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Energy is everywhere in the environment surrounding us — available in the form of thermal energy, light (solar) energy, wind energy, and mechanical energy. However, the energy from these sources is often found in such minute quantities that it cannot supply adequate power for any viable purpose. In fact, until recently, it has not been possible to capture such energy sufficiently to perform any useful work.
This scenario is about to change.
Energy Harvesting is the process of capturing minute amounts of energy from one or more of these naturally-occurring energy sources, accumulating them and storing them for later use. Energy-harvesting devices efficiently and effectively capture, accumulate, store, condition and manage this energy and supply it in a form that can be used to perform a helpful task. Similarly, an Energy Harvesting Module is an electronic device that can perform all these functions to power a variety of sensor and control circuitry for intermittent duty applications.
Why Energy Harvesting?
Advanced technical developments have increased the efficiency of devices in capturing trace amounts of energy from the environment and transforming them into electrical energy. In addition, advancements in microprocessor technology have increased power efficiency, effectively reducing power consumption requirements. In combination, these developments have sparked interest in the engineering community to develop more and more applications that utilize energy harvesting for power.
Energy harvesting from a natural source where a remote application is deployed, and where such natural energy source is essentially inexhaustible, is an increasingly attractive alternative to inconvenient wall plugs and costly batteries. This essentially free energy source, when designed and installed properly, is available maintenance-free and is now available throughout the lifetime of the application. Such systems can be more reliable than wall plugs or batteries.
In addition, energy harvesting can be used as an alternative energy source to supplement a primary power source and to enhance the reliability of the overall system and prevent power interruptions.
Energy Harvesting Applications
Many real life applications using energy harvesting system power are now practical. Wireless sensor network systems such as ZigBee systems often benefit from energy harvesting power sources. For example, when a wireless node is deployed at a remote site where a wall plug or a battery is either unreliable or unavailable, energy harvesting can augment or supply power. In another example, a remote control node running on energy harvesting can be implemented as a self-powered electronic system. And in yet other situations, multiple energy sources can be used to enhance the overall efficiency and reliability of any system.
Common Sources of Energy Harvesting
- Mechanical Energy – from sources such as vibration, mechanical stress and strain
- Thermal Energy – waste energy from furnaces, heaters, and friction sources
- Light Energy – captured from sunlight or room light via photo sensors, photo diodes, or solar panels
- Electromagnetic Energy – from inductors, coils and transformers
- Natural Energy – from the environment such as wind, water flow, ocean currents, and solar
- Human Body – a combination of mechanical and thermal energy naturally generated from bio-organisms or through actions such as walking and sitting
- Other Energy – from chemical and biological sources
It is important to note, that all these energy sources are virtually unlimited and essentially free, if they can be captured at or near the system location.
Components of an Energy Harvesting System
An energy harvesting system generally requires an energy source such as vibration, heat, light or air flow and three other key electronic components, including:
- An Energy conversion device such as a piezoelectric element that can translate the energy into electrical form
- An energy harvesting module that captures, stores and manages power for the device
- An End application such as a ZigBee-enable wireless sensor network or control and monitoring devices.
Note: If your company produces an energy harvesting product and has a datasheet and pricing information please submit such information to be added to this website by contacting ehadmin@energyharvesting.net
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