The forecasts are eye-popping: utilities saying they’ll need two or three times more electricity within a few years to power massive new data centers that are feeding a fast-growing AI economy.

But the challenges — some say the impossibility — of building new power plants to meet that demand so quickly has set off alarm bells for lawmakers, policymakers and regulators who wonder if those utility forecasts can be trusted.

One burning question is whether the forecasts are based on data center projects that may never get built — eliciting concern that regular ratepayers could be stuck with the bill to build unnecessary power plants and grid infrastructure at a cost of billions of dollars.

“There’s speculation in there,” said Joe Bowring, who heads Monitoring Analytics, the independent market watchdog in the mid-Atlantic grid territory. “Nobody really knows. Nobody has been looking carefully enough at the forecast to know what’s speculative, what’s double-counting, what’s real, what’s not.”

There is no standard practice across grids or for utilities to vet such massive projects, and figuring out a solution has become a hot topic, utilities and grid operators say.

The effort to improve forecasts got a high-profile boost in September, when a Federal Energy Regulatory Commission member asked grid operators for information on how they determine that a project is not only viable, but will use the electricity it says it needs.

“Better data, better decision-making, better and faster decisions mean we can get all these projects, all this infrastructure built,” the commissioner, David Rosner, said in an interview.