T1 Energy’s G2_Austin solar cell fab in Rockdale, Texas, has its steel. FabArc Steel Supply of Oxford, Texas, has finished fabricating about 3,374 tons of structural steel for the plant, ENR reported Oct. 13: 749 columns, 4,459 beams, 222 roof trusses and roughly 6,800 square feet of grating. W.G. Yates & Sons Construction Co. is general contractor.
The plant targets the weak link in domestic solar manufacturing. U.S. module assembly has grown fast. Cell production hasn’t kept up, and cells are the harder product to make.
Project Scope
Phase one is a $510 million investment sized for up to 2.1 GW a year of high-efficiency TOPCon cells. A planned second phase would add 3.2 GW. The site covers more than 100 acres in Milam County. Cells will feed T1’s existing 5 GW G1_Dallas module plant in Wilmer, Texas, and the company has lined up Hemlock Semiconductor and Corning to supply polysilicon and wafers from Michigan.
SSOE Group has been on the project since site selection. It handled due diligence on environmental, utility, zoning and permitting issues, then master planning, mass grading and stormwater design. Yates came on for preconstruction and site prep before taking the building. PBI Inc. is erecting the steel, and International Design Services handled detailing.
The numbers have moved. In June 2025, T1 described an $850 million, 5 GW cell facility. When it announced the start of construction in December 2025, phase one carried an estimate of $400 million to $425 million, with production by the end of 2026. Now the phase-one figure is $510 million and operations are expected in the first quarter of 2027.
Why It Matters
Cell fabs sit much closer to semiconductor work than module lines do. The building is the easier part. Tool installation, process utilities and ramp-up are where U.S. solar factory schedules tend to slip, so getting steel done on time is a necessary step, not proof the plant will run on time.
The 20% rise in the phase-one number, from the top of the December estimate to today’s $510 million, is worth tracking but isn’t alarming for a first-of-its-kind build. A one-quarter slide in start-up is also modest. The real test is whether output reaches 2.1 GW once tools are running.
T1 says the project could support up to 1,800 jobs, and Milam County backed it with a long-term tax abatement package. If phase two follows, Rockdale becomes one of the larger cell production sites in the country, and Yates and SSOE would be the obvious team to carry it forward.
Project Team & Details
| Owner / Client | T1 Energy Inc. |
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| Consultants | SSOE Group (Engineering, Site Planning)
International Design Services Inc. (Steel Detailing) |
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| General Contractor | W.G. Yates & Sons Construction Co. |
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| Major Subcontractors | FabArc Steel Supply (Structural Steel Fabrication)
PBI Inc. (Steel Erection) |
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| Status | Under Construction |
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| Funding Source | Private |
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