AUSTIN, Texas — Leaders at the Electric Reliability Council of Texas (ERCOT) say they must stay flexible as Texas heads into winter.
”Flexibility is becoming the most— one of the most— important attributes of a reliable grid in today's construct," Pablo Vegas, ERCOT’s President and CEO, said Tuesday in the Board of Directors meeting. "And that's not just in Texas. It's all throughout the U.S. and throughout the world, because flexibility is critical to manage the different drivers of change that are going on on the grid."
Vegas said the state's overall electricity consumption continues to change. Texans broke the record for electricity used 10 times over the summer.
On Sept. 6, ERCOT reached the second level of emergency operations. It was the tightest supply and demand on the electric grid since the February 2021 deadly winter storm. Level 3 would have started rolling blackouts.
“It's not just the intermittency of certain, you know, renewable sources. It's not just the dynamic nature of the types of loads and large loads that are coming onto the system. It is all of those factors combined together, and in addition, a growing resource and energy storage resources, which are a tremendous value to the grid and that we are learning how to leverage more effectively,” Vegas said.
Record heat led Texans to use more electricity to cool homes and businesses. Vegas said a shift in the peak demand also impacted how they predict supply and demand.
“We experienced some meaningful change in terms of when the scarcity period shifted from just a year ago. At the same time last year, the scarcest period of time during the summer was during the gross peak on the system, which was around three or 4 p.m. in the afternoons in the summer when the heat is at its maximum and demand is at its highest. We saw a change this year where that scarcest and tightest period actually shifted to later in the day to seven or 8:00 at night as we were going through the solar ramp,” Vegas said.
Vegas said the addition of solar resources over the last year contributed to that shift, too.
“We ended up having scarcity later in the day on the hot days when the heat remained into the evening and we started to lose the energy from solar resources, that became the new scarcest and tightest period on the ERCOT grid. And that shift occurred for the first time this year,” Vegas said.
Vegas said the demand was consistently higher with 49 days requiring more than 80 gigawatts. For comparison, Vegas said demand reached 80 gigawatts for one day in 2022 and zero days in 2021.
The current peak record demand was set on Aug. 10 at 85,464 megawatts (85.4 gigawatts).
“The system was clearly stressed and stretched, but it held,” Vegas said.
Traditionally, ERCOT produces a seasonal assessment of resource adequacy reports. Now, the grid manager will produce a monthly prediction released on the first of each month or the first business day if the beginning of a month falls on a weekend or holiday.
“We have moved that now to a monthly process which allows us to be more granular and closer to the period in which the operating conditions will be occurring," Vegas said. "And we're also focusing on being more granular when it comes to the risk assessments on an hourly basis."
The first report, released this month and updated on Oct. 10, shows expected resource adequacy for December.
“We don't get the benefit of what has been one of the fastest growing resources on the grid, which is solar energy resources during the winter peaks,” Vegas said.
Heading into winter, ERCOT issued a Request for Proposal (RFP) to secure an extra 3,000 megawatts of reserve power.
“If we think there could be a risk of emergency operations, then we can issue an RFP to procure capacity, both supply capacity and/or demand response capacity and so it's open to both. On the supply side, it really is focused on capacity that has either recently retired or recently mothballed that could potentially come back. Then on the energy, on the demand response side, it's really open to any net new demand response that could be made available during that season. That could be at the consumer level all the way up to the industrial level,” Vegas said.
Vegas said ERCOT used the cold weather from Dec. 22–25, 2022, as a metric for an “extreme” winter condition. ERCOT’s winter storm report shows Texas reached more than 74,000 megawatts and set a new winter peak demand during the Dec. storm.
Vegas told board members a new weatherization standard will be in effect this winter, too.
The new standards include, “additional weather emergency preparation measures reasonably expected to ensure sustained operation at 95th percentile minimum average 72-hour wind chill value in ERCOT weather study for facility’s weather zone,” ERCOT records show.
Power entities must also create a list of critical components.
“Those standards apply to geographic parts of Texas, to specific geographies, and have actual temperature resiliency requirements for transmission and generation operators in each of those regions. So as we do inspections, the requirements against that we are going to be inspecting, we’ll be looking at those specific requirements for the geography. So if a unit or a power plant is up in the northern part of Texas, it'll have to be able to withstand colder temperatures because of that geography than a power plant would down in the Corpus Christi area of Texas,” Vegas said.
Also, starting Nov. 1, ERCOT will initiate rolling blackouts should the reserves hit less than 1,500 megawatts.
“This Nodal Protocol Revision Request (NPRR) revises the Energy Emergency Alert (EEA) procedures to require a declaration of EEA Level 3 when Physical Responsive Capability (PRC) cannot be maintained above 1,500 MW and will require ERCOT to shed firm Load to recover 1,500 MW of reserves within 30 minutes. This NPRR also modifies the trigger levels for EEA Level 1 and EEA Level 2, changes the trigger for ERCOT’s consideration of alternative transmission ratings or configurations from Advisory to Watch when PRC drops below 3,000 MW, and restores a frequency trigger for the declaration of EEA Level 3 if the steady-state frequency drops below 59.8 Hz for any period of time,” the rule change shows.
The NPRR was approved Oct. 12 by the Public Utility Commission of Texas (PUC).
On Friday morning, PUC will hold a meeting to discuss winter preparations. ERCOT and companies operating in the electric power market are expected to participate. The meeting will also be streamed online for the public.