Sensor-related Energy Saving Technologies

1. Sensor-related Energy Saving Technologies Ping-He Chen Professor National TaiwanUniversity Da-Sheng Lee Associate Professor National Taipei University of Science and Technology

2. Outline • Introduction • Sensor networks for energy saving • Power consumption of sensor nodes • Power Supply for Ubiquitous Sensor • Energy harvesting chip • Sensor network for energy saving application in a convenience store • Energy saving system with RFID and smart lighting

3. Introduction • Internet of Things • Google earth- vedio • 中華電信 – HINET of smell, hearing, and feeling • sensors, energy provider, communication, carrier, processor, and service.

4. Government Policy In 2008, 1% Reduction in CO2 emission in Taiwan, equivalent to 3.9 B KW-h, is achieved only by applying a policy called “Discount in electricity bill by encouraging energy saving of household”. The policy encourages the resident of household to reduce electricity usage by using a simply formula, 5% discount in electricity bill if 95%<ytoy monthly electricity usage ratio (MEUR) <100% 10% discount in electricity bill if 90%<ytoy MEUR < 95% 20% discount in electricity bill if ytoy monthly electricity usage ratio<90%

5. User-Friendly Technologies • System can be self-adjusted for being operated at its designed efficiency. • Electronic devices can be designed to use the least amount of stand-by power. • Environment controlled facilities, temperature and humidity, and lighting consume most power in business buildings and residential houses. Therefore, heating, ventilation, air-conditioning, and lighting should be automatically adjusted to a condition that is reasonably comfortable to the resident.

6. Sensor Networks for Energy Saving in a Living Space • It requires a sensor network to keep resident in a living space comfort but to consume the least energy. • Heating, ventilation, air conditioning, and lighting can be controlled by distributed controlunits. • We require a sensor network that has a microchip for harvesting energy from environment, and a microprocessor for analyzing the data, and a RF module for having remote communication capability.

7. Sensor Networks for Energy Saving in a Living Space Traditional Building Automation System • Heating, ventilation, air-conditioning, and lighting of a living space are controlled by a centralized unit without information in each distributed zone, for instance, an office building.

8. Smart Building Automation System with a sensor network • Distributed sensors and distributed control units • Flexible

9. Requirement of Distributed Sensor Nodes Easy Installation Inexpensive Wireless No maintenance of battery

10. Power Supply of Sensor Node Recent achievements in wireless communications have enabled easy installation of sensor networks. Although wireless communication of sensor node can be achievement by the development of RF technologies, the sensor node power supply, through either power lines or battery power, still presents obstacles in the development of sensor networks. To allow the deployment of sensor become simple and durable, the power supply to the sensor node should be both wireless and no battery.

11. Sensor node power consumption (conti.) To date, most sensor nodes are active and use alkaline batteries as sources of energy. These batteries have fixed electricity storage, which limits the sensor node’s life time, and thus, they have to be replaced. Often, the cost of physically deploying resources to replace worn out battery outweighs the cost of the node itself. To make matters worse, the used battery causes serious environmental pollution.

12. Power Supply for Ubiquitous Sensing Ambient energy harvesting is a possible solution in the development of wireless sensor networks. Scavenging energy from renewable sources near the sensor node could be the best method for providing power to the sensor. Reducing the power consumption of the sensor node becomes a key issue!! Sensor node No battery!!

13. Communication of Sensor node powered by EM Coupling RFID communications rely on electromagnetic coupling Features of passive UHF RFID system: Coupling communication & remote energy transfer to tags Backscatter coupling can transmit energy to tags as far as 5 meters away. The special communication scheme was expected to apply for sensor networks to eliminate the battery required by node.

14. Power Consumption of Different Communication Protocols

15. ZigBeev.s. RFID Semi-passive RFID using ISO 18000-6A,B,C for long range detection of the tags. Suitable for data gathering in the residential area. ISO 802.15.4 enabled a low data transfer rate, low power and low cost sensor networks. The advantage of ZigBee chip is the high efficient routing for large area deployment.

16. Commercial productsas known as class 3tags were availableon market for integrating sensor apps. Such kinds of product still need batteries to supply power for sensor, micro processor and related circuits. How to build a batteryless power solution for sensor nodes is a key challenge.

17. RFID Sensor Node Charged with Energy Harvesting Chip • The environmental energy sources supply power in irregular, random, and burst charging. • The RFID tag enabled by harvested energy is required to capture and transfer intermittent low energy bursts to become stable power supply for normal operation.