Silicon Laboratories has designed an energy harvesting system built using its Si10xx wireless microcontroller (MCU) family. This single-chip MCU from Silicon Labs is specifically designed to be energy-efficient. It can be used to carry out wireless interface functions and control at very low energy levels.
The new energy harvesting device equips developers to use these wireless sensor networks, consuming very minimal power in monitoring systems for infrastructure and agriculture, asset tracking equipment, medical monitoring equipment, industrial control systems, security devices, and home and building automation.
The energy harvesting system consists of three parts. The system features a wireless sensor node powered by solar energy to measure the charge level, light level and temperature. A Si10xx wireless MCU regulates the sensor system and sends out data wirelessly. It also uses a battery, made using thin-film, to amass the harvested energy.
The reference design has a wireless USB adapter incorporated in it to display sensor information. The system also features a GUI to display information of up to four sensor nodes. A wireless USB adapter links the wireless sensor node and the PC to display sensor data. The capacity of the thin film battery utilized in the energy harvesting reference design is 0.7 mAh. When exposed to direct sunlight, the battery needs to be recharged every two hours but while in the sleep mode, the charge retention lasts for around 7000 hours.
Source: http://www.silabs.com