Amazon is backing a Pecos County, Texas campus served by 35 natural gas turbines capable of 7.65 gigawatts, permitted to emit 33 million tons of carbon dioxide a year, which would make it the largest single emissions source in the US power fleet, according to SiliconANGLE's coverage of reporting by Hiroko Tabuchi at the New York Times. Amazon spokeswoman Margaret Callahan said the company's commitment has not changed, and that "the world looks different now than when we co-founded the climate pledge." Roughly 90 percent of new Texas grid interconnection requests now come from data centers, together asking for about 474 gigawatts, near five times the state's record peak demand. Off-grid gas has been the release valve on that queue for a year.
Going off-grid means the campus builds its own generation and its own heat rejection, and only one of those two decisions is a public filing. West Texas hands an operator one genuine gift: a dry climate means a low coincident wet bulb, so an evaporative tower gets a colder approach than it would on the Gulf Coast and does more work per gallon. The gallon is the problem. Makeup water in the Permian Basin comes out of an aquifer that oil and gas, agriculture, and municipalities are already drawing against, in a county where the regional data center water draw is measured in billions of gallons. An air-cooled or dry-cooled design avoids that argument entirely and pays for it in chiller electricity, which means more turbines.
Combustion turbine output falls as inlet air temperature rises, which is why large gas plants in hot climates install evaporative inlet coolers or inlet chillers to hold capacity through an August afternoon. Those systems consume water. Lube oil and generator coolers add more. If any part of the plant runs combined cycle, a steam condenser and its own cooling tower join the balance, and the water math changes by an order of magnitude depending on which configuration the filings actually describe. The published figures cover emissions and capacity. The water balance for the generation half of this campus is not something we have seen, and it is the larger of the two draws in most plant designs of this size.
Zoom out and the pattern is national rather than Texan. At least 82 data-center-linked gas generators are in development or proposal across the United States, with permits in states including Texas and Ohio cleared in as little as 18 days, according to Futurism's tally published August 8. Eighteen days is not enough time for an air district to model a plume, let alone for anyone to ask what the tower blowdown does to the receiving stream. The climate pledges are already broken. The open question is whether the cooling architecture on these off-grid campuses gets specified for the water table underneath them or for the capital budget above them, and right now nobody outside the developer knows which.