October 23, 2026 - U.S. electric power sector coal stockpiles declined 5.9% in August 2026, reaching approximately 102 million tons as power plants used stored fuel to meet summer electricity demand, according to the U.S. Energy Information Administration.

The figures, released October 23 in EIA’s Electricity Monthly Update, reflect inventories during August rather than current October conditions. EIA described the monthly decline as a normal summer pattern, when increased plant operations draw down coal supplies. Estimated fuel coverage remained comparatively steady, with average days of burn declining slightly for bituminous coal plants and holding unchanged for subbituminous plants.

The inventory drawdown came during a month of higher electricity production. Total U.S. net generation increased 6.8% from August 2025, while coal consumption for power generation rose 1.1%, according to EIA’s accompanying monthly release. Warmer weather across much of the country contributed to increased generation, with all seven electricity regions recording year-over-year gains in total output.

Stored fuel and operating requirements

Coal inventories provide power plants with fuel already on hand for future generation. Their significance depends on both the amount stored and the rate at which plants consume it.

EIA measures that relationship through its “days of burn” estimate. The calculation compares end-of-month stocks with average daily consumption based on the previous three years. It estimates how long those inventories would last without additional deliveries under the historical consumption assumptions used in the calculation.

For bituminous coal units, located largely in the eastern United States, average days of burn decreased from 127 in July to 125 in August. For subbituminous units, located largely in the western United States, the estimate remained at 119 days.

Both measures were slightly higher than a year earlier. In August 2025, bituminous plants averaged 123 days of burn, while subbituminous plants averaged 117 days. The comparison shows that August’s monthly inventory decline occurred alongside estimated fuel coverage that remained above the corresponding year-earlier levels.

These estimates describe fuel availability under a defined calculation. Actual coverage will change with electricity demand, plant operations and subsequent coal deliveries.

Regional inventories show different patterns

EIA’s regional figures reveal substantial differences across the country. These figures cover the sample of plants used to calculate days of burn and therefore do not add up to the broader 102-million-ton national stockpile total.

Within that sample, bituminous inventories totaled approximately 29.26 million tons in August, down 3.0% from July and 1.4% from August 2025. Subbituminous inventories totaled approximately 59.81 million tons, down 7.1% for the month but up 2.8% from a year earlier.

The Midwest recorded a particularly strong year-over-year increase in subbituminous stocks. Inventories reached 28.56 million tons, an 18.1% increase from August 2025, despite declining 5.3% from July. Estimated days of burn increased to 112, compared with 108 in July and 102 a year earlier.

Western subbituminous inventories moved lower on both comparisons. Stocks totaled 26.41 million tons, down 8.6% from July and 7.5% from August 2025. Estimated coverage declined to 141 days from 148 in July and 147 a year earlier.

In the South, sampled bituminous stocks fell 8.1% from July to 16.42 million tons, with estimated coverage decreasing from 126 to 121 days. Southern subbituminous stocks declined 9.2% to 4.84 million tons and were 10.8% below a year earlier.

Even so, estimated days of burn for Southern subbituminous plants increased from 74 in July to 79 in August. The figures illustrate why stockpile tonnage and estimated fuel coverage must be evaluated together: the days-of-burn measure also incorporates historical consumption patterns.

Coal generation gains varied across power markets

Coal’s contribution to the increase in electricity production differed by region.

Coal-fired generation rose from August 2025 levels in the Southeast, Florida, Texas and Mid-Atlantic, while declining in the West and Central regions. Natural gas generation increased in every region except Texas.

Coal also gained share relative to natural gas in the fossil-fuel consumption mix in Texas, the Southeast and Florida, measured by energy content. Natural gas gained share at coal’s expense in the West, Central and Mid-Atlantic regions.

Those differences help explain why a national inventory figure cannot fully describe the conditions facing individual plants or coal suppliers. Fuel use and stockpile requirements vary with regional generation patterns and the competition among available resources.

What the inventory figures mean for coal markets

For coal producers and transportation providers, the August drawdown documents the use of previously accumulated supplies during the summer generating season. It does not, by itself, establish how much additional coal utilities will purchase or when those purchases will occur.

The days-of-burn figures provide additional context. National averages of 125 days for bituminous plants and 119 days for subbituminous plants show the relationship between stored fuel and historical consumption, while regional results identify differences hidden within those averages.

EIA notes that stockpile levels can become especially important to reliability when fuel transportation routes experience significant disruptions. Evaluating that exposure requires attention to individual facilities and delivery arrangements as well as national inventory totals.

EIA’s next Electricity Monthly Update is scheduled for November 24, 2026. That release will provide the next monthly view of inventories following August’s seasonal drawdown.