Philadelphia Energy, operator of the largest U.S. east coast oil refinery, has filed for Chapter 11 bankruptcy protection. That’s been in part due to higher renewable energy costs. The refiner had bucked the national trend in becoming more reliant on overseas oil, with imports in 2017 being 4.1x those of 2015. Yet, activity clearly slowed recently with imports in the fourth quarter being 34% lower than in the third quarter. The leading suppliers of overseas oil to Philadelphia were Shell Trading (14% of the total), Sonatrach (12%) and Total (6%).