For TECO Coal buried treasure doesn't have to be bright and shiny, sometimes it's coal black. The company, a subsidiary of TECO Energy, owns 13 operating subsidiaries that mine and produce about 9 million tons of volatile metallurgical, ultra low ash, and low sulfur coal annually. Additionally, the company makes synthetic fuel and processes coal. The mines and facilities are in Kentucky, Tennessee, and Virginia. TECO Coal operates underground and surface mines (about 30 and 15, respectively) from four mining complexes. None of the coal it produces is sold to TECO's electric unit; the company's primary customers are the steel industry and unaffiliated electric utilities.