The imprudence is chilling. From that doc: "THE EVENT The strong arctic front that arrived in North Texas on February 1, 2011 was the most intense cold wave f

The imprudence is chilling. From that doc: "THE EVENT The strong arctic front that arrived in North Texas on February 1, 2011 was the most intense cold wave for the majority of the state of Texas since December 1989. The event was so severe that the National Weather Service issued a rare Wind Chill Advisory for much of the state. The arctic front reached deep into Texas and sustained below freezing temperatures as far south as Corpus Christi. Much of North Texas experienced record setting sleet and snow, producing blizzard conditions and temperatures well below freezing for up to 100 hours. Snowfall occurred as far south as San Antonio, with snowfall totaling up to seven inches in North Texas. This winter storm was also accompanied by sustained winds of 30-40 mph with gusts as high as 51 mph. The icy conditions of this winter storm resulted in the closing of both DFW Airport and Dallas Love Field. In addition, Dallas-Fort Worth area water utilities reported hundreds of water main bursts during the event, compared to expected four to five on an average winter day. ERCOT also reported a new record winter peak of 56,334 megawatts. The winter weather event of February 1-5, 2011 was determined to be a one in ten year event for some regions of Texas in terms of low temperature extremes and duration. Lows during the period were in the teens for five consecutive mornings and there were many consecutive hours below freezing temperatures throughout Texas. Taking these temperature extremes into account, and coupling them with the sustained winds of this event, it is estimated that the resultant convective heat loss (wind plus ambient temperature) event suffered by many Texas generation facilities approached a one in 25 year severity. (Reference: Weatherbank, Inc.) Generating unit issues that affected reliability were mostly attributed to frozen instrumentation due to convective heat losses greater than instrumentation design, faulty instrumentation heat tracing or compromised insulation. It is normal practice for the operating units to add incremental protection against these extreme winter weather events. Typical examples are wind breaks and heat sources applied to high risk areas. In addition, the cold and wind affected the units that were not operating. Units in cold start status are less prone to derates/trips if they are dispatched to minimum stable load (MSL) before the onset of extreme winter weather. Bringing all units to MSL gives ERCOT maximum flexibility in responding to grid emergencies. HOW IT AFFECTED ERCOT The high load demand, coupled with generation issues within ERCOT, resulted in actions from ERCOT that triggered an Operating Condition Notice (OCN) issued for cold weather at 08:55 on February 1. The event level escalated to an EEA2A (Energy Emergency Alert) declaration at 05:18 on February 2 to deploy responsive reserves, followed quickly by an EEA3 declaration at 05:58 on February 2 to begin shedding firm load to maintain system frequency at 59.8 Hz or greater. The event continued until ERCOT cancelled the EEA at 09:58 on February 3. "