The Electric Reliability Council of Texas (ERCOT), the state grid operator and manager of the wholesale electric market, released a winter 2011/2012 assessment, the first of a new report created to provide a more complete picture of near-term risks.
“Our assessment indicates a concern if we experience a simultaneous occurrence of extreme weather and worst-case generation outages, much like February of this year,” said CEO Trip Doggett.
“Under normal weather conditions, the winter peak demand should be around 53,600 megawatts (MW). Available resources, based on normal generation outage rates, are approximately 64,000 MW,” Doggett said.
“However, under extreme weather conditions, the winter peak demand could be approximately 60,000 MW. Available resources, based on above normal generation outage rates, could dip to approximately 57,000 MW,” Doggett said. “We believe the risk is very low of these simultaneous conditions, but the purpose of this report is to highlight such risks.”
One megawatt is roughly enough electricity to power 500 average homes under normal conditions in Texas.
Last winter’s actual peak demand of 57,315 MW, recorded on Feb. 10, set an all-time winter record and surpassed the 56,334 MW peak on Feb. 2, when ERCOT asked utilities to implement controlled rotating outages following the rapid loss of 8,000 MW of generation due to low temperatures and wind chill factors.
The winter assessment is the first of a new ERCOT report – the Seasonal Assessment of Resource Adequacy– designed to enhance the grid operator’s assessment of near-term conditions. The report is intended to complement the twice-a-year capacity, demand and reserves report, which includes a 10-year outlook based on longer-term planning data.
“The seasonal assessments will be based on the most-current available data on seasonal weather, the status of power plants, and the impact of factors like economic activity and the ongoing drought,” Doggett said. “This should give us a more complete picture of resource adequacy over the next few months than the long-term planning methodology used to prepare the 10-year capacity, demand and reserves outlook.”
“We will continue to monitor the ongoing drought and how it’s affecting capacity due to its impact on cooling water resources available for generation units,” Doggett said. ERCOT estimates that the amount of generation that relies on water sources that are at historically low levels due to the ongoing drought totals 11,464 MW.
The ERCOT region includes 23 million people and represents about 85 percent of the state’s electric load. ERCOT does not include the El Paso area, the Texas Panhandle, Northeast Texas and Southeast Texas.