The tangy smell of Buffalo wings filled Side Chicks Sport Bar, as a dozen electricians crammed their big frames into booths. It was Tuesday night in East Wenatchee, Wash., and “brotherhood night” for the electrical union. Out-of-towners and locals swapped notes on who was coming and going, when new jobs were starting and what drama had gone down with a foreman.

Sean Nickell, 32, and Chris Bennett, 35, sat in a booth below a television blaring a Seattle Mariners baseball game. For years, they had followed each other to job sites around the country without knowing it. “I have just met this man all of a monthish ago, and the parallels are horrifying,” Mr. Bennett deadpanned.

They were here to build data centers, the brawny concrete buildings with HVAC systems the size of tractor-trailers that power the new artificial intelligence systems that the tech industry believes are the key to its future — and perhaps the future of the entire economy.

Electricity is the lifeblood of technology. And perhaps more than any computer technology that has come before it, building A.I. needs vast amounts of computing and the electrical power to make that happen.