People rest in the shade at the Great American State Fair, during an extreme heat wave (AP photo)
A massive heat wave across eastern US pushed electricity demand close to record levels on Friday, prompting the country’s largest power grid operator to activate emergency measures to reduce consumption.PJM Interconnection, nation’s largest supplier which provides electricity to about 67 million people across parts of the East Coast, Midwest and Washington, DC, ordered customers enrolled in emergency demand-response programmes to cut power use during peak evening hours. The move came as the grid grappled with generator outages, overloaded transmission lines and soaring air-conditioning demand, reported Reuters.The operator said the emergency action was aimed at increasing reserve capacity and preventing blackouts as electricity demand surged. It also alerted neighbouring grid operators, including those in New York and the Midwest, that power exports from the PJM network could be curtailed if necessary.The strain comes as around 160 million Americans remain under major or extreme heat warnings during the July 4 holiday weekend, with temperatures nearing or breaking records across much of the eastern US, according to the National Weather Service. On Thursday, PJM’s electricity demand reached about 163 gigawatts, just below its all-time record of 165.6 gigawatts set two decades ago. The operator avoided outages by relying on demand-response programmes, which compensate participating residential and industrial customers for reducing electricity use during emergencies, as well as costly standby “peaker” power plants.A hot weather alert remains in effect across the PJM region through Saturday and has been extended through Sunday for parts of the Mid-Atlantic and Dominion transmission zones, home to one of the world’s largest concentrations of data centres.The surge in demand also sent wholesale electricity prices soaring. Spot power prices in parts of the Mid-Atlantic and Dominion transmission zones climbed above USD 2,500 per megawatt-hour this week, compared with roughly USD 40 per megawatt-hour under normal operating conditions.The heat wave has disrupted July 4 celebrations across the country. In Washington, DC, events on the National Mall were temporarily suspended after multiple people suffered heat-related illnesses, while the city’s Independence Day parade scheduled for Saturday was cancelled because of the extreme weather.New York City also expanded cooling centres and extended public swimming pool hours as the heat index climbed above 100 degrees Fahrenheit. Utility provider Con Edison said it restored power to about 60,000 customers following heat-related outages, although more than 22,000 users in the city and nearby suburbs remained without electricity on Friday afternoon.
