The numbers in the two ledgers
South of Memphis, on the Mississippi side, 69 gas turbines are running today without permits at the Colossus data centres that feed xAI's AI compute. The permit issued for the permanent solution covers a natural gas plant of 41 turbines, each between 16.48 and 50 megawatts, reaching 1.2 gigawatts in total. Those two figures are different rungs of the same system: one is hardware feeding today's load without a permit, the other is permitted capacity that has not been built.[1]
The permit for 41 turbines carries a range inside it. Built entirely at the lower bound it comes to roughly 675 megawatts; entirely at the upper bound, a little over 2 gigawatts. The announced 1.2 gigawatts sits inside that range, which shows the turbine mix is not uniform. A permit defines nameplate capacity, not electricity produced. How many megawatts actually come into service can be measured only after the construction and interconnection rungs.[1]
What the trailer argument rests on
SpaceX argues that no permit is needed for the running turbines because they sit on shipping trailers. Federal regulations do not match that reading: the size of the turbines and the way they are used determine whether the installation counts as a stationary source. What the dispute turns on is the duration and the load at a single point, rather than whether the hardware sits on wheels.[1]
The most direct explanation of the one-year overlap is that the unpermitted fleet carries the load until the permitted plant comes online. The competing account is ordinary construction sequencing: removal may sit late in the schedule because it depends on commissioning the new plant, in which case the overlap is a consequence of the build order rather than a designed bridge. What separates the two is whether the 69 turbines leave the site in stages or all at once.[1]
What is measurable and what is not
The existing turbines have the potential to emit more than 2,000 tons of smog-forming nitrogen oxides a year. That is a ceiling used in permitting arithmetic, not a measured annual figure. Actual emissions fall below it depending on operating hours, load profile and fuel consumption. Supporting SpaceX in litigation brought by the NAACP and the Southern Environmental Law Center, the Department of Justice framed the matter in terms of national, economic and energy security; that is a legal position, not an engineering quantity.[1]
The rung to watch is clear. If part of the 69 turbines leaves the site by 31 December 2026, removal has been tied to commissioning the permitted plant and the construction-sequencing account strengthens. If the count is still 69 by then, the fleet was planned to carry the load until July 2027. The difference can be counted on site, so it settles without any interpretation.[1]