Sensor Networks for Lighting Control

This paper summarizes results from a research program investigating the development and application of sensor networks to lighting control and building energy management. Commercial, industrial and residential buildings often incorporate systems used to determine occupancy, however, current sensor technology and control algorithms limit the effectiveness of these devices in both energy management and security systems. These systems rely on single measurement points to detect occupancy, and as a result there can be significant uncertainty associated with the measurement of occupancy. Long time delay and high detector sensitivity settings compensate for this uncertainty, and as a result, more energy is wasted than if occupancy were more accurately measured. A network of inexpensive occupancy sensors provides a more accurate, reliable and robust occupancy measurement, and is potentially more economical in terms of initial investment and operating costs, than single-point detection systems. We show that it may be possible with a sensor network to reduce the operating time of occupancy-based building systems by an extra 20% (compared to current systems) and that the simple payback periods associated with wireless sensor networks applied in generic small and large commercial buildings may be less than two years.