美国芝加哥出现负电价，发生了什么？

Group 1 - The severe winter storm has led to a surge in electricity demand, but the transmission capacity of high-voltage power lines in the Chicago area has reached saturation, causing electricity prices to drop into negative territory, with a recorded price of -227.93 USD per megawatt-hour [1][7] - The storm has resulted in at least 25 fatalities across the United States, with New York reporting 8 deaths outdoors and other incidents occurring in Texas, Arkansas, Massachusetts, and Kansas [3][9] - Nearly 700,000 users remain without power as of January 26, with 22 states declaring a state of emergency and over 13,000 flights canceled due to the storm [4][10] Group 2 - The storm is attributed to the expansion of the polar vortex, which has been linked to climate change, leading to more frequent extreme weather events [5][11] - Scientific rebuttals have emerged against claims that the storm contradicts global warming, emphasizing that cold days and winter events will not disappear entirely, but their frequency may decrease [5][11]