Stargate Files for Phase 3 Expansion in Abilene

A new filing with the Texas Commission on Environmental Quality shows that Crusoe may be preparing another major scale-up at the Stargate campus in Abilene. The company has proposed two new data center buildings for Phase 3, each about 738,000 sq. ft and designed for 336 MW of total capacity. These facilities are significantly larger and more power-dense than the original Stargate buildings. If approved, they would move the campus beyond its initial plan and signal that OpenAI’s infrastructure strategy may involve not only launching new campuses but also expanding the ones already in place.

Expansion Scope

Each new Phase 3 data center building spans roughly 738,382 sq. ft and is rated for 336 MW power capacity. For comparison, the Phase 1 and 2 buildings (Buildings 1–8) were closer to 500,000 sq. ft and supported around 150 MW total, or roughly 37.5 MW per data hall. Those earlier phases also used Stargate’s distinctive angled, multi-segment layout, while the filings show that Buildings 9 and 10 shift to a more conventional rectangular design.

The new buildings are larger and significantly more power-dense, with each carrying about 30% more IT load than an original Stargate building. They also introduce dedicated Central Utility Plant (CUP) buildings, infrastructure that the earlier phases did not include.

The new buildings add about 672 MW, bringing Phase 3 of Stargate to roughly 1.9 GW from the current 1.2 GW plan.

Source: Texas Commission on Environmental Quality (TCEQ)

On-Site Power

To fuel this growth, the upcoming phase introduces a significant amount of on-site generation to support high-density compute:

• 29 GE LM2500 and 12 Aero DT35 natural-gas turbines (34.1 MW each), operating up to 8,760 hours per year
• 12 CAT 3516 diesel backup generators (3 MW each).
• 6 CAT 3516 black-start generators (3 MW each).

These new turbines will serve as dedicated on-campus generators for power to serve the increased load. To put it in context, the campus currently has ten turbines from earlier phases (five GE LM2500s and five Titan 350 units). With 41 new units proposed, Crusoe would be moving from 10 to a total of 51 natural gas turbines on-site, effectively turning the Abilene campus into its own large-scale power plant.

Interestingly, although Phases 1 and 2 (Buildings 1-8) technically include 62 diesel generators on paper, none of those units have been installed on the campus to date. The same pattern could apply here: while 18 new generators (12 backup + 6 black-start) are listed in the latest filing, they may not arrive right away. The document does however make one thing clear, once the campus is fully built out, Stargate is expected to host 80 generators in total, indicating these units will likely be added gradually as new buildings come online and load increases. Importantly, Crusoe mentions in the filing these generators are intended only for emergency operating scenarios when a turbine is offline, a condition it expects to occur no more than 150 hours per year.

Outlook

The broader picture from this filing is that OpenAI’s strategy extends beyond opening new campuses. The company also appears to be expanding its flagship sites as they mature. Stargate’s next phase shows that existing campuses may continue to grow well beyond their original footprints as compute demand accelerates.

For a deeper look at the U.S. data center landscape, explore Aterio’s latest U.S. Data Center Report for state-by-state insights, provider comparisons, and project pipeline analysis, or schedule a call to learn more about how Aterio’s data can support your work.