PJM Interconnection - the electricity grid operator - says a new winter peak of more than 138,000 megawatts was reached Tuesday morning.
High energy usage is anticipated Wednesday morning, as well, putting stress on generating plants.
Ways you can conserve energy include turning off the lights, unplugging electronics and postponing the use of major appliances like stoves, dishwashers and laundry machines.
Officials say the most critical time to conserve is between 6 a.m. and 9 a.m. Wednesday morning.
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