Lot’s of people have an interest in harvesting RF energy as a “free” source of power. It’s important though to understand the applications that have a good fit and those that don’t.
At the 2010 CES, an RCA-branded device called the Airnergy WiFi Energy Harvester was demonstrated. The device has an RF energy harvester and an internal battery. It was claimed that the device recharged most of a BlackBerry battery in 90 minutes. We can only conclude that was from the internal battery and not from a WiFi router (a typical WiFi router puts out only 100mW). We’ve posted below the CES video and an entertaining analysis of this device by David Jones of the Electronics Engineering Video Blog.
Darnell Group has determined that the “crossover” from the “Introduction” phase to the “Growth” phase for energy harvesting and related micro battery products will take place in the 2009/10 timeframe. Their brief news report can be read here.
Sensors Magazine recently published the article “RF Energy Harvesting Enables Wireless Sensor Networks” by Harry Ostaffe of Powercast. The article is a brief introduction to RF energy harvesting: what it is, what it does, and how it enables wireless sensor networking applications.
Powercast will be demonstrating RF energy harvesting at the IDTechEx Energy Harvesting & Storage Conference in Denver (USA) on Nov 3-4, 2009. On display will be Powercast’s RF energy harvesting technology integrated with wireless sensors from Texas Instruments, Jennic, and EnOcean.
All of the demonstration modules are battery-free and are powered by RF energy that is converted to DC by Powercast’s P2100 Powerharvester module and stored in a supercapacitor. Harry Ostaffe of Powercast will also be giving a presentation on Practical Applications of RF Energy Harvesting.
Product Design & Development (PDD) magazine profiled energy harvesting in “The Brainstorm” section of their August 2009 issue. The questions asked of the contributors were:
“What is the future of energy harvesting? What markets will energy harvesting have the greatest impact upon?”
Jennic recently announced collaborations with multiple energy harvesting companies for vibration, solar, thermal, and RF energy harvesting to power wireless sensor networks based on the IEEE802.15.4 standard such as ZigBee PRO and 6LoWPAN. The companies involved included Micropelt, CYMBET, AdaptivEnergy, and Powercast.
Jennic’s wireless microcontrollers offer exceptionally low-current operation, and with advanced software based monitoring and control of the energy source, they are able to achieve the extreme efficiency demanded by systems powered by sustainable energy sources.
At Powercast, we used a 915 MHz radio transmitter and the P2100 Powerharvester(TM) module to power wirelessly, without batteries, the new JN5148 module which sent ID, voltage, and temperature readings back through the JN5139-based access point to a PC application.
Jimi Simpson, Jennic Product Marketing, explained, “Harvesting energy from sustainable sources presents designers with the ultimate power challenge: the energy supplied is not necessarily continuous and is available at relatively low levels. This means that every element of the design, from the sensor to the microcontroller, must be considered and managed to achieve the highest levels of power efficiency.”
A new energy harvesting group has been created on LinkedIn - Energy Harvesting and MicroPower.
This group is for professionals and researchers focused on products, applications, and solutions based on Energy Harvesting and MicroPower systems. Typical applications will include wireless sensors for environmental controls, building automation, condition monitoring, and energy management. Sources for Energy Harvesting and MicroPower include solar, thermal, vibration, RF, and motion.
Product Design & Develpoment is profiling the Gold award winners at the 2009 Sensors Expo, including an article on the Powercast P2100 Powerharvester(TM).
“While vibration energy harvesting may be most common for industrial applications, a different approach was being shown by Pittsburgh-based Powercast Corp. (www.powercastco.com). At its Sensors Expo show booth, the company was demonstrating its Powercaster transmitter, which was beaming a radio frequency (RF) signal toward the company’s Powerharvester receivers mounted in other nearby booths. The receivers were harvesting energy from the RF field and converting it to DC power sufficient to operate low-power sensor devices. Harry Ostaffe, Powercast director of marketing, said the company has so far deployed the technology in custom projects for military and industrial clients, with typical transmission distances “in the 10s of feet” using a three-watt transmitter.”
Power was transmitted to booths for Esensors and Infinite Power Solutions and converted back to DC with the P2100 Powerharvester. The Esensors wireless sensor was located about 35 feet from the Powercast transmitter. It was connected to a Powercast Yagi antenna module and was activated about every 90 seconds. The IPS energy cell was connected to a Powercast sleeve dipole antenna module and was pulse charged at about 25 feet. Longer charge distances were possible for both devices, but they were mounted for display purposes.
All of the demonstration modules are battery-free and are powered by RF energy that is converted to DC by Powercast’s P2100 Powerharvester module and stored in a supercapacitor. 
