Texas Grid Nears Crisis Conditions Before Summer Even Arrives

Officials at the Electric Reliability Council of Texas (ERCOT) weren’t able to even make it to the first official day of summer this year before having to issue a voluntary conservation notice to Texans, as the state’s electricity grid came perilously close to being unable to meet high demand on June 20.

“ERCOT has issued a Voluntary Conservation Notice for today, June 20, from 4 p.m. to 8 p.m., and controlled outages are not needed at this time,” the notice, updated at 3:57 p.m. CST, began. “ERCOT is not in emergency operations. Texans are being asked to voluntarily reduce electric use, if safely able to do so.”

As of 4:49 p.m., ERCOT said system-wide demand had exceeded 79,000 MW, an all-time record high for the date, leaving the system with less than 5,000 MW of reserve available generation capacity. The tight conditions come in the midst of a heat wave that had been forecast by weather services for well over a week in advance, so the conditions should have come as no surprise to grid operators.

Although ERCOT’s explanation for the notice claimed that more thermal generation was offline for repairs and maintenance than normal at this time of year, as of 4:49 p.m., almost 58% of generation on the grid was being provided by natural gas, with another 15% coming from coal and lignite. At the same time, the state’s vaunted wind fleet, which boasts a nameplate capacity of over 38,000 MW, was providing just 4,700 MW, or 6% of total system load. Solar, which has accounted for the vast majority of recent capacity additions to the grid, was far exceeding wind’s contribution at 11,188 MW, or 14.2%.

ERCOT’s difficult final day of Spring came 6 weeks after its officials, along with Texas PUC Chairman Peter Lake, issued a report warning Texans that, while the general assessment was that the grid had adequate existing capacity, it could run into capacity adequacy issues under certain conditions during the summer.

Lake, who resigned as PUC chairman on June 2 after some of his legislative priorities were rejected by the state legislature, said at the time, “On the hottest days of summer, there is no longer enough on-demand dispatchable power generation to meet demand on the ERCOT system.” Lake added that the shortage has come about since 2008, as power generators in the state have chosen to add just 1.5% of additional thermal capacity while the state’s population grew by 24%.

The other big problem ERCOT experiences during the heat of Texas summers is that the wind tends to die down as demand on the system peaks in the late afternoon. Given that very little stationary battery capacity exists to back up renewables in Texas (as shown in the chart above), this means wind fails to deliver when the capacity is most needed, which is a common issue with wind in general.

What this all emphasizes yet again is that the Texas grid is desperately in need of more dispatchable thermal capacity that is available to ramp up and take the load when renewables fail to deliver during times of severe weather. Fortunately, the legislature did choose to pass legislation to incentivize the building of such new capacity with tax abatements and completion bonuses in this year’s session. Less fortunate is the likelihood that it will take several years before the new capacity is built and can be integrated into the grid.

In the meantime, ERCOT officials will be likely to experience more difficult days like they did on June 20. As a Texan, I wish them good fortune in their efforts.