HOUSTON (AP) — Texas’ power grid has been under tremendous stress during this summer’s sweltering heat, with the state setting 10 new records for electricity demand.

The grid's reliability has been questioned by residents and lawmakers since a deadly winter blackout in 2021 knocked out power to millions of customers for days and resulted in hundreds of deaths.

Concerns were renewed this week after Texas’ power grid manager issued an emergency alert due to low reserves and high demand. Following the alert, the U.S. Department of Energy granted an emergency order allowing Texas to temporarily suspend emissions rules so power plants could produce enough electricity to prevent outages.

The summer heat isn’t subsiding as high temperatures above 100 degrees Fahrenheit (37.8 Celsius) were expected in much of Texas through the weekend.

This summer’s challenges have raised more questions about the power grid’s reliability and what more the Electric Reliability Council of Texas, the grid manager, should do to shore it up.

WHAT HAS TEXAS DONE SINCE THE 2021 BLACKOUT?

Significant changes included mandates for plants to weatherize for the cold. Texas lawmakers also passed bills this year aimed at providing incentives for the development of more “on-demand” generation — not including renewables like wind or solar — to keep up with the state's fast-growing population. But it’s not clear whether that will entice companies to build.

Republican Gov. Greg Abbott has declared the changes have fixed “all of the flaws” that caused one of the largest power outages in U.S. history. But skepticism remains.

Energy experts say Texas isn’t doing enough to ease demand on the system. When a bill to increase energy efficiency in new construction reached Abbott’s desk in June, the governor lumped it in with other vetoes while trying to pressure lawmakers into reaching a deal on property tax cuts.

HOW HAS THE SUMMER HEAT IMPACTED THE POWER GRID?

Record power demand and other problems culminated this week when ERCOT issued a level 2 energy emergency alert, bringing Texas the closest it has been to statewide outages since the 2021 winter storm. ERCOT said it issued the alert because operating reserves fell as demand surged and power from wind and solar energy sources proved insufficient. It also cited another cause: congestion on a transmission line that prevented the flow of power from South Texas to the rest of the grid.

The increased stress on the power grid has prompted ERCOT to ask customers 10 times in the last three weeks to cut their electricity use.

“These high temperatures are driving record demands for this time of year,” Pablo Vegas, ERCOT’s president and CEO, said in a Wednesday letter to the U.S. Department of Energy that asked for the temporary suspension of emissions rules.

U.S. Energy Secretary Jennifer Granholm granted ERCOT’s request, writing Thursday in a letter that the threat of power loss to homes and businesses in Texas is “presenting a risk to public health and safety.”

Texas has never had forced outages in summer months since ERCOT was created in the 1970s, according to the grid operator.

WHAT ADDITIONAL IMPROVEMENTS CAN TEXAS MAKE TO SOLIDIFY THE GRID?

Doug Lewin, an Austin, Texas-based energy consultant who writes the Texas Energy and Power Newsletter, said improvements could include using grid enhancing technologies that allow for more electricity to flow on transmission lines and additional battery storage of electricity. He said battery storage likely helped prevent outages this week.

Lewin also called on ERCOT to prioritize programs that would pay residential and small business consumers to use less electricity. Such programs already exist for big power users like manufacturers and cryptocurrency miners. On Wednesday, Riot Platforms, a bitcoin mining company, said it received $31.7 million in energy credits in August from ERCOT for reducing its energy usage.

“They want to compensate me for (using less energy), I’ll participate. But I’m not doing it uncompensated while Riot Platforms is getting paid millions of dollars. No, like pay me for it,” Lewin said.

ERCOT also needs to be more open about its operations, Lewin said, adding that questions remain about the grid operator's explanation on what caused this week's emergency alert, including whether low wind generation was a factor.

“I sometimes criticize ERCOT and (the Public Utility Commission of Texas) and the only reason I do it is because we all need them to be successful," he said. "And I think the only way to be really good at a job like that is to be open, honest, transparent to a fault.”

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Associated Press writer Paul J. Weber in Austin contributed to this report.

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