Overview
PJM, which manages the largest U.S. wholesale electricity grid serving roughly 67 million people across the Mid-Atlantic, parts of the South and Washington, D.C., has flagged elevated operational risks as a heatwave pushes demand higher ahead of July 4. Early on Wednesday, spot wholesale prices in parts of PJM's footprint climbed to nearly $300 per megawatt hour, compared with typical off-peak or milder-period spot prices of about $25 to $40 per MWh.
Voltage and reliability alerts
The grid operator issued a low-voltage alert indicating an increased risk of rotating outages as voltage levels on some transmission lines weaken under stress. PJM has also contacted generators to accelerate returns from maintenance so plants can be available to respond to rising load.
What operators are forecasting
PJM's forecast highlights a particularly acute test scheduled for roughly 6 p.m. EDT on Thursday, when demand is projected at 166.3 gigawatts. That would exceed the existing all-time PJM peak of 165.6 GW recorded 20 years ago, according to PJM's latest forecast.
To cover sudden deficits, PJM reports roughly 18 GW of reserve resources that could be brought online within 30 minutes. PJM notes that level is about six times the minimum reliability requirement.
Price spikes and congestion
Operators warned that spot prices are likely to jump sharply in response to constrained transmission, with local prices potentially topping $1,000 per MWh on Wednesday evening as PJM manages congestion around Virginia's data center cluster and dispatches higher-cost generation, largely gas and coal-fired units, to meet peak consumption. Earlier in the day, parts of the system were already seeing prices approach $300 per MWh.
Expert assessment
Grid expert Georg Rute, CEO of Gridraven, said, "extreme heat, low wind and surging demand are coinciding at a time when transmission lines have the least margin for safety." He added that this combination is pushing up the cost of moving power amid heavy congestion, which in turn drives the observed price spikes.
Regional conditions
Temperatures are forecast to hover near 100 degrees Fahrenheit (38 degrees Celsius) from Boston south to Washington, D.C., including Northern Virginia where a dense concentration of data centers is located. That level of heat is expected to boost air-conditioning load and add stress to PJM and neighboring grids.
The Midcontinent Independent System Operator (MISO), which operates across 15 U.S. states in the Midwest and the South, also faces the possibility of setting a new demand record as early as Wednesday evening; MISO's current record sits at 127.1 GW and forecasts indicate it could be challenged.
This report focuses on operational conditions and forecasted demand, prices and reserves as provided by the grid operators and the expert cited. It does not add or infer information beyond those disclosures.