In this paper, a fractional-order (FO) adaptive minimum energy cognitive lighting control strategy is developed to minimize the energy usage in a hybrid lighting system. A hardware-in-the-loop prototype of a cognitive hybrid lighting control plant is designed and built. The FO lighting control strategy is the combination between an FO extremum seeking controller (ESC) and a proportional integral derivative (PID) controller. The FO ESC guarantees the minimized energy usage, while the PID controller is applied to achieve a comfortable light level. The FO ESC demonstrates an improved convergence speed and accuracy. The experimental results are presented to demonstrate the practicality and effectiveness of the proposed FO minimum energy cognitive lighting control scheme. (C) 2014 Elsevier B.V. All rights reserved.