The Electric Reliability Council of Texas (ERCOT) on Nov. 2 released its final Seasonal Assessment of Resource Adequacy (SARA) for the upcoming winter season, with that report showing that two coal-fired units of Energy Future Holdings have been pulled off of seasonal operation status since the Sept. 1 preliminary SARA was issued.
With more than 79,000 MW of generation resources available, ERCOT expects to have sufficient electricity for the anticipated peak demand of 57,400 MW this winter.
“ERCOT expects to meet systemwide peak demand across a broad range of operating conditions and weather scenarios,” said Director of System Planning Warren Lasher. “Current information indicates that there would be sufficient generation available to serve the ERCOT region, even during high-load conditions with extreme generation outages.”
ERCOT’s assessment for this winter includes the same peak forecast used for the preliminary winter SARA report released in September. This reflects peak forecast expectations based on customer demand experienced during recent winter season cold-weather events and current expectations for average weather in the upcoming winter season.
“As we prepare for an El Niño-fueled winter en route to Texas, we’re forecasting December and January to be wetter than normal,” ERCOT Senior Meteorologist Chris Coleman said. “If, as expected, El Niño backs off in intensity by February, we could see a late-season cold pattern that drives temperatures lower across the ERCOT region.”
Said the Nov. 2 final SARA: “The ERCOT Region is expected to have sufficient installed generating capacity to serve forecasted peak demands in the upcoming winter season (December 2015 – February 2016). Based on the results of this study, an extreme higher-than-normal number of forced generation outages occurring during a period of unusually high demand would be unlikely to result in insufficient resources being available to serve those demands. Even if those conditions coincide with extremely low temperatures and associated capacity reductions resulting from natural gas curtailments, current information indicates that there would be sufficient generation available on a systemwide basis.
“This capacity outlook includes the same peak forecast used for the preliminary winter SARA report released September 1, 2015, reflecting our peak forecast expectations based on customer demand experienced during recent winter season cold-weather events and current expectations for average weather in the upcoming winter season. Total resource capacity also increased by nearly 1,100 MW relative to capacity reported in the preliminary winter SARA. The increase was due to the return to service of coal units previously in seasonal mothball status, as well as several wind and gas resources recategorized from planned to operational status.”
The coal units still in seasonal mothball status as of the Nov. 2 final report were Energy Future’s Martin Lake Unit 1 (815 MW) and Martin Lake Unit 2 (821 MW). The two coal units pulled off of seasonal mothball status since the Sept. 1 preliminary report were Energy Future’s Monticello Unit 1 (580 MW) and Monticello Unit 2 (580 MW).
Seasonal mothballing means that these units only run when absolutely needed, which in Texas, a summer peaking state, usually means during the summer heat when air conditioning load is high.
Incidentally, ERCOT on Nov. 2 issued a preliminary SARA for next spring that still shows the two Martin Lake units in seasonal mothball status, and the two Monticello units still out of that category.