US coal stockpiles fall 0.45 pct - Genscape

HOUSTON, Nov 10 (Reuters) - Coal stockpiles at U.S. power plants this week shrank 0.45 percent from last week on reduced deliveries, but stockpiles were still 13.2 percent greater than the same week of 2008, Genscape said Tuesday.

Generators had 183.7 million tons of coal on hand as of Tuesday, compared with 184.5 million tons last Tuesday and 162.3 million tons the same week last year, the power industry data provider said.

As of Tuesday, U.S. generators - which rely on coal for about half of U.S. electricity generation - had an average of 70 days' supply of coal assuming typical burn rates, Genscape said. That is the same as last week's estimated coal capacity.

As of Tuesday, power plants averaged eight more days' supply on hand than the same week last year. That is two days less than last week's cushion over 2008 stockpiles, data showed.

"The driving force behind the erosion in the mountain of reserves held by power plants is a reduction in supply. Demand is recovering slowly, but it is not nearly robust enough to dispense with the coal overhang," Genscape said.

Coal inventories typically grow in spring and fall when demand for heating and cooling drops, but the seasonal buildup this year has been much slower than last year due to months of oversupply and weak power demand in a struggling economy, Genscape said.

During summer and winter, stockpiles typically shrink because hot or cold weather tends to boost power consumption for air-conditioning or heating. This year, the seasonal drawdown was weak, leaving coal stockpiles bulging at the end of the summer.

Genscape has said comparisons with last year became less meaningful after September because the economy weakened sharply in the autumn of 2008, reducing coal demand.

Mathematical rounding sometimes affects the results, overstating some changes and understating others, Genscape has said. (Reporting by Bruce Nichols; Editing by Lisa Shumaker)