As Austin was hitting record heat on June 20, the power grid that keeps air conditioners humming was running low on reserves while demand soared, the perfect combination to cause outages. An alert appealing to customers to voluntarily curb energy use kicked into action, helping reduce stress on the grid and keep power flowing.
The Electric Reliability Council of Texas, the state grid operator known as Ercot, rolled out a new alert system ahead of summer to better prepare consumers against extreme temperatures and tough conditions. Households and businesses can sign up for the Texas Advisory and Notification System, or TXANS, for email updates or download the Ercot app for mobile alerts.
Below are the levels of alerts Ercot issues to help shore up electricity supplies. The grid has soared to record levels multiple times this summer.
Read More: Why the Texas Power Grid Is Still Fraught With Risk: QuickTake
Ercot Weather Watch
This watch is issued as much as three to five days in advance of significant weather, high demand and the potential for lower reserves. It is a call to consumers to keep an eye out for further updates. Reducing electricity use during peak demand times can help consumers cut their bills and reduce grid strain.
Control room operators may issue an “operating condition notice,” or OCN, to market participants to ensure their power plants and transmission lines are ready. This would trigger an Ercot update to regulators at the Public Utility Commission of Texas.
Voluntary Conservation Notice
This notice urges changing the use of appliances or electric vehicle chargers to non-peak times. With the surge of solar generation on the state grid, the most-demand periods often are around sunset when in the summer more than 12,000 megawatts go offline and need to be replaced by fossil fuel generation. One megawatt can typically power about 200 homes.
Control Room Advisory
Ercot will issue this notice when reserves have fallen to less than 3,000 megawatts and are not expected to recover within 30 minutes. The grid operator provides another update to the PUC.
Control Room Watch
The grid is still in normal conditions, but this alert escalates the advisory. Reserves are under 3,000 megawatts and not expected to recover within half an hour. Ercot will consider a conservation alert.
Energy Emergency Alert 1 (EEA1)
Reserves have fallen below 2,300 megawatts and are not expected to recover within 30 minutes. The grid operator may consider a conservation alert here as well.
Energy Emergency Alert 2 (EEA2)
Reserves have fallen further and a conservation alert is issued. Available supply has fallen to less than 1,750 megawatts with no recovery expected within 30 minutes, or grid frequency has fallen below 59.91 hertz for 15 minutes. (Grid has to operate at 60 hertz and extended deviation can risk wider failures).
Energy Emergency Alert 3 (EEA3)
This alert triggers controlled blackouts. Power reserves have fallen to extremely low levels of less than 1,000 megawatts and are not expected to recover within half an hour or frequency has stayed below 59.91 hertz for 30 minutes.
Author: Naureen S. Malik