C6.3 - Thermo Harvesting – More and Enduring Power for Wireless Systems
- Event
- SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg - Band
- Proceedings SENSOR 2009, Volume II
- Chapter
- C6 - Energy Harvesting
- Author(s)
- B. Habbe - Micropelt GmbH, Freiburg, Germany
- Pages
- 213 - 218
- DOI
- 10.5162/sensor09/v2/c6.3
- ISBN
- 978-3-9810993-5-5
- Price
- free
Abstract
Wireless sensor systems gain increasing market shares in a growing number of markets, from smart metering into Industrial condition and process monitoring. The driving force of almost all of these nodes is some sort of a battery. Hence, battery capacity is predominantly determining performance and features of such systems. Both of these criteria as well as the system’s duty cycle have to follow the limits given by capacity and price of the energy storage. As battery changes – except for private households - cause additional maintenance cost and recycling issues, many potential users avoid wireless devices altogether.
On the other hand the power requirements of novel radio and sensor systems have decreased substantially, making it possible to drive e.g. smart energy meters for remote readout beyond their calibration period of 10 years – with just a button cell. Sure, the trade-off is in a reduced feature set and the least possible duty cycle to ensure both regulatory compliance and basic functionality requirements of the energy provider. Many useful and advanced features such as daily readout, peak usage billing and usage control are renounced due to a lack of installed energy.
However, with closer proximity of applications to condition or process monitoring in industrial environments both minimum required feature-set and duty cycle expand considerably. Reliability is indispensable and decreasing the scan rate may compromise the application. Wireless transmission must be as reliable as its wired equivalent, despite multiple sources of electromagnetic interference along the transmission path. Wireless sensors have the capability of removing guesswork and indirect risk management from the agendas of both process operators and maintenance managers. Statistical and simulation based maintenance and operation may be upgraded to real control, enhancing the utilization of assets while reducing operational risks. However, a major factor standing in the way of wireless sensors remains the maintenance cost and effort associated with batteries.
To overcome both the constraints of limited power capacity and extensive maintenance cost of batteries a growing number of vendors offer a variety of energy harvesting technologies and devices. The concept they all have in common is converting excess or waste energies such as vibration, motion, magnetic and electric fields, and heat into a useful form of electrical energy. These offerings converge well with the decreasing power requirements of wireless systems and microelectronics in general.