Federal data shows coal-fired power plant stockpiles average less than 90 days in the last decade
Energize Weekly, November 15, 2017
Federal energy regulators are considering a Trump administration proposal to give coal-fired power plants that keep 90-day fuel stockpiles a “resiliency” subsidy. But data shows that from 2010 to 2016, plants rarely kept fuel reserves that large.
Since 2016, reserves have been higher, but in August 2017, the total stockpiles slipped to 144 million tons, the lowest level since 2014, according to the federal Energy Information Administration’s (EIA) Electric Power Monthly report.
Secretary of Energy Rick Perry has submitted a proposal to the Federal Energy Regulatory Commission (FERC) to change wholesale power markets so that coal-fired and nuclear units get a subsidy for fuel stockpiles, contending these reserves add to the resiliency and security of the electric power grid.
One analysis put the cost of the proposal at about $2 billion, another said that depending on the size of the subsidy, it could cost consumers between $311 million and $10.6 billion.
The proposal drew critical responses filed with the FERC from the largest wholesale market operators, known as independent system operators (ISOs)—PJM, MISO, NYISO and ISO New England.
The FERC has until Dec. 10 to rule on the U.S. Department of Energy (DOE) proposal. FERC Chairman Neil Chatterjee has said that he is working on a short-term plan to aid at-risk coal and nuclear plants to give the commission more time to evaluate the DOE proposal.
The EIA data, however, shows that coal-fired power plants have fluctuating stockpiles and for long stretches, have had less than 90 days’ worth.
“Coal plants generally stockpile much more coal than they consume in a month,” the report said. “Coal consumed by power plants follows the seasonal pattern in overall electricity generation, meaning coal consumption is typically highest in summer and winter months and lowest in spring and fall months.”
Coal deliveries fluctuate less, but have averaged 53,000 tons a month in 2017, while the average monthly consumption rate through August was 56,000 tons, according to the EIA.
The EIA calculates “days of burn”—how long the stockpiles would last if no additional deliveries are made. The agency estimates the rate by averaging the most recent three years of data.
On average, the days of burn were below the 90-day target for most of the time between 2010 and 2016. Since then, the stockpiles have been above the target for the most part.
In the monthly update, the EIA divided plant stockpile levels into three groups—plants with more than 60 days of burn, those with 30 to 60 days and those with less than 30 days of burn.
The EIA found that as of August, 57 percent of U.S. coal-fired plants had more than 60 days of reserves, about 33 percent had between 30 and 60 days and 10 percent had fewer than 30 days of reserves.