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Today in Energy

May 17, 2019

Coal stockpiles at U.S. coal power plants were at their lowest point in over a decade

coal stocks for electricity generation
Source: U.S. Energy Information Administration, Electric Power Monthly

U.S. coal stockpiles decreased to 98.7 million tons in February 2019, their lowest value in more than a decade. Total U.S. coal stockpiles have fallen as more coal plants have retired.

Coal plants generally stockpile much more coal than they consume in a month. Coal consumed by power plants follows the seasonal pattern in overall electricity generation, meaning coal consumption is typically highest in summer and winter months. Because coal-fired power plants are consuming more coal in the warmest summer months and coldest winter months, coal stocks at power plants are often at their lowest in August and February.

In addition to surveying coal stockpile levels, EIA also calculates how long these stockpiles would last, assuming the power plants receive no additional coal. This value, known as days of burn, considers each plant’s current stockpile level and its estimated consumption rate in the coming months. In February 2019, U.S. coal power plants had, on average, about 90 days of burn.

coal stocks' days of burn
Source: U.S. Energy Information Administration, Electricity Monthly Update

Because coal-fired power plants use different types of coal, EIA tracks this data based on coal rank. The two main types of coal used for electricity generation in the United States are bituminous coal, which is mostly produced in states such as West Virginia, Illinois, and Pennsylvania, and subbituminous coal, which is mostly produced in Wyoming.

For bituminous coal-fired power plants, most of which are located in the eastern United States, the average number of days of burn reached 91 days in February 2019. For subbituminous coal-fired power plants, largely located in the Midwest and West, the average number of days of burn was slightly lower at 89 days in February 2019.

coal stocks days of burn by region
Source: U.S. Energy Information Administration, Electricity Monthly Update

EIA expects coal stockpiles to remain relatively low throughout 2019, according to forecasts in EIA’s latest Short-Term Energy Outlook. Coal is expected to be the second-highest fuel for electricity generation in 2019, providing 996 million megawatthours, or 24% of total electricity generation, second only to natural gas at 1,505 million megawatthours (37%). To provide that electricity, the U.S. power sector is forecast to consume about 555 million short tons of coal. If realized, this level of coal consumption by the U.S. power sector would be the lowest since 1979.

coal stockpiles for electricity generation
Source: U.S. Energy Information Administration, Short-Term Energy Outlook, May 2019

Principal contributors: Chris Cassar, Owen Comstock