Spot wholesale electricity rose on the largest U.S. grid as hotter-than-normal weather in the mid-Atlantic states spurred air-conditioning demand.
PJM Interconnection LLC said power consumption from New Jersey to Virginia on the eastern part of the grid was 51,855 megawatts at 2:30 p.m., 4.3 percent higher than the day-ahead forecast for the hour. The western region was 2.2 percent lower than forecast.
This difference in demand in the regions was driven by unusually cool air sweeping parts of the Midwest, contributing to bottlenecks on transmission lines to get power into the hotter regions, according to PJM’s website. The high in Chicago today may be 71 degrees Fahrenheit (22 Celsius), 13 below normal, according to AccuWeather Inc. Washington will be 6 higher than average at 94 degrees.
“Demand strength across the East Coast, combined with weakness in western PJM, is causing transmission bottlenecks,” said Diana Chiyangwa, a Boston-based power analyst for Genscape Inc. The bottlenecks are affecting the flow of power from Ohio and West Virginia down to Virginia, she said.
Spot power for PJM’s Eastern hub, which includes New Jersey, eastern Pennsylvania, Maryland and Virginia, gained $15.20, or 28 percent, to $70.29 a megawatt-hour in the hour ended at 2 p.m. from the same time yesterday. PJM’s benchmark Western hub rose $12.50, or 24 percent, to $64.28.
The premium for on-peak power for the Eastern hub versus the Western hub widened to $2.83 from yesterday’s average of $2.51. The three-month average premium is $6.43.
PJM manages the 13-state grid from the mid-Atlantic states to the Midwest, serving more than 61 million people.