US utility coal stockpiles dip slightly in September, but days of burn remain elevated

Houston — US utility sector coal stockpiles stood at 129.1 million st at the end of September, down 0.3% from the previous month, but up 16.4% from the year-ago month, according to Energy Information Administration data issued Nov. 24.

The monthly total was also down 3.6% from the five-year average for the month.

Bituminous coal stockpiles stood at 50.3 million st at the end of September, down 1% from August, up 2.4% from the year-ago month, and down 12% from the five-year average for the month.

Subbituminous coal stockpiles stood at 74.6 million st at the end of September, up 0.3% from August, up 26.1% from the year-ago month, and up 1.5% from the five-year average for the month.

On a days-of-burn basis, bituminous coal stockpiles stood at 116 days at the end of September, down 7.2% from the prior month, but up 16% from the year-ago month and up 27.5% from the five-year average for the month.

Subbituminous coal stockpiles on a days of burn basis stood at 105 days at the end of September, up 1% from August, up 32.9% from the year-ago month, and up 29.3% from the five-year average for the month.

The recent EIA stockpile data conforms with recent trends, which show aggregate stockpile data relatively in line with five-year averages, but days of burn data being exceptionally higher.

Coal generation has fallen dramatically in recent years due to cheap natural gas, which has pushed up coal stockpiles, though the increase is masked by the number of coal plant retirements which make the stockpiles look more in line with the five-year averages.

The days-of-burn data instead show the size of the discrepancy between actual supply and demand, as 60 days of burn is generally considered the target for plant managers.

The last time bituminous coal stockpiles on a days of burn basis were at 60 days or below as July 2014, and December 2014 for subbituminous days of burn.