(The Hill) – Texas gubernatorial candidate Beto O’Rourke knocked Gov. Greg Abbott (R) on Sunday night after the state’s grid operator appealed to Texans to “voluntarily conserve electricity” during a statewide heat wave on Monday.

“The governor of the 9th largest economy on earth — the energy capital of the world — can’t guarantee the power will stay on tomorrow,” O’Rourke said in a Tweet. “We need change.”

The “conservation appeal” issued Monday by the Electric Reliability Council of Texas (ERCOT) said no major outages were expected, but asked people to consider reducing electricity use from 2-8 p.m. local time. ERCOT cited “record high electric demand” during the heatwave and low wind to power turbines as “driving the need for this important action by customers.” 

ERCOT urged Texans to turn down their thermostats and hold off on using energy-guzzling appliances or pool pumps during the six hour period.

The grid operator made a similar request in May, after six power plants shut down during a heat wave, reports the Texas Tribune.

“We can’t rely on the grid when it’s hot. We can’t rely on the grid when it’s cold. We can’t rely on Greg Abbott. It’s time to vote him out and fix the grid,” O’Rourke wrote on Twitter on Monday.

O’Rourke won the Texas Democratic primary in March and will face Abbott in the general election in November. Recent polling from the Texas Politics Project at the University of Texas at Austin shows Abbott leading O’Rourke by a six-point margin. 

The former congressman has repeatedly used the Lone Star State’s energy grid as a talking point on the campaign trail: in February, O’Rourke drove a truck across Texas to bring attention to grid-related issues.

And in 2021, he was a fierce critic of Abbot and other lawmakers for a major grid outage that left thousands of Texans without power for days amid a massive winter storm.

“We now know that the Texas government’s repeated failure to modernize our energy systems killed over 700 Texans in February’s winter storm.”

Texas Democrat Julián Castro, who was in the ring with O’Rourke as a 2020 presidential hopeful, posted a Dallas Morning News headline Monday about blackout preparations in light of the ERCOT appeal.

“Texas life these days. Thanks @GregAbbott_TX,” he wrote.

The Hill has reached out to Abbott’s office and ERCOT for comment on O’Rourke’s tweets.