|An Entergy Texas gas plant is shown covered in ice during a rare Arctic storm that knocked out power for millions of people across the state.
Source: Entergy Texas
A report on the deadly mid-February electric grid outages in the U.S. Southwest underscored the need to safeguard natural gas-fired power plants and related pipeline infrastructure against extreme cold weather.
The Nov. 16 report, produced by staff at the Federal Energy Regulatory Commission and North American Electric Reliability Corp., confirmed that the nearly weeklong event represented "the largest controlled firm load shed event in U.S. history."
Over a two-day period, the Electric Reliability Council of Texas Inc. lost nearly half of its available generating capacity — approximately 34,000 MW out of 68,871 MW — as natural gas production plummeted and gas-fired generators, unprepared to withstand subzero temperatures, were forced offline.
More than 4.5 million customers in Texas lost power during the event and at least 210 people died from causes such as hypothermia and carbon monoxide poisoning as residents burned fuel indoors to keep warm.
Scientists have linked the cold weather event, the fourth such event afflicting the U.S. Southwest in the last decade, to climate change-related disruptions in the atmospheric jet stream.
The 313-page joint report into the root causes of the disaster, which cost the Texas economy an estimated $80 billion to $130 billion, included 28 separate recommendations aimed at avoiding a repeat catastrophe.
NERC was already working on a new cold weather-related reliability standard when the Texas grid, which is siloed from the rest of the U.S. transmission system, was brought to the brink of collapse in mid-February.
The new standard, approved by FERC in August, requires generators to implement cold weather preparedness plans that include freeze protection measures, fuel considerations, and operating temperatures.
But the Nov. 16 report's recommendations go significantly further.
The report argued that generation owners should be required to identify and protect specific cold weather-related components and retrofit existing units with an eye toward freezing temperatures. It also said generators that experience outages due to cold weather should be required to develop corrective action plans.
Generation owners should also be required to conduct third-party inspections of freeze protection measures prior to the winter season, during the winter season, and prior to forecasted cold weather events, the report said.
The report also laid out multiple recommendations for natural gas infrastructure, acknowledging that gas-fired electric generators and gas supply infrastructure are "inextricably linked."
Given FERC's limited authority over the resilience of natural gas infrastructure, the report called on the U.S. Congress, state legislatures, and other regulatory agencies, such as the Transportation Security Administration, with jurisdiction over gas pipelines to act. In particular, it said they should consider requiring safeguards for natural gas gathering and processing equipment, such as injection facilities and flow lines.
The report also said gas-fired generators should be required to inform balancing authorities about the reliability of their gas supply contracts. Unlike most natural gas utilities that provide fuel for home heating purposes, many gas-fired generators rely on nonfirm, interruptible transportation contracts.
Balancing authorities should also be prohibited from cutting power to gas supply infrastructure in the way ERCOT did in mid-February to implement rotating grid outages, the report said. In addition, FERC should consider using its convening power to host a forum for state legislators and other regulators to discuss the potential reforms outlined in the report, staff said.
Following the mid-February storm, experts repeatedly highlighted the value associated with interregional electric transmission capacity. While electricity prices spiked in the neighboring Midcontinent ISO and Southwest Power Pool Inc. regions during the event, existing interties between the two grid operators allowed consumers in their multi-state footprints to avoid the same widespread blackouts experienced in Texas.
The report said ERCOT, which only has 1.2 GW of synchronous direct current transmission ties with SPP and Mexico, should evaluate the befits of additional interconnections with the Western and Eastern Interconnections in the U.S.
A study released in July by the American Council on Renewable Energy estimated that consumers in Texas would have saved nearly $1 billion for each additional GW of transmission ties between ERCOT and the neighboring Tennessee Valley Authority transmission system.
FERC Chairman Richard Glick has signaled openness to explore ways for ERCOT to establish additional interconnections with the rest of the U.S. grid while largely remaining exempt from the commission's jurisdiction.
The Public Utility Commission of Texas unanimously passed a new weatherization standard for power plants in October that requires generation and transmission owners within ERCOT to attest by Dec. 1 that they have prepared infrastructure for the upcoming winter. Such companies must fix any "known, acute" issues that occurred in the February freeze.
An ERCOT spokesperson said in a Nov. 16 email that the grid operator has already made "significant progress" to ensure that the Texas power system performs "significantly better this coming winter than in the past."
"For all the major electric-related issues and recommendations identified in this report, we are confident they are already being addressed in actions taken or underway by the Texas Legislature, Public Utility Commission, or ERCOT," the spokesperson said.