Duke Energy Carolinas turns in poor coal burn in 2012

Duke Energy Carolinas had no luck burning down its coal stockpiles in 2012, with those stocks actually growing from 4.1 million tons at the beginning of the year, to 4.7 million tons as of the end of 2012.

That is according to a monthly fuel report for December 2012 that the utility, a unit of Duke Energy (NYSE: DUK), filed Feb. 12 with the North Carolina Utilities Commission. The report also includes full-year 2012 figures.

The utility burned only 10.7 million tons of coal in 2012, and took in 11.3 million tons, thus the growth in the coal stockpiles during the course of the year. The December 2012 and full-year inventory figures include the results of a minor adjustment the utility made to the figures after a December 2012 aerial survey of the stockpiles.

The Feb. 12 filing doesn’t show 2011 figures. But a filing by the utility in February 2012, covering the December 2011 and full-year 2011 figures, shows a coal inventory that began 2011 at 2.4 million tons, with 16.1 million tons of deliveries during the year, 14.3 million tons burned during the year, and a 4.1 million ton inventory as of the end of 2011. So, the coal inventory problem really started taking off in 2011, and continued in 2012, but at least with a lesser level of build in 2012.

Note the 14.3 million tons of coal burn in 2011, against the depressed 10.7 million tons of burn in 2012.

In December 2012, the utility took delivery of 880,826 tons of contract coal, and no spot coal, at an average delivered price of $93.98/ton. The biggest coal taker was the Belews Creek power plant, with 395,278 tons of deliveries in December at $91.99/ton. There was a small amount (nearly 3,909 tons) of coal transferred that month from the Dan River plant to Belews Creek.

Capacity factors were mediocre in 2012, even at the baseload units

The “cycling” coal units, which follow load, didn’t run much in the full year 2012. For example, at Allen Units 1-5, the full-year capacity factors ranged from 5.49% for Unit 2 to 32.06% for Unit 4. And that is the plant that ran well. For Buck Units 5-6, Dan River Units 1-3, Lee Units 1-3 and Riverbend Units 4-7, the only unit that topped 10% during 2012 as far as its capacity factor was Buck Unit 5 at 13.05%. Dan River Units 1-3, which were officially retired in April 2012, had zero capacity factors during the year.

The five baseloaded coal units did only mildly better. Note that a sixth baseload unit, the new Cliffside Unit 6, only became commercial on Dec. 30, so it isn’t in this list. The baseload coal units and their 2012 capacity factors are:

  • Cliffside Unit 5, 23.49%;
  • Marshall Unit 1, 32.31%;
  • Marshall Unit 2, 41.06%;
  • Marshall Unit 3, 56.46%; and
  • Marshall Unit 4, 67.31%.

The last page of the Feb. 12 filing shows estimated fuel savings for December 2012 related to the takeover last year by Duke Energy of Progress Energy Carolinas and the resulting combination of fuel operations of the two North Carolina subsidiaries.

Buck and Riverbend will be retired two years earlier than scheduled, Duke Energy announced Feb. 1. Both stations had been slated for retirement in April 2015 in advance of upcoming federal environmental regulations. However, the company elected to retire Buck Units 5-6 and Riverbend Units 4-7 early, on April 1, 2013. The units have been operating infrequently in recent years and in the future would have operated even less with the recent completion of new, more efficient plants, and in the face of competition from low natural gas prices.

  • Buck entered commercial operation in 1926. Its original two units were retired in 1979, and Units 3-4 were retired in May 2011. Units 5-6, 128 MW each, began operating in 1953. Three smaller natural gas combustion turbines at the site were retired in October 2012. The natural gas-fired Buck Combined Cycle Station (620 MW) began commercial operation in November 2011.
  • Riverbend began operating in 1929, and Units 1-2 were retired in 1979. Unit 3 was retired in 1976. Units 4-5, 94 MW each, began operating in 1952, and Units 6-7, 133 MW each, began operating in 1954. Four smaller natural gas combustion turbines at the site were retired in October 2012.
About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.