By Tom Kleckner

ERCOT’s seasonal assessments of resource adequacy (SARA) for the fall and winter predict enough generation available to serve forecasted peaks.

The Texas grid operator’s fall SARA shows 77,289 MW of generation available this October and November, more than enough to meet its expected peak of 49,709 MW.

According to the preliminary winter SARA, ERCOT will have 78,253 MW available to meet a projected peak demand of 57,400 MW from December through February 2016. A final winter assessment with an updated weather forecast is scheduled for release Nov. 3.

ERCOT said it expects reserves to range from about 3,600 MW — should peak demand be significantly higher than expected — to nearly 15,000 MW under expected conditions.

“We’ve captured a wide range of scenarios,” said ERCOT’s Pete Warnken, manager of resource adequacy, in response to RTO Insider. “Based on our most recent scenarios, we feel very comfortable with our forecasts.”

ERCOT said it will “continue to monitor the potential effect of Texas’ future drought conditions on generation capacity and ongoing changes to environmental regulations.”

850 MW Additional Capacity Online

ERCOT has added 850 MW of installed capacity since its preliminary fall assessment was published in May, thanks to a combined-cycle generator and three wind projects. Another 1,058 MW of wind projects have been delayed beyond Oct. 1, and will no longer contribute to the fall’s expected capacity.

ERCOT senior meteorologist Chris Coleman said he expects average fall weather despite unusual weather patterns associated with warm ocean temperatures.

Coleman said El Niño this year could be the strongest since 1997, leading to colder, wetter and cloudier winter weather. He said it could also lead to more wind power generated. ERCOT generates about 1,000 MW of wind power during the winter and exceeds 4,000 MW during the summer.

The peak forecast is based on normal weather conditions for 2002-2013 during peak maintenance periods.

ERCOT’s all-time winter peak of 57,265 MW, set in February 2011, was nearly matched in January 2014. The 2014 conditions are reflected in the extreme scenarios included in the winter assessment.

One megawatt powers about 500 homes in Texas during mild weather conditions and about 200 homes during summer.