainability strategies are embedded within our standard architectural and engineering specifications when managing changes to our buildings or constructing new space. We work to improve energy efficiency throughout our facilities by replacing obsolete building systems and equipment with more energy-efficient systems and equipment. 

While sustainable solutions are integrated into our sustainability efforts, we are also ‘designing for tomorrow’ through the implementation of our Workplace of the Future initiative. This effort  increases the efficiency of how we use space and enables greater flexibility to support the evolving needs of our business and employees. The first full floor renovation was completed in 2020 allowing our IT organization to accommodate 112% more people assigned to the floor (231 up from 109). The project included a combination of working, meeting and collaboration areas that bring people together in an energizing, engaging, employee-centric atmosphere. The design incorporated many sustainable elements including the use of natural lighting, daylight harvesting, LED lighting fixtures, more efficient HVAC systems, a more robust trash recycling program and sustainably sourced furniture. Once we can safely return to the office, we will monitor and measure the effectiveness of the implemented strategies and incorporate what we learn into future projects.

To further reduce carbon emissions from employee vehicles, APS deployed 28 employee vehicle charging stations in 2020, an increase of over 250% in charging capacity for our employees. The company plans to roll out 80 new charging stations for employees across the state over the next five years.

Going forward, along with our Workplace of the Future effort, proactive assessments of the health and use of our buildings, utilization of the most current technologies as we renovate, reusing materials where possible and further replacing ozone-depleting technologies will guide our decision-making. We will continue to design, construct, operate and maintain our new and remodeled facilities to ENERGY STAR standards and LEED principles.



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