Power Drops on Eastern U.S. Grids as Milder Weather Cuts Demand

Texas spot wholesale electricity rose for the second time in three days as hotter weather swept across the state.

The high temperature in Houston today will be 94 degrees Fahrenheit (34 Celsius), 2 above normal, while Dallas will be 1 degree higher than the usual reading at 98 degrees, according to AccuWeather Inc. in State College, Pennsylvania. Prices for the highest demand hours of the day fell to a 15-week low last week as unusually mild weather reduced power consumption.

Demand on the main state grid operated by the Electric Reliability Council of Texas Inc. was 61,199 megawatts at 3:37 p.m. Central time, 1.1 percent higher than the day-ahead outlook for the hour.

Spot on-peak electricity at North hub, which includes deliveries to Dallas, gained $6.75, or 21 percent, to $38.18 a megawatt-hour at 3 p.m. from the July 19 full-day average, grid data compiled by Bloomberg show.

On-peak hours are Monday through Friday from 7 a.m. to 10 p.m. on the grid managed by

Ercot raised its forecast for peak demand for today to 61,239 megawatts during the hour ending at 5 p.m. from yesterday’s outlook of 6,312 megawatts.

On the East Coast, power prices plunged as a heat wave last week gave way to more seasonal weather in the Northeast and mid-Atlantic states.

New York

Spot on-peak electricity for New York City averaged $53.28 a megawatt-hour at 4 p.m. Eastern time, down $233.63, or 65 percent, from the full-day average on July 19, the day demand climbed to an all-time high in the city and across the state grid.

Boston prices plunged $196.62, or 60 percent, to $61.71 a megawatt-hour.

New England’s largest city traded at a premium to New York City for the first time in 11 days as demand on the six-state grid jumped above forecasts. Spot on-peak power for Boston is being valued at an average premium of $8.43 versus a discount of $16.19 on July 19.

On-peak electricity at PJM Interconnection LLC’s benchmark Western hub, which includes deliveries from Washington to Erie, Pennsylvania, fell $62.64, or 45 percent, to $50.72 a megawatt-hour.

Electricity use on the PJM network, stretching from New Jersey into North Carolina and Illinois, will peak at 135,167 megawatts today, 14 percent lower than the July 19 peak of 156,697 megawatts, according to PJM.

Nuclear Plant

PPL Corp.’s utility zone in eastern and central Pennsylvania is trading at premium to the benchmark after the company cut power at its Susquehanna 1 nuclear plant over the weekend. On-peak power averaged $61.40 a megawatt-hour at 4 p.m.

Susquehanna, about 50 miles (80 kilometers) northwest of Allentown, operated at 22 percent after performing planned repairs yesterday on four valves that control the amount of steam that go into the turbine, said Joe Scopelliti, a spokesman for the company. He said the unit will return to service after testing.

The reactor’s summer capacity is 1,261 megawatts, according to the Energy Information Administration.

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