Coal stockpiles at U.S. power plants fell 1.6 percent this week and were 16 percent smaller than a year ago, Genscape said on Jul 27.

U.S. generators, which rely on coal to fuel about half of domestic electricity output, had 55 days worth of coal on hand as of Jul 26, two less than last week, the data provider said.

Power companies averaged 11 days less supply of coal stockpiled than the same week of 2009, Genscape said.

Power generators had 152.5 million tonnes of coal as of Jul 26, down from 155.2 million tonnes stockpiled on Jul 19 and down from 181.6 million tonnes the same week last year, Genscape said.

The 29 million-tonne drop from coal supplies in the same week last year partly reflects the economic rebound raising demand after coal production was cut due to last year's economic slump.