Extreme weather, including the continued drought, won’t stop the Electric Reliability Council of Texas (ERCOT) from providing enough power to serve peak power demand in the region, officials said Sept. 3.
ERCOT’s fall Seasonal Assessment of Resource Adequacy (SARA) predicts about 74,000 MW of generation will be available to serve about 47,000 MW of anticipated peak demand during October and November.
The preliminary winter SARA projects a similar outlook for the December-February period. Currently, ERCOT expects more than 75,000 MW of generation will be available to serve anticipated peak demand during the winter months. Based on a model that anticipates weather similar to 2009, electric demand is not expected to exceed 48,000 MW this winter.
Based on the current weather outlook and average plant outages during fall peak demand hours over the past five years, ERCOT expects to have nearly 20,000 MW of capacity available for operating reserves. That range could drop to just under 4,600 MW in an extreme-load and high-outage scenario.
“The system appears to be well-prepared for fall electric needs, and that outlook continues into the coming winter months,” said ERCOT Director of System Planning Warren Lasher upon issuance of the latest SARA.
ERCOT officials said the region’s generation picture will be improved with the completion of the next phase of the Competitive Renewable Energy Zones (CREZ) transmission program. ERCOT will hold a board of directors meeting later this month in order to discuss the current 13.75% reserve margin target.
ERCOT officials said they have been effective in meeting the reserve margin target so far in 2013. ERCOT officials said they have recently received requests to idle an additional 1,900 MW of generating capacity in the region.
ERCOT continues to keep wary eye on drought
But the drought continues to be a concern, said both Lasher and ERCOT Meteorologist Chris Coleman.
“From a weather standpoint … the drought started in October 2010,” Coleman said. “You still have roughly 85-to-90% of the state in moderate or worse drought,” he added.
Unfortunately, the current forecasts don’t predict a wet fall or winter. “It still looks drier than normal for ERCOT as a whole,” Coleman said.
“We will continue to monitor the potential impact of drought conditions on power plant operations,” said Lasher. “Fortunately, we do not expect drought-related operational problems during the coming months.”
Among its other impacts, drought can squeeze cooling water supplies for fossil fuel and nuclear power plants.
ERCOT benefitted, however, from mild summer temperatures and the fall and winter forecasts currently look mild as well, ERCOT officials said.
Peak demand during the 2013 summer so far has remained below historical records. Although the season continues through September for planning purposes, ERCOT typically sees its highest demand in August. During the hottest months, air conditioning use drives up electric use, especially for residential and small commercial consumers. The peak so far this year occurred on Aug. 7, at 67,180 MW, higher than the 2012 peak of 66,548 MW but well below ERCOT’s Aug. 3, 2011, record of 68,305 MW.
Winter in the ERCOT region typically does not drive power demand to the levels the grid experiences during summer. However, rare cases of sustained extremely cold temperatures can affect generation performance and drive up electric use, especially in those areas in the ERCOT region where consumers rely primarily on electricity for heating.
ERCOT will assess any changes to the winter forecast for the final winter assessment, which is scheduled for release Nov. 1.
ERCOT manages the flow of electric power to 23 million Texas customers — representing 85% of the state’s electric load. As the independent system operator for the region, ERCOT schedules power on an electric grid that connects 40,500 miles of transmission lines and more than 550 generation units.