TEXAS, USA — We're heading into the summer months, and the high heat could increase the demand for electricity as Texans look to cool their homes.
But if the demand is higher than the power grid can generate, that could spell trouble, prompting the need to move from normal operations to conservation to most dire -- a power warning.
That's where the Electric Reliability Council of Texas', or ERCOT, alert level system comes in, which displays the current conditions for the grid.
What are ERCOT's grid condition alert levels?
ERCOT has five levels of grid conditions that alert customers of the current state of power supply.
1. Normal conditions (GREEN) - There is sufficient generation
2. Conservation alert (YELLOW) - There are potentially tight operating reserves, and customers are encouraged to reduce their usage when possible
3. Power watch (ORANGE) - Consumers and businesses are encouraged to reduce their electricity use "as much as possible" from 6 to 9 a.m. and 6 to 9 p.m., to help prevent electricity emergencies
4. Power warning (RED) - Conservation is "critical" to avoid electricity emergencies or the need for rotating outage from 6 to 9 a.m. and 6 to 9 p.m.
5. Power emergency (BLACK) - ERCOT has issued rotating outages across Texas because there is not enough electric generation available. Rotating outages are "controlled, temporary interruptions of service, typically lasting 10 to 45 minutes." Customers are asked to reduce electric usage to the lowest level possible.
When do emergency operations begin?
When demand is higher than electric supply, ERCOT will begin its emergency operations to protect the grid from an uncontrolled outage. The council's emergency operations has three different levels and begin when reserves drop below 2,300 megawatts and aren't expected to recover within 30 minutes. Level 2 begins when those reserves go below 1,750 MW, and Level 3 starts when that number hits 1,375.
If reserves drop below 1,000 MW and aren't expected to go back up in the next 30 minutes, ERCOT then institutes controlled outages as a last resort, much like what Texans experienced in February and years prior.
A megawatt is enough energy to power about 200 Texas homes during peak demand, according to ERCOT.