Power outages hit the US amid heat waves as electricity prices surge

The eastern US is grappling with a heat wave this week. The National Weather Service said tens of millions of people from Kansas to Maine face the risk of "extreme heat." US grid operators ordered power plants on Monday to maximize their output as wholesale electricity prices surged during a dangerous heat wave gripping the eastern half of the country.

PJM Interconnection, the largest grid operator in the US, serving one in five Americans, and Midwest-based MISO issued alerts to generators to be ready to operate at maximum capacity during the heat wave. Reuters reports.

The company also said it expected electricity demand to reach 160 GW on Monday, 158 GW on Tuesday and 155 GW on Wednesday. One gigawatt can power approximately 800 thousand households on a typical day, but far fewer on a hot summer day, when households and businesses switch on air conditioning.

When households and businesses switch on their air conditioners, the risk of power outages increases in extremely high temperatures if electricity generation is insufficient to meet rising consumption.

That happened in New York, the largest city in the United States, where temperatures climbed to 35°C. Several thousand Con Edison customers were left without power. Con Edison gradually restored service throughout Monday afternoon and evening.

"While Con Edison employees work to restore electricity to residents in areas of Staten Island affected by outages caused by extreme heat and humidity, the company is distributing dry ice to customers in the area,"the company said on its website.

The sharp rise in real-time prices signaled limited energy supplies in major metropolitan areas. Boston is one example: electricity prices there climbed in a single day from just under USD 50 per MWh to more than 400 dollars per MWh, according to ISO New England, the grid operator in the six-state region.

Meanwhile, grid operator New York ISO announced that wholesale electricity prices in the New York City zone exceeded 600 dollars per MWh on Monday evening. Temperatures are expected to start cooling on Wednesday.