The largest US power grid failed for a third straight year to secure enough future supply commitments to ensure reliability for the future amid a historic boom in data center demand. PJM Interconnection, the largest US power grid (Regional Transmission Organization), which serves 67 million customers in 13 states and Washington, DC, said its auction to procure power for the year starting June 2028 fell 6.8 gigawatts short of what it will need to guarantee system reliability during demand spikes, in a statement released Tuesday. The shortfall is…