Oct. 7 (Bloomberg) -- Spot wholesale electricity declined on grids stretching from Maine to Virginia as rain moved into the region, cutting demand.
New York prices reversed earlier gains as demand slipped below forecasts. Spot power had surged to more than $200 a megawatt-hour across the state grid after an unplanned shutdown of a high-voltage line reduced imports. Demand also slumped in New England and on the 13-state PJM Interconnection LLC network.
Spot on-peak electricity for New York City slid $11.82, or 19 percent, to average $49.26 a megawatt-hour as of 4 p.m. from the Oct. 4 full-day average, grid data compiled by Bloomberg showed. Boston dropped $21.91, or 37 percent, to $37.12.
New York City prices jumped from the low $30s after the 345-kilovolt Homer City-Stolle transmission line, from Pennsylvania into southwestern New York, experienced a forced outage over the weekend, according to the New York Independent System Operator Inc.’s website.
The transmission line delivers power from the 1,884- megawatt Homer City Generating Station. The coal-fired power plant, about 45 miles (72 kilometers) northeast of Pittsburgh, is operated and maintained by NRG Energy Corp., according to the plant’s website.
Power demand in Manhattan and its four neighboring boroughs was 7,805 megawatts at 3:15 p.m., 0.4 percent below the day- ahead forecast for the hour, data from the NYISO show. Demand was coming in about 1 percent above forecasts earlier.
The high temperature in Midtown Manhattan today may be 73 degrees Fahrenheit (23 Celsius), 6 above normal, according to AccuWeather Inc. in State College, Pennsylvania. Temperatures in Washington dropped to 63 at 3:29 p.m. after reaching a high of 78 degrees four hours earlier.
Spot on-peak prices for PJM’s benchmark Western hub, which includes deliveries to Washington, fell $6.29, or 13 percent, to $42.52 a megawatt-hour as of 3 p.m. from the Oct. 4 average.
Power consumption on the PJM grid was 92,025 megawatts at 3:25 p.m., 0.3 percent above the day-ahead forecast. Demand had exceeded the previous day’s outlook by more than 3 percent just before noon.
Midwest prices were bolstered by a drop in nuclear and wind generation that contributed to supply bottlenecks on the grid, data from the Midwest Independent Transmission System Operator Inc.’s website show. On-peak power at the Illinois hub gained $10.64, or 28 percent, to $48.94 as of 2 p.m. local time from the Oct. 4 average.
Exelon Corp. cut output at its Clinton 1 reactor in Illinois to 3 percent of capacity from 96 percent yesterday, Nuclear Regulatory Commission filings show.
Wind generation dropped today to a low of 1,392 megawatts at 11 a.m. local time, 33 percent below the projection for the time. Three hours later, output from the grid’s turbines jumped to 2,016 megawatts, 8.3 percent above the day-ahead outlook, helping to ease prices.
Prices also slumped on the Electric Reliability Council of Texas Inc. grid as demand fell 8 percent below forecasts. The on-peak power at the North hub, which includes Dallas, dropped $7.45, or 22 percent, to $26.93 a megawatt-hour as of 3 p.m.
--Editors: Bill Banker, Margot Habiby