The Electric Reliability Council of Texas (ERCOT), grid operator for most of the state, expects the region will have sufficient electric supplies this winter, based on a broad range of planning scenarios in the Seasonal Assessment of Resource Adequacy (SARA) released today.
Generation resources for this winter in the ERCOT region total more than 77,350 MW. The forecast, based on 12-year average winter temperatures, projects peak demand at about 53,000 MW. One MW is enough electricity to serve about 200-500 homes, depending on weather conditions.
Under the full range of planning scenarios, available ERCOT reserves during this winter’s peak could range from more than 16,000 MW to less than 1,200 MW, with the latter representing a worst-case scenario of very high demand, extensive generation outages, and fuel supply limitations that would further reduce generation capacity. In that scenario, peak demand could exceed 59,640 MW, more than 2,000 MW higher than the 57,265 MW winter record set in February 2011.
“In recent years, generation providers in the ERCOT region have improved their procedures to prepare their facilities for extreme winter conditions,” said Ken McIntyre, vice president, Grid Planning and Operations. “We continue to monitor these efforts to help assess the preparedness of the system overall.”
In addition to new resources that began operations in 2014, the increase in generation capacity also reflects a change in the percentage of installed wind power capacity that ERCOT expects to be available during peak demand periods. A new methodology, approved by the ERCOT Board of Directors on Oct. 14, enables ERCOT to project wind energy availability based on location (coastal or non-coastal) and historical performance during seasonal peaks.
The winter SARA includes coastal wind generation at 36 percent of installed capacity and non-coastal at 19 percent, bringing the expected peak average wind capacity contribution to nearly 2,500 MW.
ERCOT continues to caution residents in the Lower Rio Grande Valley of potential reliability challenges as transmission providers work to improve the system that serves that rapidly growing region. The SARA is a systemwide assessment and does not reflect this localized issue.
Based on input from generation owners, ERCOT does not expect drought conditions or coal transportation issues to affect generation availability during periods of peak demand this winter. To date, ERCOT also has not received reports from generation owners of expected capacity changes associated with U.S. Environmental Protection Agency’s potential implementation of the Cross-State Air Pollution Rule, which could be in place in January 2015.
Although generation owners likely will wait for additional guidance from the EPA, ERCOT believes it is reasonable to expect some coal-fired units to reduce operations to comply with the new rule and will continue to monitor these developments.
ERCOT today also released a preliminary SARA for spring 2015, which currently projects adequate resources to meet expected demand. The final spring assessment is scheduled for release Feb. 27, 2015. ERCOT also plans to release its next Capacity, Demand and Reserves report, with an updated 10-year outlook, on Dec. 1.