The Electric Reliability Council of Texas (ERCOT) said its demand response resources may have helped prevent a cascading power outage from sweeping across all of Texas, which as of January 7 is still hunkering down during a practically nationwide period of extreme cold.
According to the Austin American-Statesman, the operators of Texas' main power grid just barely averted a major (and unplanned) rolling blackout on the morning of January 6 when a pair of power plants in the central part of the state went offline.
A power conservation alert (a step down from an emergency alert on ERCOT's scale) remains in place as of January 7, and the grid operator is still calling for conservation.
Demand for electricity on the morning of January 7 peaked at 55,486 MW, according to ERCOT. This triggered an energy emergency alert during which the operator enacted demand response programs through entities that contract with ERCOT to shave back electricity use in extreme circumstances.
Peak cold weather times in Texas are usually in January through February. The normal peak electricity demand around that time is about 50 GW. The all-time energy demand peak for the Texas wintertime is 57,265 MW in February 2011, which coincided with a winter storm that brought 152 power plants offline in Texas, which triggered outages across the state.
ERCOT told the Statesman that the fact that only two power plants went offline during January 2014's extreme cold shows improvement.
January 6, 2014, temperatures across Texas dropped and power demand spiked as customers woke up, leading ERCOT to issue a level 1 conservation alert. Only minutes later, ERCOT went to a level 2 alert.
In a level 3 alert, ERCOT would have ordered its member utilities to rotate scheduled outages across their service territories, sparing only critical facilities such as law enforcement, hospitals and nursing facilities.
The two power plants that brought ERCOT's system to the brink of widespread blackouts were brought back online by midmorning that same day.
ERCOT has long said in its reports that electricity use in Texas is climbing faster than new power plants can be built and brought online to help meet the demand. ERCOT's grid covers about 85 percent of the state's population.
Cold weather is expected to continue across Texas until January 8 at least. ERCOT does not expect to have to resort to rolling power outages, but the operators added that the unexpected loss of power generation could make planned outages necessary to avoid an uncontrollable cascading power outage across the entire power grid.
ERCOT also had a close scrape with narrow electricity margins in December 2013, when ice storms knocked power out for about 200,000 homes and businesses — and those that still had power used a lot of it.
The power load from December 6 hit a high of 51,484 MW, passing a record set two Decembers ago. The next day, the record was broken again as power demand spike to 52,279 MW. Both times, the peak demand upon the grid arrived at about 7 p.m.
In all, ERCOT recorded three monthly power demand records in 2013.
Electric power reserves were also quite tight for ERCOT throughout the summer of 2013, which ERCOT predicted in its summer resource assessment in May of that year.
The resource assessment predicted peak demands to reach up to 68,383 MW, slightly above an all-time record set August 3, 2011.