By Megan Menchaca and Mitchell Ferman | Texas Tribune

Gov. Greg Abbott issued a disaster declaration Friday afternoon for every county in Texas as a massive winter storm threatens to wreck havoc on the state’s electricity grid, power lines and roads.

“Texas should heed the guidance of their local leaders and stay alert to changing weather conditions in their area,” Abbott said in a press release.

The state’s power grid could see record-setting winter electricity demand from Texans trying to keep warm this weekend. That means the capacity of Texas’ power grid, most of which is run by the Electric Reliability Council of Texas, will be put to the test. It is unclear whether this will result in rolling blackouts in Texas, or “rotating outages” as ERCOT calls system power outages.

“We’ve got maybe seven days of some real serious stress here,” said Ed Hirs, energy economist at the University of Houston.

Abbott’s order comes as the National Weather Service issued winter storm warnings or watches for most of the state. The freezing weather is expected to last through the weekend and into Monday evening. The Dallas-Fort Worth and Central Texas areas could see light ice and snow accumulations of 3 to 6 inches, according to a warning.

Some areas have already experienced power outages or icy roads. In Fort Worth, more than 130 vehicles were involved in a deadly highway pile-up on Thursday.

The North Texas warning said the wind chill is expected to dip as low as minus 15 degrees. The service is also predicting record-low, single-digit temperatures across much of Texas over the coming days. The forecast of 6 degrees on Tuesday in Austin would be the coldest low since December 1989, according to the Austin American-Statesman.

“Travel will be dangerous,” the National Weather Service alert said. “Hazardous conditions will persist for several days given the expected prolonged duration of extremely cold temperatures. The cold wind chills as low as 15 below zero could result in hypothermia if precautions are not taken.”

In the declaration, Abbott wrote that the weather would pose an “imminent threat” of property damage, injury and loss of life due to the freezing temperatures, snow and rain.

Abbott ordered the Texas Division of Emergency Management to deploy a variety of state resources, including through the Texas Department of Transportation to prepare roads, the Texas Highway Patrol to help stranded drivers and the Public Utility Commission to monitor and report power outages.

Power grid regulators are expecting demand for electricity in the coming days to hover just below the record demand typically seen in the summer, when Texans crank their air conditioning to cool off. But the Texas electricity market is set up for summer electricity demand. It is not set up for the winter, experts say.

Extra generators — such as natural gas plants — are up and running to support the heightened power demand during the Texas heat.

Some of those energy sources are offline during the winter, when electricity demand is not usually rivaling that of the summer months, according to Hirs, the energy economist. And freezing temperatures have left many farms of wind turbines dormant as operators deal with idling icy blades.

ERCOT spokeswoman Leslie Sopko urged Texans to follow the agency’s twitter page and website for updates on the grid’s condition.

Companies that deliver wholesale energy to households and businesses are bracing for emergencies. They are keeping crews stationed across the state through the weekend when crews would instead normally return home.

The Texas branch of American Electric Power, called AEP Texas, delivers energy to more than 1 million Texas homes and businesses throughout southern and western Texas. Larry Jones, a company spokesman in Austin, said rolling blackouts are a last-resort designated by ERCOT.

“We would issue rotating outages throughout parts of our service territory,” Jones said Friday. “Those can last anywhere from 45 minutes to an hour. You can rotate them in the effort to minimize the impact on customers.”

If an outage occurs, Jones said, AEP Texas typically tells customers to turn off major electronic devices in their home, such as laundry machines and heating and ventilation units.

“This is going to show people the difference between a cold snap and a cold spell,” Andrew Barlow, director of external affairs for the Public Utility Commission of Texas, an agency that provides oversight of ERCOT, said of the upcoming weather. “Texans are used to having our normal mild winter weather — one day below freezing, maybe a dusting of snow, some ice. But the weather models are showing this thing could linger for two or three days. That takes you from a snap to a spell.”