极端寒潮冲击美国电力系统，芝加哥电价为何跌入负值？

Core Insights - The severe winter storm has put significant pressure on the U.S. power system, leading to increased heating demand and soaring electricity prices in many areas, while some regions, particularly in the Midwest, have experienced rare negative electricity prices [1][4]. Group 1: Impact of Winter Storm - The winter storm has affected approximately two-thirds of the eastern U.S., causing over 580,000 households and businesses to lose power due to downed trees and ice on power lines [1]. - The storm's extreme cold is expected to persist throughout the week, raising safety risks associated with power outages [1]. Group 2: Electricity Price Surge - The benchmark hub price in the PJM region surged to $638.73 per megawatt-hour during peak hours, marking a 542% increase and the highest level in 12 years [2]. - In New York City, the day-ahead price rose by 28% to an average of $679.13, setting a new record since 2005, with some areas exceeding $800 [2]. Group 3: Regional Power Management - The Midcontinent Independent System Operator (MISO) announced a conservative operational approach until January 29 to ensure reliable power supply for approximately 45 million people from the Great Lakes to the Gulf Coast [3]. Group 4: Negative Pricing in Chicago - In stark contrast to the price surges in the East, the Chicago electricity market experienced negative pricing, with real-time prices dropping to -$227.93 per megawatt-hour, indicating that some generators had to pay to offload electricity [4]. Group 5: Supply Constraints - The extreme cold has increased heating demand in the Midwest, but the negative pricing is attributed to full capacity on cross-regional transmission lines, limiting power exports to higher-priced markets [7]. - U.S. energy officials have requested grid operators to activate backup power sources, including data centers, to alleviate local supply constraints, but the situation is unlikely to change in the short term due to the near-maximum operation of high-voltage transmission lines [7].