Environmental Thermal Energy Scavenging Powered Wireless Sensor Network for Building Monitoring

Abstract

In recent years there has been increasing interest in innovative design and construction of sustainable highperformance buildings. Among the innovative techniques proposed to increase building performance is to dynamically sense, control and manage the ambient building environment, such as temperature, humidity, air quality, artificial lighting, etc. through the installation of a distributed wireless sensor network (WSN). It has been reported that such an intelligent building monitor and control system can result in an approximately 20% savings in energy usage, a substantial step toward the realization of smart building management. In conventional WSNs, battery power is used to energize these micro-scale sensors. The small space permitted for battery integration in these miniaturized systems is a limiting factor. The small battery will be quickly depleted requiring frequent battery replacement or the WSN system will cease operation. Frequent battery replacement is impractical due to the tremendous number of sensor nodes embedded in a typical WSN system. This key design challenge in WSN based building monitoring and control must be overcome in order to significantly prolong the life of the overall system operation. In this paper, the authors investigate the construction of a novel WSN system for intelligent building environment monitoring powered through the use of micro-scale thermoelectric generators (TEG). In the TEG, the ambient thermal gradient between two surfaces of the device is converted into electrical energy. To verify the feasibility of the proposed idea, an experiment was conducted and the results demonstrated the concept of harvesting ambient thermal energy to power wireless sensors.