Energy Harvesting
“Energy harvesting” means collecting energy from an external ambient energy source, such as light, heat, movement or EM fields and storing it as electrical energy in a battery or capacitor for later use. The principle is that a continuous supply of low-level energy can be harvested to provide a short-term higher energy output. The stored energy is typically used to supply power to low-power wireless electronic devices, such as microprocessors, sensors, or network communications.
Fig. 1: the electromagnetic spectrum of UV and visible light
![](http://g.recomcdn.com/media/CMSTextComponent-textImages/value/.fiOipVsX/CMSTextComponent-textImages-564.jpg)
Fig. 1: the electromagnetic spectrum of UV and visible light