This Public Final Design Report describes the 70 MW(e) Tidd PFBC Demonstration Plant under construction in Brilliant, Ohio. This project is receiving cost-sharing from the US Department of Energy (DOE), and is being administered by the Morgantown Energy Technology Center in accordance with DOE Cooperative Agreement No. DE-FC21-87 MC24132.000. The project is also receiving costsharing from the State of Ohio. This award is being administered by the Ohio Coal Development Office. The Tidd PFBC Demonstration Project is the first utility-scale demonstration project in the US. Its objective is to demonstrate that the Pressurized Fluidized Bed Combustion (PFBC) combined-cycle technology is an economic, reliable, and environmentally superior alternative to conventional technology in using high-sulfur coal to generate electricity. Detailed design of the plant began in May 1987, leading to the start of construction in April 1988. First coal fire occurred in November 1990, and the three-year test program began in February 1991.