Wireless networked lighting systems for optimizing energy savings and user satisfaction

Energy savings and user satisfaction are two major design considerations for modern lighting systems. While some new commercial lighting systems for shared-space office buildings have been able to achieve significant savings via various lighting control strategies, the occupants’ diverse lighting preferences and visual comfort have been generally overlooked or even compromised. Moreover, retrofitting legacy buildings with modern lighting systems is still economically unattractive due to the high cost of global rewiring. Leveraging the versatility of wireless sensor and actuator network technologies, this paper describes a wireless networked lighting system that fulfills both design criteria for modern lighting systems - energy efficiency and user satisfaction. The intelligent lighting optimization algorithm formulates lighting control as a linear programming problem to minimize energy usage and meet occupants’ lighting preferences at the same time. The hardware of the lighting system is designed with minimizing retrofitting efforts and costs in mind, and an implementation of the developed system in a multiperson office shows substantial energy savings while meeting users’ lighting preferences.