What's behind the dangerous power outages in Texas

Millions of people in Texas remain without power as a bitter cold snap prompted record-breaking wintertime energy demand for the region, all while dozens of gigawatts of power were unavailable.

More than 4 million people in the state still don’t have power as of Tuesday morning, according to online tracker poweroutage.us. The Electric Reliability Council of Texas, or ERCOT, the Texas grid operator, said that 18,500 megawatts of power still remain offline, though it said there are plans to increase renewable energy output and return generators throughout the day to restore electricity to customers.

Over the weekend, ERCOT instituted rolling blackouts as energy demand, particularly for heating amid frigid temperatures, exceeded supply. On Sunday, the grid operator said it had set a new record for peak energy demand during the winter, 69,150 MW, more than 3,200 MW higher than the prior winter peak in January 2018. It also asked Texans to conserve energy as much as possible.

Energy experts say the problems in Texas go beyond reliance on renewable energy sources.

Wind turbines in the state froze due to the cold temperatures, taking those offline, but even more natural gas, coal, and nuclear power were unavailable. Wade Schauer, research director of Americas power and renewables at Wood Mackenzie, told Bloomberg he estimated around 27 GW of coal, nuclear, and gas weren’t available over the weekend, especially as the cold temperatures drove demand up for natural gas heating.

Energy analysts also noted that ERCOT doesn’t plan to rely much on wind power during the winter. Jesse Jenkins, a Princeton professor who is a macro-scale energy systems engineer, said ERCOT generally relies on wind for less than 10% of its total winter capacity, with the bulk being natural gas and coal.

“No matter how wind performs this week — important for future planning! — it is the big failure of the thermal plants, mostly gas units, that is causing such widespread outages now,” he said in a tweet Monday.

Texas isn’t the first state in recent months to experience power outages during an extreme weather event.

Over the summer, California’s grid operator had to impose rolling blackouts during a severe heat wave as energy demand for cooling skyrocketed at the same time there was a sharp drop-off in solar power, two natural gas units were offline, and wind power slowed down.

Many Republican lawmakers blamed California’s blackouts on its aggressive climate and clean energy policies.

Texas also has heavy renewable energy penetration, particularly wind power, on its electricity grid, but much of that has occurred due to market forces rather than policy incentives or renewable energy targets.

A particular challenge for Texas, too, is its independent power grid, disconnected from the larger regional grids for the East and the West. That island-like status makes it more difficult for the state to bring in power from other states to fill gaps in its demand.