At approximately 3:30 p.m. local time on 13 September 2026, ExxonMobil’s Joliet refinery in Will County, Illinois, suffered a site-wide power outage that activated safety systems and forced the entire plant offline. Electricity was restored at around 7 p.m., but on 14 September the refinery remained in stabilization and assessment as personnel investigated the cause and prepared individual units for restart.
The outage triggered heavy flaring, producing flames and dark smoke visible from surrounding areas. Flaring is used to dispose safely of hydrocarbons during an emergency shutdown. Available information does not establish that a major process-unit fire occurred, and ExxonMobil has not disclosed material equipment damage.
Capacity figures vary slightly by source. Reuters described Joliet as a 264,000-barrel-per-day refinery, while ExxonMobil’s 2026 facility profile lists capacity at 275,000 barrels per day. Under either measure, the plant represents approximately 6% of total refining capacity in the U.S. Midwest.
Joliet produces around 11 million gallons of gasoline and diesel each day. Its other products include LPG, asphalt, sulfur and petroleum coke. Gasoline and diesel move by pipeline into Illinois, Indiana, Iowa, Michigan, Ohio, Pennsylvania and Wisconsin, while other products are transported by truck, rail and barge.
The shutdown comes at a sensitive point for fuel markets. Ukrainian attacks have disrupted Russian refining and product exports, while conflict and shipping restrictions in the Middle East have reduced diesel availability. Average U.S. diesel prices had already moved above $6 per gallon for the first time before the Joliet outage.
Restoring power does not mean that a refinery can immediately return to full production. Utilities, circulation systems, pressure conditions, safety interlocks and individual process units must be checked and restarted in sequence. IIR Energy expects the refinery to return to normal service by the end of the week, but ExxonMobil has not issued a firm restart date.
If operations resume within several days, the market impact is likely to remain concentrated in Midwest spot prices, inventory movements and pipeline distribution. A longer outage would require refiners and wholesalers to draw additional products from the U.S. Gulf Coast or other regions.
The direct effect on chemical feedstocks appears limited at this stage, but LPG, sulfur, petroleum coke and asphalt supply could be affected. Higher diesel prices would also increase operating costs for tank trucks, container drayage and regional chemical distribution.
The incident should not yet be described as a U.S. fuel-supply crisis. What is confirmed is a complete shutdown at a refinery representing about 6% of Midwest capacity. What remains unknown is the extent of any damage, the exact restart date and the volume of production ultimately lost.
