The Electric Reliability Council of Texas (ERCOT) on May 3 released seasonal and 10-year outlooks that anticipate adequate generation capacity for upcoming electricity demands.
However, both the Seasonal Assessment of Resource Adequacy (SARA) and Capacity, Demand and Reserves (CDR) report identify uncertainties that could affect outcomes.
“We expect to have enough generation available to serve consumer needs this summer, based on the current forecast,” said Director of System Planning Warren Lasher. “However, hotter-than-normal weather combined with low-wind conditions or high generation outage rates could cause operating reserves to drop below target levels, making it necessary to take additional actions to maintain grid reliability.”
The final summer SARA released May 3 by ERCOT includes a peak demand forecast based on average weather patterns during the past 13 years.
“Although a transition away from El Niño adds some uncertainty to the summer forecast, we expect trends to mirror the average weather over the planning horizon,” said ERCOT Senior Meteorologist Chris Coleman. “We could see some temporary, localized hot periods, especially in the Valley and portions of West Texas, with peak demand expected later in the summer.”
The summer SARA reports 78,434 MW of total generation capacity to serve projected peak demand of 70,588 MW. This includes 680 MW of new natural gas-fired generation resources that are expected to begin operating by summer peak, 410 MW of new planned wind generation capacity (counted at 12 percent based on historical peak performance in non-coastal regions), and another 7 MW of planned grid-level solar generation capacity (counted at 80 percent during peak based on historical performance of existing resources).
The preliminary fall SARA, also released May 3, anticipates sufficient generation for the October–November period.
ERCOT’s CDR report, a snapshot of existing and planned resources and load forecasts for the next 10 years, shows planning reserve margins remaining above 15 percent through 2026, based on established reporting criteria.
“We continue to see sufficient planning reserve margins in the 10-year outlook, beginning in 2017,” Lasher said. “However, this report also includes generation resources that could be affected by environmental regulations, and future decisions by resource owners may impact these projected planning reserve margins.”
Nearly 1,000 MW of new generation added since last December
Since the previous CDR report was released in December 2015, nearly 1,000 MW of new generation has become operational in the ERCOT region, with a peak capacity contribution of about 250 MW.
Although expected generation capacity for 2017 has decreased by about 1,700 MW since the previous report, this CDR continues to show significant growth in new gas-fired generation. Based on current planning criteria, the report includes nearly 6,200 MW in new gas-fired generation by summer 2018, topping 7,400 MW in new capacity in 2020. Some of these anticipated additions could be offset by additional unit retirements that are not currently reflected in the planning horizon.
The CDR also reports continued growth in wind generation. About 11,000 MW of planned additions by 2019 would add nearly 1,800 MW in expected capacity during summer peak conditions, bringing the total expected wind contribution to almost 4,500 MW.
The May 3 CDR update includes, for the first time, a capacity contribution of 80 percent for utility-scale solar generation resources, based on historical performance of existing resources. Those resources, previously counted at 100 percent of installed capacity, are expected to contribute just under 1,400 MW during peak periods in 2017, growing to nearly 1,700 MW in subsequent years.
The next CDR update is scheduled for release in December 2016.
The summar SARA report includes a 70,588 MW summer peak load forecast that reflects the same expectations for average weather that ERCOT assumed for the preliminary SARA report. Total generation resource capacity is estimated at 78,434 MW, which includes 736 MW of planned capacity additions (about 680 MW of thermal capacity and 55 MW of renewables based on summer peak-hour ratings). As with the preliminary report, this final report reflects use of an 80% summer peak average capacity contribution for solar resources.
Capacity for two units—the PHR Peakers gas-fired plant and Baffin Wind—is excluded from the report because these facilities are now expected to be available later in the summer. Such treatment is consistent with past practice in SARA reports.
Total generation capacity also reflects 416 MW of additional mothballed capacity and a decrease of 512 MW in planned capacity relative to the amounts reported in the preliminary summer SARA report. The new mothball capacity includes the 371 MW Greens Bayou 5 unit, which is undergoing review for transmission system reliability impacts. ERCOT has initially determined that this unit may be needed for Reliability Must–Run Service. ERCOT’s final determination will be made by May 28, 2016.
The following Planned Resources (total of 3,296 MW of capacity) have finalized the necessary agreements and permits to be added to the CDR report:
- COLORADO BEND II, Wharton County, gas, commercial in 2017, 1,148 MW capacity;
- HALYARD WHARTON ENERGY CENTER, Wharton County, gas, commercial in 2017, 419 MW capacity;
- ALBERCAS WIND, Zapata County, wind, commmercial in 2016, 250 MW capacity;
- MARIAH DEL SUR, Parmer County, wind, commercial in 2017, 230 MW capacity;
- LOCKETT WIND FARM, Wilbarger County, wind, commercial in 2017, 184 MW capacity;
- PUMPKIN FARM WIND, Floyd County, wind, commercial in 2017, 200 MW capacity;
- SANTA RITA WIND, Reagan County, wind, commercial in 2016, 300 MW capacity;
- SILVER CANYON WIND A, Briscoe County, wind, commercial in 2017, 200 MW capacity;
- LOGAN’S GAP WIND II, Comanche County, wind, commercial in 2017, 200 MW capacity;
- CASTLE GAP SOLAR 2, Upton County, solar, commercial in 2017, 63 MW capacity; and
- UPTON SOLAR, Upton County, solar, commercial in 2017, 102 MW capacity.
These Planned Resources (total of 990 MW of installed capacity) have been moved to Operational Status since the release of the December 2015 CDR:
- JAVELINA WIND 18, Webb County, wind, 19.7 MW installed capacity;
- JAVELINA WIND 20, Webb County, wind, 230 MW installed capacity;
- LOS VIENTOS III WIND, Starr County, wind, 200 MW installed capacity;
- SENDERO WIND ENERGY, Jim Hogg County, wind, 76 MW installed capacity;
- SHANNON WIND, Clay County, wind, 204 MW installed capacity;
- CAMERON COUNTY WIND [CAMWIND_UNIT1], Cameron County, wind, 165 MW installed capacity; and
- OCI ALAMO 5 (DOWNIE RANCH), Uvalde County, solar, 95 MW installed capacity.