Because nearly 70 percent of the overall cost of electric power consists of the cost of fuel, utilities must monitor the fuel flow rate to each generating unit to develop an accurate calculation of costs. But most units are not equipped to provide this measure, so the rate instead is calculated indirectly by performing an energy analysis of the entire unit. In all of the existing methods, coal analysis is needed to start the calculations, but unfortunately coal analysis is rarely available on-line. These limits make for problems in calculating costs in real-time.
A new technique developed at the Center for Electric Power at Tennessee Technological University offers utilities a different approach to calculating fuel flow rate on an on-demand basis, using a method that hinges on flue gas data, which is readily available due to the 1990 Clean Air Act.
Software based on this method received approval on a trial basis by the U.S. Environmental Protection Agency and was installed first at Alabama Power, which found it successful, and is now in use on a unit operated by Eastman Chemical Company in Kingsport.
The effort was developed with funding by Alabama Power and led by researcher Sastry Munukutla, a mechanical engineering professor with the Center for Electric Power. According to Munukutla, trial runs of the technique have found it achieves its aim: being as effective as current, indirect methods of cost analysis while yielding calculations in real-time in a manner that supports hourly reports of cost.
The Center for Electric Power is one of three state-funded Accomplished Centers of Excellence in operation in the College of Engineering at Tennessee Tech.