Polar vortex spurs peak demand for many utilities

The bone chilling weather across much of the country in recent days has resulted in a number of records or near-records for peak winter demand.

Here are some of the peak numbers from the polar vortex:

An American Electric Power (NYSE:AEP) subsidiary, Appalachian Power (APCO), said Jan. 8 that it had set an unofficial all-time peak demand of 8,410 MW at 8 a.m. Tuesday, Jan. 7. Arctic cold weather across the company’s entire service area helped push electricity consumption past the previous record of 8,308 MW set on Jan. 16, 2009.

The new company peak will be confirmed next month when additional metering information is available to verify the customer consumption, APCO said.

Dominion (NYSE:D) said Jan. 8 that its Virginia operations met a record winter peak demand.

Dominion supplied 19,730 MW of electricity between 7 a.m. and 8 a.m. Tuesday Jan. 7.  That is an increase of about 1,650 MW over the previous winter peak demand record of 18,079 MW, which was set between the same hours on Feb. 6, 2007.  The all-time peak demand record is a summertime mark of 20,061 MW set on July 22, 2011. 

In addition, Dominion also established an all-time record for energy usage over a 24-hour period. Total energy usage for Tuesday was 419,791 MWh. The old record was 392,347 MWh set on July 23, 2011.

Duke Energy (NYSE:DUK) said Jan. 7 that two of its subsidiaries, Duke Energy Progress and Duke Energy Carolinas experienced record electricity demand.

The Electric Reliability Council of Texas (ERCOT) said Jan. 7 that subzero temperatures resulted in a new winter record, with electric use peaking at 57,277 MW in the hour ending at 8 a.m.

ERCOT’s previous winter demand record of 57,265 MW was set on Feb. 10, 2011. The all-time record overall was set on Aug. 3, 2011, when demand peaked at 68,305 MW.

Nebraska Public Power District (NPPD) set a likely new all time-winter peak for generating electricity on Jan. 6. Between the hour of 7 and 8 a.m., as people readied a Monday morning back to school or work, NPPD generated an estimated 2,256 MW of electricity to meet customers’ demand. The utility’s previous all-time winter peak was 2,219 MW set in December of 2009.

“NPPD was able to meet this highest level of demand, in part, due to our steady and stable supply of power generated by our nuclear and coal-fired facilities,” said President and CEO Pat Pope. “But the wind also worked in our favor yesterday, contributing more than 216 megawatts for NPPD during the time of peak demand.”

The Tennessee Valley Authority (TVA) said Jan. 8 that it had set single-day record for electricity use on the previous day. TVA’s seven-state region used 703 gigawatt-hours (GWh) of electricity on Tuesday Jan. 7, the most ever for a 24-hour, one-day period. TVA’s previous record was 701 GWh on Jan. 8, 2010.

The Valley’s average temperature Tuesday never got above 21 degrees, and the average was just 4 degrees that morning when TVA’s power system experienced its second highest winter peak power demand in the public utility’s history.

TVA also relied on its diversified portfolio of electric generating sources. To meet the 32,490-MW peak load on Tuesday, TVA received 28% of its power from coal-fired plants, 21% from nuclear plants, 14% from combined cycle natural gas plants, 11% from hydroelectric dams, 10% from conventional gas turbines, 2% from wind farms and 13% from power market purchases.

About Wayne Barber 4201 Articles
Wayne Barber, Chief Analyst for the GenerationHub, has been covering power generation, energy and natural resources issues at national publications for more than 20 years. Prior to joining PennWell he was editor of Generation Markets Week at SNL Financial for nine years. He has also worked as a business journalist at both McGraw-Hill and Financial Times Energy. Wayne also worked as a newspaper reporter for several years. During his career has visited nuclear reactors and coal mines as well as coal and natural gas power plants. Wayne can be reached at wayneb@pennwell.com.