Clean Energy Commitment | APS Low-Carbon Economy Principles | Palo Verde Generating Station | Solar Research & Development | Energy Storage | Coal Reduction | Carbon & Air Emissions | Sustainable Fleet | Sustainable Facilities

Our Commitment: 100 Percent Clean Energy by 2050

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

  • An aspirational goal to provide 100 percent clean, carbon-free electricity by 2050
  • A nearer-term 2030 target of achieving a resource mix that is 65 percent clean energy, with 45 percent of our 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

View a one-page summary of our clean energy commitment.
Read the related news release.

Pathways to 100 Percent Clean


Policy decisions

Support policy decisions that leverage market-based technology and innovation to attract investment in Arizona


Existing power sources

Near-term use of natural gas until technological advances are available to maintain reliable service at reasonable prices


Evolving market-based solutions

Participation in the Energy Imbalance Market provides access to clean energy resources while saving customers money



Electrification will drive a cleaner environment and more energy-efficient operations throughout the economy


Modernization of the electric grid

Continue to advance infrastructure that is responsive and resilient while providing customers more choice and control


Energy storage solutions

Storage creates opportunity to take advantage of midday solar generation and better respond to peak demand

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.

Palo Verde Generating Station

For the 27th consecutive year, Palo Verde was the nation’s largest energy producer, generating 31.1 million megawatt-hours (“MWh”) of carbon-free electricity in 2018. Palo Verde is the only generating facility in the United States to produce more than 30 million MWh in a year, a milestone the plant has achieved 10 consecutive years and a total of 14 times. APS operates the Palo Verde Generating Station and owns or leases 29.1 percent of the facility.

Palo Verde has produced more carbon-free electricity than all the solar power plants built in California, and it does so reliably at all hours. It even uses recycled wastewater to meet its cooling needs.

Nuclear energy works in concert with renewable generation. Without nuclear energy, carbon emissions would increase because of greater reliance on natural gas to fill the inevitable energy void. Because Palo Verde is producing energy at all hours – day and night – it supports the basic needs of customers when solar and wind are not available because of their intermittent nature. It can facilitate increased adoption of electric vehicles (“EVs”) and improve the environment by supplying zero-emission energy to charge EVs and large-scale batteries instead of relying on natural gas- or coal-fired power plants to do the job.

Nearly half of Palo Verde’s output is dedicated to serving Arizona consumers. Electricity generated by the plant annually displaces more than 13.2 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.

Watch to learn more about Palo Verde as a leader in clean energy:

Solar Research & Development

We are a national leader in solar energy, with more than 1.4 gigawatts of solar capacity producing energy for our customers in Arizona. Our customers can count on us for innovative solutions that will advance Arizona’s solar leadership, including ground-breaking research to evaluate how energy companies can bring the benefits of this clean, renewable resource to customers reliably, fairly and affordably. Solar is an important part of our increasingly clean, diverse energy mix that will continue to grow in the future. We are setting the course for a sustainable energy future that brings together clean energy resources including solar, advanced technology, customer choice and reliability for all customers.

  • State Ranking. Arizona ranks No. 3 nationally for solar capacity
  • Solar Capacity. Our company’s 1.4 gigawatts of solar capacity ranks No. 5 among all U.S. investor-owned energy companies
  • Solar Portfolio. Our portfolio includes 10 APS-owned large-scale plants, APS-owned rooftop solar systems and agreements to buy solar power from third-party providers, totaling 5.3 million solar panels (as of January 2019). We have helped more than 90,000 customers install private rooftop solar on their homes, and we have assisted more than 300 schools and 32 government agencies install solar projects at their facilities across Arizona. Learn more about our Renewable Energy Portfolio.

APS is pursuing numerous opportunities to advance Arizona’s solar leadership for the benefit of customers here and across the nation. Our engineers are developing and deploying innovative projects to understand solar’s potential for customers, including evaluating how solar interacts with energy storage and other advanced technologies.

Research from the award-winning APS Solar Partner program, Solar Innovation Study and APS Solar Communities program, among others, is being shared across the utility industry and with academic researchers, consumer advocacy groups and Arizona-based solar installers. The results are informing our company and the industry about how to bring the benefits of solar energy and advanced technology to customers reliably and affordably.

Energy Storage

APS will add 850 MW of battery storage and at least 100 MW of new solar generation by 2025, for a total of 950 MW of new clean energy technology. This represents a major down payment on Arizona’s continued progress toward an energy future that is clean, reliable and affordable.

Adding Storage to Existing Solar Plants. APS owns and operates large-scale solar plants throughout the state that will be upgraded with 200 MW of battery storage systems.

Building New Solar Storage Plants. APS plans to build an additional 500 MW of solar storage and stand-alone battery storage by 2025.

Delivering More Clean Energy When Needed. When solar production declines late in the afternoon and energy usage remains high, energy companies need a reliable, flexible source of power to serve their customers. Traditionally, that source has been exclusively natural gas, but energy storage provides a new direction. Through a recent RFP process, APS awarded 141 MW of solar-fueled battery storage and plans to issue additional RFPs for 159 additional MW to meet part of the energy demand when energy usage peaks. APS will own and operate these battery assets. This is in addition to over 200 MW of battery storage already awarded in Power Purchase Agreements (“PPA”).

Learn more about our battery storage projects.

Coal Reduction

We have permanently retired more than 1,000 megawatts of coal-fired electric generating capacity. These closures, in addition to other measures taken by APS, have resulted in a total reduction of carbon emissions of 28 percent since 2005, which is equivalent to removing over one 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 all plant closures, we work with employees and the local community as soon as possible to ease the transition. We strive to be open and transparent, and we provide as long a lead time as possible between decisions and effective dates. We participate in helping these communities with their long-term economic planning for a future beyond coal.

Carbon & Air Emissions

In 2018, the total APS carbon dioxide emissions were 13,137,903 tons. This represents a decrease of 28 percent over total carbon dioxide emissions since 2005.

In addition to carbon reductions, we are on the pathway to reduce nitrogen oxide (NOx) and sulfur dioxide (SO2) intensity by 93 percent and 89 percent, respectively.  Since 2005, we have had an intensity reduction of 77 percent for NOx and 86 percent for SO2. This resulted from our commitments to reduce emissions and institute operational efficiency enhancements.

APS reduces its environmental impact by closing older, less-efficient coal units and upgrading environmental controls on newer units. SCR technology currently is employed at six of our power plants. As noted above, installation of two new SCRs at the Four Corners Power Plant in 2018 resulted in an 88 percent NOx reduction at that facility

Learn more about our air emissions trends.

CDP Recognition. We believe it is important to disclose our carbon management strategies and GHG emissions to customers, investors and other stakeholders.  APS voluntarily reports annually to the CDP (formerly the Carbon Disclosure Project), a global nonprofit organization that collects and analyzes environmental data for investors to use in financial decisions. This organization’s network of investors represents more than $100 trillion in assets.  CDP reporting provides a benchmark to evaluate how well we manage our carbon emissions and climate change risk, and to identify opportunities for improvement.

We have been commended for our climate action in 2020, achieving a place on global environmental impact nonprofit CDP's prestigious ‘A List’ for climate change, based on our climate disclosure in 2019.   We are proud to be among 35 American companies to make the A-list; only 2 percent of companies disclosing to CDP made the list this year.  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.

Learn more about our CDP responses and documents.

Carbon Management

To measure our overall carbon reduction—not just decreasing emissions from generation but also throughout our company operations—we use a carbon-avoidance metric. This reflects actions taken company-wide, including retiring coal units, installing renewable generation and energy efficiency, increasing our building and operating efficiencies, and pursuing fleet electrification.

In 2018, we avoided 4.5 million metric tons of carbon. Since 2015, APS has avoided 18.1 million metric tons of carbon dioxide emissions that otherwise would have been emitted had we not taken actions to reduce the emissions. That is equivalent to removing almost four million automobiles from the road.

Sustainable Fleet

The APS transportation fleet continues its conversion to more fuel-efficient vehicles and electrification, by continually researching the market and updating the electrification strategy for our fleet. Through this ongoing conversion and by using our fleet more efficiently, we are working to reduce both carbon emissions and operating costs. The transition to hybrid technology in our fleet is driven by a favorable return on investment. Not only do we gain the benefits of hybrid technology, but our investment in hybrid vehicles does not exceed the cost of purchasing comparable petroleum-burning vehicles. We currently have a fleet of 27 sedans, of which 48% are plug-in hybrid electric vehicles. In addition, we are in the process of replacing all forklifts weighing 10,000 pounds or less with electric units.

New idle-mitigation technology is now standard on all troubleman 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 APS facilities. Our corporate headquarters in Phoenix has earned five ENERGY STAR labels for energy efficiency from the EPA. Over the past 12 years, we have improved energy efficiency at this facility by approximately 20 percent. Overall, APS facilities have received 10 ENERGY STAR labels. In 2018, due to efficiencies implemented, our electricity decreased 6 percent as compared to 2017 resulting in a reduction of 1,156 metric tons of carbon dioxide emissions.

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.

Our focus on green building principles was highlighted as part of a major construction project completed in 2018. Our final phase of renovation work completed within our DVN2 facility in Phoenix incorporated a wide range of sustainable design principles, materials and systems. Green features of the facility include utilization of LED lighting and electronic lighting controls, harvesting natural light through exterior windows and more than 100 roof skylights, higher efficiency mechanical systems, low-flow and low-flush water fixtures, thermal pane glass and low-VOC paint and flooring materials.

Going forward, 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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