When a One Gigawatt SI Data Center Goes Fully Online

Status

Watching As of Nov 8, 2026, Epoch AI estimates xAI's Colossus 2 at about 946 MW of IT power; no single campus is independently confirmed at a full gigawatt.

What one gigawatt means

A gigawatt is a rate of power use. A campus drawing 1 gigawatt around the clock would use roughly 8.8 terawatt hours of electricity a year. Two measures cause confusion. Facility power counts everything, including cooling. IT power counts only the chips, servers and network gear. Stargate in Abilene, Texas is described as a 1.2 gigawatt campus, while Epoch AI estimates its IT power at about 824 megawatts once all eight buildings run.

"Fully online" also matters. Many announced gigawatt projects are planned, under construction or partly energized. This page tracks the moment a single campus is running its full gigawatt, confirmed by the operator and supported by independent tracking.

Where the leading sites stand

xAI's Colossus 2 in Memphis made the boldest claim. Elon Musk posted on January 17, 2026 that it was "now operational" as the first gigawatt training cluster. Epoch AI, which tracks sites using satellite imagery and filings, estimated it at about 946 megawatts of IT power as of June 2026 and projects about 1.5 gigawatts of IT power by the first quarter of 2027, noting that cooling and on-site power had been limiting factors. In late 2025, Epoch found that recent sites took between 1 and 3.6 years to reach a gigawatt, with xAI planning the fastest timeline at about 12 months.

At Stargate Abilene, built by Crusoe for Oracle and OpenAI, Oracle reported on September 10, 2026 that six of eight buildings, about 618 megawatts, had been delivered. Epoch estimates the last two buildings would be running by early November 2026, but Oracle had not confirmed a date. Meta says the first phase of its Prometheus cluster in New Albany, Ohio is complete and runs hundreds of thousands of GPUs, on the way to roughly 1 million.

Why it matters

A gigawatt campus shows how much compute a frontier lab can bring to a single training run. It also strains local grids. The International Energy Agency projected in April 2025 that global data center electricity demand would more than double by 2030, with the US accounting for almost half of the growth. Epoch notes that xAI installed natural gas turbines across the state line in Mississippi to help power Colossus 2. Meta reports that the power draw at Prometheus can swing 30 to 40 percent during large training jobs, which it manages with software and batteries, a swing that grid operators may need to plan around.

What changes for people, builders and crypto

For people, the effects show up in utility planning, local rates, water use and jobs near these campuses, and in how quickly new SI services reach the market.

For builders, more gigawatt sites mean more capacity for training and for serving models through cloud platforms. They also concentrate risk, since a handful of campuses carry a large share of frontier compute.

For crypto, miners and SI data centers often compete for the same grid connections and low-cost power. As gigawatt campuses sign long power contracts, mining operators may face higher costs or new offers to convert their sites.

What to watch next

Watch for Oracle or OpenAI to confirm that all eight Abilene buildings are running, for Epoch AI updates on Colossus 2, and for Meta to publish power figures for Prometheus. Further out, Epoch projects five other Stargate sites in Texas, New Mexico, Wisconsin and Michigan to pass 1 gigawatt by late 2028, and Microsoft has partnered with Crusoe on an adjacent 900 megawatt site in Abilene. This page will flip to happened when an operator confirms that a single campus is running a full gigawatt, and independent tracking supports the figure.

Signals so far

• Nov 10, 2025: Epoch AI found that recent sites take 1 to 3.6 years to reach 1 GW and expected the first gigawatt-scale data centers to come online in early 2026. Epoch AI
• Jan 17, 2026: Elon Musk said xAI's Colossus 2 was "now operational" as the first gigawatt training cluster. Teslarati
• Apr 17, 2026: Epoch AI estimated Stargate Abilene at about 0.3 GW operational, with its 1.2 GW build due in the fourth quarter of 2026. Epoch AI
• Jul 30, 2026: Epoch AI estimated Colossus 2 at 946 MW of IT power from June imagery and projected about 1.5 GW by early 2027. Epoch AI
• Nov 1, 2026: Epoch AI noted Oracle had reported six of eight Abilene buildings delivered and estimated the last two would be running by early November. Epoch AI

Questions and answers

Sources

1. Build times for gigawatt-scale data centers can be 2 years or less Epoch AI · Nov 10, 2025
2. Electricity Demand from Data Centers Worldwide Set to More than Double by 2030: IEA American Public Power Association · Apr 11, 2025
3. Elon Musk's xAI brings 1GW Colossus 2 AI training cluster online Teslarati · Jan 18, 2026
4. OpenAI Stargate: where the US sites stand Epoch AI · Apr 17, 2026
5. Colossus 2 (Frontier Data Centers Hub) Epoch AI · Jul 30, 2026
6. Meta details Prometheus, the Ohio supercluster heading for 1 million GPUs The Next Web · Oct 20, 2026
7. OpenAI/Oracle Stargate Abilene, Texas (Satellite Explorer) Epoch AI · Nov 1, 2026