By Tom Kleckner
ERCOT’s latest seasonal forecasts indicate the ISO will continue to have more than enough generation capacity to meet demand into next summer, continuing a recent pattern of rosy forecasts.
According to the winter Seasonal Assessment of Resource Adequacy (SARA), ERCOT expects to have almost 82,000 MW available December to February, more than enough to meet an anticipated winter peak of 58,000 MW. That would exceed the ISO’s winter peak record of 57,265 MW, set in February 2011.
The preliminary spring SARA (March-May) also projects nearly 82,000 MW of available capacity and a seasonal peak of 58,000 MW in May. The assessment takes into account the expected spring generation outages for routine maintenance; the final spring SARA report will be released in March.
Asked about the recent positive forecasts, ERCOT Senior Director of System Planning Warren Lasher said, “I believe we’re in a period right now where we have adequate resources. The emphasis here is proving that assessment back to consumers.”
“We’ve added resources, but we’ve also modified our load forecast methodology,” said Pete Warnken, ERCOT’s manager of resource adequacy. “I believe it’s a more accurate, more on-target forecast.”
Lasher and Warnken both cautioned that continued congestion in the Lower Rio Grande Valley, which resulted in conservation calls in early October, remains a subject of concern. The 524-MW Frontera combined cycle plant’s withdrawal from the ERCOT system Oct. 1 to dispatch into the Mexican market has complicated the task of meeting demand along the U.S.-Mexico border.
“Our current expectation is we won’t have a similar call for conservation,” Lasher said.
Weather is not expected to play a factor this winter. Senior Meteorologist Chris Coleman said Texas hasn’t seen an extremely cold day since Feb. 2, 2011, and its coldest month in recent history came in December 1989. Lasher warned a few very cold days could drive up demand during early morning and evening hours.
ERCOT serves about 24 million customers and 90% of Texas’ load. The ISO has added 600 MW of new capacity since the preliminary winter SARA was released Sept. 1, and an additional 800 MW are expected to be in operation by December. New natural gas, wind and solar resources are expected to provide another 1,700 MW of capacity for the spring.
