This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter, fixed carbon, and ash content are determined for each sample and comparisons are made. Proximate analysis is performed on a coal sample from a local electric utility. From the weight percent sulfur found in the coal (determined by a separate procedure--the Eschka method) and the ash content, students calculate the quantity of sulfur dioxide emissions and ash produced annually by a large coal-fired electric power plant. (Contains 3 figures, 1 table and 5 notes.)