An investigation of the accuracy and the characteristics of the peak-shaving method applied to production cost calculations

An extensive study of the peak-shaving method (PSM) is presented. A wide range of load factors and hydro ratio systems have been tested and compared with the results of the rigorous coordination-equation method (CEM). It has been found that the PSM has always scheduled more water in the high-load period than the CEM. The PSM, therefore, is more likely to swing the hydro plants and may thus avoid frequent on/off operation of thermal units. For the same amount of water to be released, the PSM produces up to 0.5% less electrical energy and results in up to 0.3% high production cost, compared to CEM. These differences are so small that they are negligible in practical application.>