Operating electric power reserves for Texas still look tight for this summer on growth in the Permian Basin and along the Gulf Coast, but they have improved in the past three months thanks in part to the return of a 365 MW natural gas-fired unit, according to the power grid that oversees flows to 90% of the state’s customers.
The Electric Reliability Council of Texas, aka ERCOT, on Wednesday issued its final Seasonal Assessment of Resource Adequacy (SARA) for June through September, following a preliminary review in March. The grid operator also published a preliminary fall assessment and an updated report on Capacity, Demand and Reserves (CDR).
The planning reserve margin for this summer has increased to 8.6% based on the resource updates incorporated in the final report. In addition to the gas-fired unit coming online, more output is expected from equipment upgrades and from additional direct current tie imports.
The above-normal system-wide growth is rising at a rate of 2.5-3% through 2020, lifted by West Texas oil and gas expansions, as well as the numerous industrial complexes underway on the Gulf Coast.
“In all of the scenarios studied for the final summer SARA, ERCOT identified a potential need to enter Energy Emergency Alert status in order to maintain system reliability,” it said. The final summer SARA still expects peak demand to remain the same as projected in March at 74,853 MW, which is 1,300 MW higher than the all-time record set on July 19, 2018.
Operating reserves are expected to remain tight, but total generation resource capacity has increased to 78,929 MW from the preliminary report. In addition, the planning reserve margin for summer has increased to 8.6%.
The updated CDR calculated higher planning reserve margins between 2020 and 2023, primarily because more potential wind and solar projects are in the interconnection queue and would be eligible to be included.
Since the CDR was issued in late 2018, 733 MW of installed wind and solar capacity have been approved by ERCOT for commercial operations, with summer peak capacity contributions of 333 MW. Twenty-two distributed generation solar units totaling 143 MW also were added to the report with a combined capacity contribution of 106 MW.
In the preliminary SARA for this fall (October and November), ERCOT is forecasting enough resource capacity to serve estimated peak demand of 61,034 MW.
The total resource capacity expected to be available for peak demand is 84,125 MW, including planned capacity additions of 1,485 MW. The additions include 207 MW of gas-fired generation (based on fall ratings), 2,909 MW of wind with a fall peak capacity contribution of 1,084 MW and 304 MW of solar with a fall peak capacity contribution of 194 MW.
This preliminary fall SARA report includes a unit outage forecast of 13,833 MW based on the historical average of outages for weekday peak hours for each of the fall seasons in 2016 through 2018.