The Electric Reliability Council of Texas (ERCOT) expects to have enough power available to serve peak demand needs this coming fall and winter, even if extreme weather or an unusually high number of forced generation outages dip into its planning reserves.

“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 as he summed up the final fall and preliminary winter Seasonal Assessment of Resource Adequacy (SARA) reports issued today.

The fall SARA projects about 74,000 megawatts (MW) of generation will be available to serve about 47,000 MW of anticipated peak demand needs during October and November. 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.

One MW is enough to serve about 500 homes during mild seasons and about 200 homes during peak demand, typically late afternoons during the summer.

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.

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.

“We have seen predominantly mild weather this year, with some exceptions this summer," said ERCOT Meteorologist Chris Coleman. “Some hot temperatures are likely through early fall, with cooler-than-normal temperatures expected in November."

Although drought conditions continue to affect water storage levels in much of the state, generators in ERCOT do not expect the ongoing drought to affect operations during the coming fall and winter months.

“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.”

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.

Both seasonal assessments incorporate updated information on projected generation availability, weather projections, economic forecasts and other data to define a likely range of electric supply and demand scenarios.

ERCOT will assess any changes to the winter forecast for the final winter assessment, which is scheduled for release Nov. 1.