From Arizona AI · Nov 3, 2026 · Data centers

Cochise County: 747-Acre AI Data Center Campus, Estimated 6 GW Power Demand Proposed

November 3, 2026 | Arizona AI

Cochise County has received an application for a proposed nine-building AI computing campus near Cochise, Arizona. The developer estimates electricity demand could reach 6 gigawatts at full build-out. That is a projected maximum, not power the project has secured or approval to develop the site.

The application, SU26-22, was submitted October 30, 2026, by Tombstone Resources L.L.C., a proposed AI and supercomputing campus developer. Cochise County announced its receipt November 2. The site covers approximately 747 acres of rural-zoned land near the Apache Generating Station, east of U.S. Highway 191.

According to the county's official project summary, the proposal includes up to nine computing buildings in four phases, with battery energy storage, electrical and cooling equipment, and supporting facilities. The county says the applicant's plans and operating estimates have not yet been independently verified or endorsed and remain subject to review.

What does 6 GW mean?

The developer's special-use application estimates that the full campus could draw approximately 6 gigawatts (6,000 megawatts) of electricity. Sulphur Springs Valley Electric Cooperative (SSVEC), the member-owned electricity distributor that would serve the proposed development, describes a proposed initial phase of 1.5 GW to be developed in three stages. The developer proposes additional phases that could eventually reach the 6 GW figure.

This is a demand estimate, not installed generating capacity, a guaranteed power supply, or permission to begin construction. SSVEC states that engineering studies and system improvements would be required before each stage could receive electricity.

For scale, Arizona Electric Power Cooperative (AEPCO), the power-generation and transmission cooperative that supplies SSVEC, lists more than 1,170 MW of generating and storage capacity at its nearby Apache site. The proposed 6,000 MW demand is roughly five times that figure. This comparison does not establish that the project would rely solely on Apache Station; additional resources could be developed, purchased, or transmitted from elsewhere. It does illustrate the scale of power arrangements still to be made.

To put 6 GW into context, 6 Gigawatts would be able to cover between 1.15 million and 3.7 million Arizona households, depending directly on the generation source and its capacity factor.
The largest power plant in the United States is Palo Verde (the nuclear plant west of Phoenix) which has a total nameplate capacity of roughly 4.0 GW (4,000 MW). This single proposed data center campus in Cochise County would demand 1.5 times the maximum output of Palo Verde running at full tilt.

The applicant's filing also describes a proposed 24-gigawatt-hour battery energy storage system, along with limited natural-gas standby generators for critical equipment. Neither batteries nor those standby generators constitute a source of electricity sufficient to operate a 6 GW campus continuously.

Electricity agreements and infrastructure remain unfinished

SSVEC says it would distribute electricity to the site, while AEPCO would handle the necessary transmission and substation infrastructure. The developer and cooperatives would need to sign an Energy Services Agreement covering service and associated costs. No final agreement has been announced, and any agreement is subject to approval by the Arizona Corporation Commission (ACC), the state utility regulator.

The application estimates approximately $3.6 billion in transmission and substation upgrades funded by the developer. This is the applicant's projection, not a completed or approved infrastructure investment.

In August 2026, the ACC approved a general process for reviewing large-customer power agreements. That action did not approve this proposed campus's individual electricity service agreement.

SSVEC says it is negotiating provisions intended to prevent project-related infrastructure costs and financial risks from falling on existing cooperative members, including protections if the project uses less electricity than expected or closes early. Those terms have not been finalized. The cooperative also says its anticipated future rate-case filing is driven by existing cost pressures, independently of this proposed development.

Land ownership, buildings and requested exceptions

The developer's application identifies two adjoining properties: approximately 400 acres owned by AEPCO and 348 acres owned by Southline Transmission LLC. Tombstone Resources says it is under contract or agreement concerning those properties. The application does not establish that the developer already owns the land.

The submitted design calls for up to nine single-story computing buildings of approximately 493,000 square feet each. The applicant is requesting several departures from normal rural development standards, including permission for buildings and outdoor equipment up to 40 feet tall, greater site coverage, and construction around the clock during project phases.

These are requests for county consideration, not granted exceptions. Building placement and other site details are preliminary.

Water, wildlife and emergency services

The developer proposes dry cooling, using recirculating liquid and air-cooled equipment rather than ordinary cooling towers. It estimates approximately 7 to 10 acre-feet of water per year, or about 2.3 million to 3.3 million gallons, during full operation, mainly for staff-related uses. It proposes no new groundwater production well for cooling and identifies treated water from the neighboring generating station or trucked water as possible supplies.

These figures and methods come from the developer's application; neither the water demand nor the proposed supplies should be treated as independently verified. Construction and initial cooling-system filling would have additional water needs.

The nearby Willcox Playa is used by migratory sandhill cranes. The applicant describes proposed measures concerning lighting, drainage, building design, and wildlife movement. Relevant environmental and site reviews remain pending.

The application also states that the property is outside an existing fire district. The developer proposes private on-site fire-protection infrastructure and says it will seek an emergency-response arrangement with a neighboring district. The county must evaluate applicable safety and emergency-access requirements, including those associated with battery storage.

Jobs and financial benefits are projections

Tombstone Resources estimates that construction could employ about 5,500 workers at peak, with approximately 1,000 permanent operations, security and maintenance positions, including contractors, at full build-out.

Its filing also projects $34 million to $103 million in additional annual property-tax revenue and potential reductions of 10% to 40% in electricity bills for SSVEC customers. The proposal describes further potential community funding and cooperative-member benefits.

These are the applicant's estimates and proposed financial outcomes, not verified job commitments, adopted tax forecasts, or guaranteed electricity-rate reductions. The utility agreement, financing arrangements, assessed property values, and other decisions would influence any eventual results.

Public meetings and next steps

Applicant-hosted community meeting

Wednesday, November 4, 2026, at 6 p.m. Arizona time
Cochise Elementary School, 5025 N. Bowie Avenue, Cochise, AZ 85606

This meeting is organized by Tombstone Resources for questions and discussion. It is separate from the county's formal public hearing.

Cochise County Planning and Zoning Commission hearing

Wednesday, December 9, 2026, at 4 p.m. Arizona time
Board of Supervisors Meeting Room, 1415 W. Melody Lane, Building G, Bisbee, AZ

The Commission may approve the special-use request, approve it with conditions, or deny it. Its decision is final unless appealed to the county Board of Supervisors under the zoning rules. Even a special-use approval would not replace subsequent building, fire, and other required permits.

Residents can review application materials and submit public comments through the county's data center project page. The application docket is SU26-22 191 Data Center and BESS.

As of November 3, the proposal remains under review. Its eventual size, electricity supply, schedule, financing, environmental conditions, and public benefits are not settled.

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### Primary sources

1. Cochise County: data center project page and application status, updated November 2, 2026.
2. Tombstone Resources L.L.C.: original special-use application and appendices, hosted by Cochise County (PDF), dated October 30, 2026. Project specifications and developer estimates are attributed to this filing, not to county findings.
3. Cochise County: November 2 public announcement, for receipt date and public meeting details.
4. Sulphur Springs Valley Electric Cooperative: project FAQ, for utility roles, proposed phase-one load, and status of electricity agreements.
5. Arizona Electric Power Cooperative: Apache Generating Station capacity, for the scale comparison.
6. Arizona Corporation Commission: August 13 large-load agreement framework announcement, for regulatory context.

Reporting status: November 3, 2026. Figures from the applicant's filing are preliminary and have not been independently validated by Cochise County.