Cheap natural gas has slashed coal traffic across the U.S. rail network and in turn hit demand for diesel, demonstrating the interlocking relationship between the country's energy and transport systems.
Most categories of bulk freight were down compared with 2015 but by far the largest drop occurred in coal, the single-largest commodity hauled on the network.
The number of railcars loaded with coal in the first 12 weeks was down by 32 percent compared with 2015 ("AAR reports weekly rail traffic for the week ending March 26").
Coal loadings are down because power plants have switched to burning inexpensive natural gas, which has left them with record stockpiles of unburned coal and cutting deliveries.
That in turn is reducing the number of railcars moving across the tracks and the railroad companies' purchases of diesel, leaving diesel stocks at a seasonal record.
So in a roundabout way, the shale (gas) revolution has battered the U.S. coal industry and in turn hurt the railroads, and in the process is worsening the imbalances in the diesel market.
Gas Displaced Coal
U.S. power plants burned 740 million short tons of coal in 2015, down 13 percent from 2014, and the smallest quantity since 1987, according to the Energy Information Administration (http://tmsnrt.rs/1UHzJ8a).
Coal stocks at power plants surged to 197 million tons at the end of 2015, up 30 percent from the end of 2014 ("Electric power monthly", EIA, March 2016).
Some analysts attribute the slump in coal-fired power generation to clean energy policies or a mild winter caused by the El Nino weather phenomenon, but the main reason is fierce competition from cheap gas.
Total generation at utility-scale facilities was unchanged last year from 2014, according to the EIA, which suggests weather-related demand was not the main cause of the coal slump.
Coal-fired generation fell by 226 terawatt-hours (TWh) in 2015. Renewable generation rose by 11 TWh. But gas-fired generation increased by around 208 TWh (http://tmsnrt.rs/1UHzOc5).
The volume of natural gas burned in U.S. power plants surged by almost 18 percent to a record 10 trillion cubic feet.
The average cost of natural gas delivered to electricity generators declined by 40 percent over 2015 compared with a 14 percent fall in the cost of coal.
Coal remained cheaper as a fuel than gas but the change in relative prices encouraged a shift in the generation mix towards gas.
In the short term, abundant gas thanks to the shale revolution, rather than climate policies, has reduced coal combustion and curbed carbon emissions.
Coal Hits Railroads
Coal is the single largest commodity moved by transportation networks in the United States, with the possible exception of crude petroleum, for which measurement problems prevent an accurate comparison.
Roughly two-thirds of the coal moves from mine to power plant in whole or part by rail ("Railroad deliveries continue to provide the majority of coal shipments to the power sector", EIA, June 2014).
In turn, coal is the biggest commodity hauled across the railroad network and vital to the commercial success of the railroad companies ("Railroads and coal", AAR, July 2015).
Coal accounted for 38 percent of all tonnage carried on the rails and 19 percent of all railroad revenues in 2014 ("Annual and quarterly commodity survey", Surface Transportation Board, 2015).
So the slump in coal combustion has had an immediate and significant impact on volumes across the rail network and the revenues of the major railroads.
Burlington Northern Santa Fe railroad, the largest coal carrier, has furloughed about 10 percent of its workforce owing to lower demand for coal and oil shipments ("BNSF furloughs have hit 4,600 employees nationwide", Star-Telegram, March 31).
Rail Slump Hits Diesel
The railroads are in turn one of the biggest consumers of diesel fuel in the United States, so the rail slump has contributed to the drop in distillate demand.
Railroads accounted for 6 percent of all diesel sold in the United States in 2014 ("Sales of distillate fuel oil by end use", EIA, 2015).
The Burlington Northern-Santa Fe railroad, now owned by Warren Buffett's Berkshire Hathaway, is the second-largest buyer of diesel in the United States after the U.S. Navy.
Once the other major railroads are included, the rail sector is the largest consumer of diesel fuel after road transport (63 percent) and home heating (6 percent).
Railroads consume around 240,000 barrels per day of distillate fuel, which is not large enough to have a major impact on diesel demand on its own but in combination with other factors has had a material effect.
The slump in oil drilling coupled with efforts by manufacturers, distributors and retailers to combat overstocking has led to a broad-based drop in freight movements including on the roads.
Oil drillers were also major consumers of diesel fuel to run their diesel-electric motors for drilling and ancillary oilfield power.
U.S. distillate consumption dropped by 60,000 barrels per day in 2015 (1.5 percent) after rising by more than 200,000 bpd (5.5 percent) in 2014 and 85,000 bpd in 2013 (2.3 percent).
Distillate consumption declined last year even as the economy grew and gasoline use increased by 240,000 bpd (2.7 percent), according to the EIA ("U.S. refiners press on despite unbalanced fuel demand", Reuters, March 31).
(By John Kemp)