One hundred years ago, a small group of farmers and local leaders in the Arizona desert came together with a shared vision: to bring electricity to their farms and rural communities in Pinal County. This year, ED3 proudly celebrates its 100th anniversary, marking a century of reliable service, system growth, and community partnership.

In the 1920s, rural electrification in the United States was largely stalled. While urban areas and industries were widely electrified, most farms and rural areas were still without power. Private investor-owned utility companies considered it unprofitable to extend costly power lines to sparsely populated areas. In 1922, an Electrical District Act was passed by the legislature to authorize the creation of electrical districts. The goal was to bring power and water to rural, agricultural focused communities, a mission that began decades before the federal government’s nationwide rural electrification program. In 1926, that vision became reality locally in Maricopa with the creation of Electrical District No. 3 (ED3).

For a century, ED3 has embodied the enduring principles of public power — local control, accountability, affordability, and service to community — while continually adapting the business to meet the evolving needs of its customers and the challenges of a changing energy landscape.

Farming in the desert and federal hydropower

Farmers in the fertile lands near Maricopa and Casa Grande recognized that reliable access to electricity was essential to modern agriculture and community life. In its earliest days, ED3’s system was simple but effective: a few miles of poles and wires delivering power to irrigation pumps, farms, and small businesses. Electricity transformed the area’s potential, turning arid desert fields into thriving farmland and enabling families to build homes and small rural businesses.

At its peak agricultural roots, ED3 served over 86,000 acres of farmland including the area today known as the City of Maricopa. Initially, power was purchased from an investor-owned utility and later affordable federal hydropower resources were added upon the completion of federal dam projects, like Hoover Dam when it first delivered power to Arizona in the late 1930s. Today, ED3’s power supply portfolio still includes federal hydropower resources from the Arizona Power Authority (Hoover Dam), the Parker-Davis Project, and the Colorado River Storage Project (CRSP).

A legacy of local ownership and adaptability

From the beginning, ED3 has met the needs of the local community. Unlike private utilities, public power districts have no shareholders — every dollar earned is reinvested locally to

maintain and improve service, keep rates affordable, and fund community initiatives. This local ownership model has given ED3 both stability and flexibility through changing times. A few critical events over the past 100 years include:

1926 – ED3 was formed Jan. 5.

1960 – Entered into an Operating Agreement with APS and purchased some additional facilities.

1989 – ED1 and ED3 consolidated into ED3 enlarging the service territory.

2001 – ED3 ended the APS Operating Agreement and subsequently purchased Sexton Substation and facilities expanding ED3’s service territory.

2006 to 2010 – ED3 and APS reach a tentative agreement to purchase an area of the district including the Hidden Valley (previously part of APS) area which allowed ED3 to add over 3,000 customers. The ACC approved the sale from APS to ED3 in 2010.

2011 – ED3 received an A credit rating from Standards and Poor’s (S&P) and refinanced $120 million in bonds that helped fund electrical infrastructure in support of the creation and expansion of the City of Maricopa.

2014 – ED3 was a founding member of the Southwest Public Power Agency, a joint action agency formed to work with other like-minded entities to procure long-term power resources. The Southeast Valley 500 kV transmission line was completed expanding transmission access to ED3.

2020 to 2030 – Greatly expanded power supply resources by expanding the Mesquite Generation Station capacity contract to 210 MW and added 100 MW of solar energy to the power supply portfolio from Box Canyon Solar and Apache Solar II. Became a member of Arizona Electrical Power Cooperative (AEPCO) and announced participating in an additional Pinal County solar and battery project tentatively scheduled for completion by December 2027. From 2020 to 2030, ED3 is expected to invest over $175 million in distribution and transmission projects.

Building and investing for growth and reliability

What began as a rural distribution system for a handful of farms has become a modern grid serving one of the fastest growing regions in the United States that includes residential subdivisions, schools, and commercial centers.

ED3’s service area encompasses over 350 square miles, serves approximately 36,000 meters, and had a peak system demand of 280 megawatts (MW) as of August 7th, 2025. The district has focused on capital planning and system modernization, incorporating

advanced metering and grid monitoring technologies that allow faster response times and improved efficiency. In 2025, ED3 announced the 2-year transition to a new enterprise software platform, NISC, to access advanced technologies including an improved customer app. The technology project is the first major enterprise system overhaul since the 2010 enterprise software implementation.

The district’s 5-year 100+ million capital improvement plan prioritizes investments in transmission and distribution substations including planned expansions to the WAPA Test Track substation, Sonny Dunn substation, Kelly Substation, Anderson Substation, Sexton Substation, Wingfield Substation, and Peters and Nall Substation. ED3 is currently working with Western Area Power Administration (WAPA) on a second interconnection to the bulk electric system, which will improve reliability and capacity into ED3’s system. The second 500 kV transmission line to Pinal West and a new transformer at SRP Duke Substation will also enhance transmission to ED3 with a slated completion date in 2028.

As Arizona continues to grow, so does the demand for energy solutions. ED3 has been proactive in advancing renewable energy, energy efficiency, and sustainability initiatives that support both environmental responsibility and economic growth. In recent years, ED3 earned national recognition from the American Public Power Association as a Smart Energy Provider (SEP) and as a Tree Line USA utility from the Arbor Day Foundation.

The district has committed to 138 megawatts of solar generation projects and 85 megawatts of four-hour battery energy storage systems, expanding the use of clean energy while maintaining reliability during peak demand periods. These efforts help diversify ED3’s energy portfolio, reduce carbon emissions, and position the power supply portfolio with long-term energy resources. ED3 continues to evaluate other infrastructure and power supply projects in the region to help meet future needs as urbanization in Pinal County continues.

Honoring the people behind the power

At the heart of ED3’s success are the people who make it all possible. From the linemen who brave the desert heat to set poles, to skilled engineers, technicians, and customer service representatives, ED3’s employees have always exemplified dedication and pride in their work.

“Reaching our 100th anniversary is an incredible achievement made possible by the dedication of our employees across the organization in various disciplines.,” said Brian Yerges, General Manager of Electrical District No. 3. “For a century, ED3 has remained true to its public power roots — providing reliable, affordable energy while investing in the

communities we serve. As we look ahead, we’re committed to delivering on that for future generations.”

From its origins as a small desert utility to its position today as a modern utility serving approximately 36,000 meters, ED3 stands as a proud example of what public power can achieve. For 100 years, ED3 has powered homes, farms, and businesses — lighting Central Arizona’s past and leading it confidently into the future.

SPONSORED CONTENT