Weather a major factor in electric demand and statewide energy alerts

Clouds over any of the major cities in Texas, like these over Houston, can significantly reduce electric demand and help prevent energy alerts.

A few weeks ago, when temperatures soared into triple digits again, a coworker asked me why the Electric Reliability Council of Texas hadn’t issued an energy emergency alert like it had the week before. I gave her a half-right answer, attributing it to more power plants providing more electricity than the week before. The more-accurate answer was weather.

The Electric Reliability Council of Texas, commonly referred to as ERCOT, manages about 75 percent of the state’s electric grid. That includes the major metropolitan areas of Houston, Dallas, Fort Worth, Austin and San Antonio. Combined, those areas make up 90 percent of ERCOT’s electric demand.

There are two variables that determine if and when ERCOT issues an energy emergency alert – how much power is needed (demand) and how much power is being generated (supply). ERCOT estimates how much power is needed and makes sure the state’s power plants are generating enough to meet demand. The state’s consumers use the electricity and can reduce the amount needed by conserving. But a major factor in how much electricity we need depends on the weather.

So, while it might be in the mid-100s from Austin to Dallas, if clouds in Houston or San Antonio hold temperatures to the high 90s, the state’s overall electric demand could be well within the available power that day. Or while the rest of the state is broiling under the hot, summer sun, afternoon thunderstorms in Dallas and Fort Worth might drop temperatures just in time for the day’s peak between 4 and 5 p.m., significantly reducing electric demand. Hence, no need for an energy emergency alert.

Of course, the flipside to that is while Central Texas might be enjoying a normal summer day in the high 90s, if Houston is enduring a hot, humid day and if the mercury in Dallas and Fort Worth is above 100, we could still fall under a system-wide energy emergency alert.

The bottom line is you can’t control the weather, but you can control how much energy you use. When ERCOT issues an alert, we can all help prevent rotating outages by using less energy.


About Will Holford

Have you ever wondered about the future of electric use? Perhaps you’re curious about how some global or national events might impact your power, the environment or your bill? Maybe you’re just interested in what’s going on at Bluebonnet Electric Cooperative. We want to share what we know, and that’s what the Bluebonnet Blog is about. Will Holford, Bluebonnet’s Manager of Public Affairs, is going to write most often for the blog. He’s been with the co-op since 2007, and has worked in communications for more than 14 years. Will enjoys learning about energy – and writing about it. He and other Bluebonnet employees (and occasional guest contributors) will get the conversation going -- about everything from where your power is generated to where it’s used, advances in technology, changes that will affect you, and interesting peeks behind the scenes at the co-op. We welcome your comments, questions and ideas. Email Will at
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