On-peak power in Boston fell to the lowest level in almost a week as mild weather reduced electricity use.
New York City on-peak power, which traded at a premium to Boston, also slid.
ISO New England Inc. consumption was 16,199 megawatts at 11:10 a.m., below the day-ahead forecast of 16,680 megawatts, according to the grid’s website.
The high temperature Wednesday in Boston may reach 83 degrees Fahrenheit (28 Celsius), 9 above normal, according to AccuWeather Inc. in State College, Pennsylvania.
On-peak power in Boston fell $6.15, or 30 percent, to $14.59 at 11 a.m., heading toward the lowest full-day average since June 4, according to grid data compiled by Bloomberg. New York on-peak power dropped $2.23, or 11 percent, to $17.40.
Boston spot power reversed earlier declines and gained $1.67, or 9.9 percent, to average $18.47 a megawatt-hour at 11 a.m. from the same hour Tuesday, while New York spot power rose $1.48, or 8.7 percent, to average $18.42.
New York on-peak power traded $2.80 above Boston, compared with a discount of $1.11 on Tuesday and a three-month average discount of less than 1 cent for New York.
Spot power at PJM Interconnection LLC’s benchmark Western hub, which includes Washington, advanced $1.25, or 4.3 percent, to average $30.06 a megawatt-hour at 11 a.m. Power at the Eastern hub, which includes New Jersey, gained 35 cents to average $21.27.
PJM West on-peak power traded $3.16 above the Eastern hub, compared with a premium of $4.40 on Tuesday and a three-month average premium of $2.75 for PJM West.
Natural gas for July delivery rose 0.5 cent to $2.851 per million British thermal units at 11:55 a.m. on the New York Mercantile Exchange. About 30 percent of U.S. electricity is generated using gas.