By Tsvetana Paraskova
Renewable power generation was lower than its potential through Texas’ brutal heatwave, adding further strain to the already-battered ERCOT power grid.
-- The grid saw record electricity demand as Texans cranked up their air conditions to be the scorching heat. -- Battery storage facilities help store the generated energy and dispatch it to the grid, but much more storage capacity is needed. Wind and solar power generation in Texas was much lower than its potential during this month’s heatwave due to weather patterns, straining the Texas power grid at times of record demand. As Texans crank up air conditioners in the scorching heat, the Electric Reliability Council of Texas (ERCOT) has asked residents a few times since May to voluntarily conserve energy during peak demand hours in the afternoons and evenings.
But just when Texas needed the most of all its power generation supply, wind and solar power output was well below capacity due to a lack of wind in the high-pressure weather system and cloud cover over much of West Texas. These issues with wind and solar electricity generation highlighted, once again, the dependability of clean energy sources on the whims of weather and the unreliability of consistently dispatching large amounts of power to the grid when consumption hits records.
Battery storage facilities help store the generated energy and dispatch it to the grid when it’s needed, but much more battery storage capacity is needed in Texas—and everywhere in the world—to solve the reliability issue of renewables as a growing share of electricity is being generated by clean energy sources.
The Reliability Issue
With two more months until the end of the summer, ERCOT’s latest warning from mid-July may not be the last warning of rolling blackouts in Texas or other states across the United States. Grid operators have already warned that the electric grid reliability in some parts of the U.S. could be at risk amid high summer demand and possible supply reductions.
Texas tops the nationwide ranking of installed wind power capacity and is second only to California in operating solar capacity, according to the American Clean Power Association. Texas led the country in clean power installations in 2021, installing 7,690 MW, with California a distant second with 2,852 MW installed. Last year, Texas installed enough clean energy to fully power Delaware and Hawaii combined, the association says in its 2021 Annual Market Report.
In addition, operating wind, solar, and energy storage capacity in Texas ranks first among all U.S. states. A total of 24.6% share of all electricity produced in Texas comes from wind, solar, and energy storage power plants.
In theory, Texas has enormous amounts of wind and solar power capacity installations.
In reality, power generation falters without wind and sunshine, leaving the grid exposed to vulnerability just when it needs those renewables the most. While renewables can help the grid during mild weather and normal operations, renewables sometimes fail during peak demand and heatwaves.
This they did in the middle of July, amid record-setting extreme heat and record power demand in Texas.
Wind And Solar Power Generation Faltering
Wind power generation in Texas—America’s number-one wind power state—slumped during the heatwave that began on July 11, as wind speeds typically plunge during hot, high-pressure systems where the air above stifles winds. So the wind turbines in Texas were generating just 8% of their capacity. Meanwhile, power demand was at a record high.
ERCOT’s July 13 appeal to Texans and businesses for energy conservation noted that factors driving the need for the action by customers included: record-high electric demand, low wind generation compared to what is historically generated in this time period, forced outages in thermal generation exceeding ERCOT forecasts, and a developing cloud cover in West Texas that reduced the amount of solar generation.
On July 13, the date of the latest ERCOT call for energy conservation, the percent of dispatchable energy installed on the tightest hour was at 84%, while solar power was at 68%. Wind was at only 12% at the day’s tightest hour, per ERCOT data cited by ABC News.
“The challenge in Texas and elsewhere is on the supply side”
“The challenge in Texas and elsewhere is on the supply side,” says James Dobson, Energy Sector Strategist, CIO, UBS Americas.
“Electricity supply and demand must be equal to keep the system balanced. That’s the root of the issue. Demand is growing, yet coal plants are running less, renewables like wind and solar that can have variable output has grown significantly, so there is more strain on the supply side,” Dobson said last week.
“A utility company could invest enough to plan for one hot July day, but customers wouldn’t need those resources during other times, and it would be more expensive year round,” the strategist noted.
“We want utility companies to continue to invest in their infrastructure and have adequate supplies but there should be a cost-effective balance. Like many energy supplies around the world, there is a need to balance reliability, affordability and decarbonization, simultaneously.”
After the hottest June on record in Houston and spells of record-breaking heat across Texas in July, ERCOT’s summer troubles are not over because August could be equally hot.
Next month, a storm could change the scorching hot weather in Texas, meteorologist Matt Lanza of Space City Weather told Houston Chronicle.
“There’s a saying in Texas that droughts end in floods,” Lanza said.
A major storm or a hurricane could pose another set of challenges for ERCOT, the power lines, solar power generation in Texas, and power grid reliability.