Many control solutions are currently available for controlling energy system operations. Newly developed solutions for established systems are assumed to demonstrate improvement over previous solutions especially in cost savings. We have found this to be true in the area of HVAC (heating, ventilation, and air conditioning) systems. This paper provides a useful methodology for quantitative comparison of control solutions with respect to operational costs, achieved quality of control, and external conditions that could also play important roles. (C) 2012 Elsevier Ltd. All rights reserved.