Power Firms Jump on Data-Center Timeline From Biggest US Grid

Shares of power-plant owners climbed after the largest US electric grid accelerated plans to pair data centers with energy producers.

Constellation Energy Corp. and Vistra Corp. jumped about 6% Wednesday while NRG Energy Inc. gained 4.6% after grid operator PJM Interconnection LLC changed how data centers and suppliers contract together while moving up the date for the procurement of supply.

PJM has faced heavy criticism for being too slow to connect large data centers with power generation ahead of an expected surge in demand in the coming years. That’s raised concern over whether the grid can deliver reliable electricity during ...