What the documents establish
In March, SoftBank said its SB Energy subsidiary had formed a public-private partnership to build an AI data centre at the US Department of Energy's site in Portsmouth, Ohio, describing it in its own words as the world's largest. As part of the same partnership SB Energy will build a gas-fired power plant nearby with a capacity of at least 9.2 gigawatts. The company also disclosed, in its reply to the June letter from Senators Elizabeth Warren and Richard Blumenthal and Representative Melanie Stansbury, that it contributed 50 million dollars to the Donald J. Trump Presidential Library Foundation in January.[1]
Those two dates are documented. On the physical side what is documented is a partnership announcement, a land lease and a capacity figure the company supplied itself. An energy project moves through announcement, contract, construction, delivery, energization and sustained use, and each of those transitions needs its own evidence. No commissioning date, interconnection application, permit filing or turbine order appears in the reporting.[1]
Why nameplate is the wrong denominator
Put the figures on one denominator. At least 9.2 gigawatts is the nameplate capacity of a generation facility; it is neither average load nor the draw of the data centre, and it has no direct relationship to delivered compute. For a gas plant on that scale the constraint ladder starts well before silicon: turbine lead time, gas supply, pipeline connection, air permitting and transmission. Not one rack in the data centre draws power until every step in that sequence is finished.[1]
The figure itself comes from a company statement rather than an audited filing. What I take from that is that 9.2 gigawatts may describe a long-term ceiling for the site rather than a facility to be built in one go. Another explanation is available: the company may genuinely be targeting that capacity in a single phase and the figure may rest on an interconnection application, but the existence of such an application is not stated in the reporting.[1]
The milestone to watch
The first checkable step from paper to hardware on this project is an air permit or an interconnection application that names the Portsmouth site and carries a capacity figure. If such a filing appears by June 30, 2027 and the figure in it stays materially below 9.2 gigawatts, the announced capacity should be read as a ceiling for the site rather than a build plan. If the filing arrives close to that figure, the project's bottleneck has moved to turbines and transmission.[1]