As electricity demand surges, the United States is facing a trillion-dollar race to rebuild its aging power grid. But even as utilities and policymakers pour funding into modernization efforts, a critical choke point has emerged: a years-long shortage of transformers that is slowing the upgrade process.

America’s power grid infrastructure is between 40 and 100 years old, depending on the location. Parts of the grid date back to the late 1800s. Recent estimates suggest the United States will need $1.4 trillion by 2030 and more than $3 trillion by 2035 to modernize and expand its electrical infrastructure.