The Electric Reliability Council of Texas is urging Texans to conserve power after a large number of power plants unexpectedly shut down in the summer heat.
ERCOT said Monday that the number of plants offline for maintenance issues was three to four times the usual number for this time of year.
The broken plants put Texas at risk of power outages again in extreme temperatures, just four months after dozens of power plants broke down in the winter cold triggering the worst electricity crisis in Texas history. The February outages left millions of Texans freezing, some even dying in their homes.
During a conference call with reporters Monday afternoon, ERCOT said it would investigate why so many plants were apparently unprepared to deal with the early summer heat.
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At 12:15 p.m. ERCOT issued an unprecedented conservation alert -- asking Texans to cut back on power not just Monday but for an entire workweek.
The alert was issued after demand for power appeared to be on track to exceed the level of supply on Monday afternoon.
“We are deeply concerned about the issues associated with these plants that are offline at this time and we will be doing a thorough investigation to understand what the issues are and to assess what the implications are for the grid,” said Warren Lasher, ERCOT senior director of system planning.
Digital Series: Powerless
Among the plants that shut down unexpectedly Monday were four that ERCOT said it recently inspected to make sure they would be ready for summer, raising more questions about whether the grid is fully prepared for the months ahead. ERCOT implemented the new summer inspections in an effort to increase public confidence in the grid.
“As Texans know, it's going to get a lot hotter before it cools down in the fall. So, we want to make sure our grid's able to handle more heat than this,” said Dr. Joshua Rhodes an energy expert at The University of Texas at Austin’s Webber Energy Group.
In recent weeks ERCOT has said the risk of power outages was less than 1% this summer and that rolling blackouts would only happen if one of several extreme scenarios occurred.
“Consumers in Texas could be very confident that these are extremely unlikely scenarios,” Lasher said in an ERCOT teleconference in early May.
But as NBC 5 Investigates has reported, some electricity experts believe rolling outages may be more likely than ERCOT imagines.
"Things that you usually think, 'I’ve got that handled. I don't need to worry about it. We do need to worry about it,'” said former Texas Public Utility Commission advisor Alison Silverstein.
Monday’s power crunch included some of the elements in ERCOT’s worst-case scenarios, including lower than expected wind power, concerns about solar power dropping off at sunset and a larger than expected number of breakdowns at traditional power plants.
ERCOT managed to avoid rolling blackouts Monday by briefly tapping into its power reserves and by leaning on Texans to cut back.
But the question now is whether those broken plants will be back in the days ahead.
“They do go down when they get stressed and heat does stress them out, but it is disconcerting to see it this early on in the summer,” Rhodes said.
ERCOT's rules prevent it from naming the plants that shut down until at least 60 days have passed. NBC 5 Investigates reached out to several large power companies Monday. Some did not respond. One told NBC 5 it could not comment on whether any of its plants were involved.
POWER CONSERVATION TIPS
- Set your thermostat to 78 degrees or higher – every degree of cooling increases your energy use by 6% to 8%.
- Turn off lights and pool pumps and avoid using large appliances like ovens, washing machines, and dryers.
- If you don’t need something, ERCOT asks you to turn it off and unplug it if possible.