By Tom Kleckner

It had been four years since ERCOT last set a new demand record, but the Texas grid has been making up for lost time since August began. In the last two weeks, ERCOT has set three new hourly peaks, topping 69,000 MW in demand for the first time ever on Aug. 10.

ERCOT says while the summer temperatures are partly attributable to the increase, the state’s explosive population growth is the real driver.

“A large part of the demand we’re seeing is customer growth over the last few years,” said ERCOT COO Brad Jones last week.

Jones made his comments a few hours after ERCOT issued a conservation alert and asked customers to limit electricity usage during the 3-7 p.m. peak-demand hours Aug. 13. Triple-digit temperatures and outages at several power plants brought the ERCOT system perilously close to its 2,500-MW reserve threshold.

The system set a new all-time peak hourly demand Aug. 10 when it eclipsed the 69,000-MW mark for three consecutive hours, hitting a record 69,783 MW between 4 and 5 p.m. Operating reserves remained above 3,000 MW during the day, Jones said.

ERCOT previously set demand records Aug. 6 (68,912 MW) and Aug. 5 (68,459 MW). Until then, the ISO’s previous record was 68,305 MW, set Aug. 3, 2011.

At this pace, ERCOT will surpass August 2011’s record production of 38.2 GW of energy.

Jones said ERCOT imported power through its two links with SPP but avoided calling for load curtailments or other emergency operations thanks to conservation by consumers. Market prices jumped to about $1,700/MWh during the day.

Population Growth

The U.S. Census Bureau says Texas’ population has grown by 1.8 million people from 2010 to 2014, a 7.2% increase. The state’s population — almost 27 million at the end of 2014 — is expected to double by 2050.

According to the state comptroller, more than 100,000 single-family building permits and 64,000 multi-family permits have been issued in the 12 months ending June 2015.

The comptroller also said Texas’ real gross domestic product grew by 5.2% in 2014, compared with 2.39% for the U.S. The state’s unemployment rate was 4.2% in June, down from 5.0% in June 2014; it has been at or below the national average for 102 consecutive months.

Jones noted ERCOT serves some of the fastest-growing cities in the country. Houston, San Antonio, Dallas, Austin and Fort Worth are among the 16 most populous cities in the U.S.

Some 4,800 MW of new generation will be coming online in the next three to four years, Jones said.

ERCOT said it will continue to monitor conditions as summer demand continues and call for conservation when needed. It has asked Texans to raise thermostats 2 to 3 degrees during peak hours, use fans, limit the use of large appliances to off-peak hours and close blinds and drapes during the afternoon.

“Voluntary conservation can help us reduce the potential for additional measures, such as rotating outages, to ensure reliability throughout the ERCOT grid,” said ERCOT’s Director of System Operations, Dan Woodfin, in one of many press releases the ISO has issued this month.

SPP: Hot, but not Breaking Records

The SPP footprint has seen some of the same triple-digit figures as Texas, but the RTO has not topped its record demand peak of 54,949 MW, set Aug. 3, 2011. Its high for the year came in July, when the SPP Balancing Authority recorded a peak of 45,873 MW.