AUSTIN, Texas - After a series of conservation appeals issued throughout the summer, ERCOT issued an Energy Emergency Alert Level 2 (EEA 2) that was in effect for about an hour on Wednesday, Sept. 6.
"Energy Emergency Alert 2 means that ERCOT has less than 1,750 megawatts of available capacity to deploy. That's getting us really tight. That's about 2% of demand," said Ed Hirs, energy fellow at the University of Houston. "Part of this was because coal plants were offline, some of the natural gas power plants were offline. And then there were issues with the transmission lines overheating and not being able to carry quite enough power. I mean, this is all symptomatic and a manifestation of under-investment in building a resilient grid."
According to ERCOT, the alert was issued due to a variety of factors including "high temperatures, very high demand (all-time September peak) relatively low wind output, end-of-day solar generation down ramp, and a transmission limitation in the south Texas region that restricted the flow of generation out of South Texas to the rest of the grid."
A spokesperson for ERCOT noted that to address the transmission limitation, in August, the ERCOT Board of Directors approved the formation of a planning group to "provide long-term system reliability improvements and address congestion in the South Texas region."
The project still needs to be approved by the Public Utility Commission.
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Austin Energy (AE) has a roughly 4% share of the ERCOT market. Austin Energy acts as a middleman between ERCOT and AE customers when alerts or notices are issued.
"When we receive that notice from ERCOT, we notify the city and the facilities' management over at the city of Austin so that they can communicate that to their various buildings and can mimic what we're doing at Austin Energy buildings, which is increasing the temperature of the thermostats several degrees and turning off all non-essential lighting," said Mitchell. "So if we can do that as a city entity, and we can get buy-in from other entities around the city, and specifically some of our larger customers from a commercial standpoint, then that can really reduce our load on the Austin Energy grid."
According to a spokesperson for the City, in a request for energy conservation, the Building Services Department (BSD) has the following procedures:
- Notify all Building Managers of the notice
- Ensure Building Automation Systems (BAS) are set to conserve energy as it pertains to HVAC Systems and Lighting to minimize energy use
- Ensure thermostats and lighting sensors are set accordingly (if BAS) is not in place at all sites
- Voluntary inclusion of BSD managed sites in AE Load Coop Power Saver Program that automatically raises the HVAC setpoints to minimize electric use at our core sites
- Building Automation Systems (BAS) are used to monitor and adjust building systems to maximize efficiency and tenant comfort. The systems that tie into a BAS will vary by location, but they typically include lighting, HVAC, pumps, and fire alarm systems. Temperature settings will vary by location and room type however we are able to conserve energy by raising set points, setting equipment schedules, and utilizing various sensors to reduce cooling, lighting, and electrical loads when areas are unoccupied.
If any level of energy emergency alert is issued, Austin Energy’s Commercial Demand Response (DR) program kicks in automatically.
"Commercial customers have volunteered to be a part of that…like AISD, the state of Texas, those buildings, for instance," said Mitchell. "It automatically reduces the energy load at those buildings."
Hirs noted that even with temperatures expected to go down in the coming weeks, Texans are not out of the woods just yet.
"During the fall and in the spring, a lot of these power plants go offline to perform maintenance. And we've got a lot of deferred maintenance built up in the system," said Hirs. "If we get some bad weather between here and there, we could have short supplies and go into conservation alerts."
To sign up for ERCOT’S notification system, click here.