Summer Grid Alerts: What Conservation Appeals Mean

What Triggers a Grid Alert

Every summer, Texas air conditioning pushes electricity demand toward the grid’s limits. When the gap between available supply and expected demand gets too small, ERCOT issues alerts to let the public and grid operators know that conditions are tightening.

The triggers are straightforward. ERCOT maintains operating reserves — extra generation capacity that can be called on quickly if something goes wrong. When those reserves shrink below certain thresholds, alerts escalate. The most common causes are:

• Extreme heat. When temperatures stay above 100 degrees across most of the state, AC demand can push past 80,000 megawatts.
• Low wind output. Texas has massive wind generation, but on calm summer afternoons, wind farms may produce very little.
• Generator outages. Power plants sometimes trip offline unexpectedly due to equipment failures.
• Cloud cover. Widespread clouds can reduce solar output at critical times.

The Alert Levels

ERCOT uses a tiered system of alerts, each representing a different level of grid stress:

Weather Watch

A weather watch means ERCOT forecasts tight conditions in the coming days. It is a heads-up, not an emergency. Grid operators start preparing by lining up additional resources and coordinating with generators.

What you should do: Nothing immediate. Be aware that conservation appeals may follow in the coming days.

Conservation Appeal

This is the most visible alert. ERCOT asks Texans to voluntarily reduce their electricity use, typically during afternoon and early evening hours (2 PM to 8 PM) when demand peaks. Common requests include:

• Set your thermostat a few degrees higher
• Avoid running large appliances like washers, dryers, and dishwashers during peak hours
• Turn off unnecessary lights
• Postpone pool pump operation to nighttime hours

What you should do: Follow the conservation guidelines. Every little bit helps. If millions of Texans each reduce their demand slightly, it has a meaningful impact on grid reserves.

Energy Emergency Alert Level 1 (EEA1)

EEA1 means operating reserves have dropped below the minimum threshold. ERCOT activates all available resources, including emergency demand response programs and power imports through DC ties to neighboring grids.

What you should do: Reduce your electricity where you can. This is more serious than a conservation appeal, though power is still on for everyone.

Energy Emergency Alert Level 2 (EEA2)

EEA2 means reserves continue to fall. ERCOT may ask large industrial customers enrolled in curtailment programs to reduce their load. Public appeals to conserve become more urgent.

What you should do: Minimize your electricity as much as possible. Charge phones and devices in case of outage. Have flashlights and water accessible.

Energy Emergency Alert Level 3 (EEA3)

EEA3 is the most severe level and means ERCOT has ordered rotating outages (controlled blackouts) to prevent a total grid collapse. This is extremely rare during summer.

What you should do: If your power goes out during rotating outages, it is temporary and usually lasts 15-45 minutes before rotating to another area. Do not call 911 unless there is an actual emergency. Report outages to your TDU.

How Conservation Actually Helps

It is easy to feel like turning off a few lights does not matter when the grid needs thousands of megawatts. But the math works. If 10 million Texas homes each reduce demand by 0.5 kW (the equivalent of raising the thermostat 2-3 degrees and turning off a few things), that equals 5,000 megawatts — enough to make the difference between a stable grid and rolling blackouts.

Demand response programs amplify this effect. Many utilities and REPs offer smart thermostat programs that can automatically adjust your AC by a degree or two during grid emergencies in exchange for bill credits. These programs collectively represent thousands of megawatts of flexible demand.

Preparing for Summer

A few steps can make summer grid alerts less stressful:

1. Have a plan for outages. Keep flashlights, batteries, and a charged portable power bank handy. Fill water containers in case water pressure drops.
2. Pre-cool your home. On forecast high-demand days, set your thermostat lower in the morning before peak hours. Your home acts as a thermal battery.
3. Shift your heaviest electricity to off-peak hours. Run your dishwasher, laundry, and other major appliances in the morning or late evening.
4. Enroll in demand response. If your REP or TDU offers a smart thermostat program, the bill credits add up and you help the grid at the same time.

The Bottom Line

Summer grid alerts are part of life in Texas, but they rarely lead to actual outages. Understanding the alert levels helps you know when to act, what to do, and how your small contributions to conservation add up to keep the grid stable for everyone.