US DOE warns of blackout risk as heatwave strains PJM grid

The US Department of Energy has warned of elevated blackout risk in the PJM Interconnection, the largest US grid serving 67 million people from Washington DC to Chicago, as a heatwave tests capacity. The warning signals potential strain on electricity supply across the Midwest and mid-Atlantic, with uncertainty over whether demand will outpace generation. This matters as prolonged outages could disrupt economic activity and highlight grid resilience gaps.