IDTechEx is in San Jose CA this week, and has attended a conference covering aspects of energy harvesting. Here are some of the highlights of company developments.
Micropelt the German thermoelectric harvesting company has developed MEMS based energy harvesting using thermal energy. The device has a heat sink on one side and is attached to a source of temperature. The temperature gradient can be used to generate electricity, and it can be a hot source going to a cold drain or vice versa. Different materials are used in the energy harvester depending on the temperature of the source. Micropelt require a temperature difference of at least ten degrees for the device to be useful. Micropelt is a VC funded company, based in Germany and comprises of 20 people. It has a range of thermal energy harvesting device examples, including a wireless sensor used for cooking. It has also developed a "ring" which fits on to mechanical engine bearings, using the heat from the bearing to power the sensor and transmit data every second. 500 million bearings are shipped each year and due to the mechanical stresses they can fail quickly. The power generated from the thermal harvester powers a 2.45GHz radio and monitors the working status of the bearing. In these examples, no battery is employed. The harvester itself is fabricated on silicon and a heat sink added. In Q2 2010 new production will open in Germany in a 10,000 square foot clean room with capacity to make 10 million devices a year. By 2011 cost could fall below $5 per harvester depending on the type and size. Micropelt expects this to replace high temperature batteries which are expensive in some applications.
Advanced Linear Devices is developing circuitry to boost the voltage generated from energy harvesters.
Powercast, a company working on RF transmission, reception and conversion has partnered with CAP-XX, a supplier of supercapacitors to enable batteryless wireless sensors. A 3W transmitter powers the 900MHz sensors in its range, charging the supercapacitor, and when transmission is needed the supercapacitor has enough energy to power the transmission burst.
A panel of speakers discussed the killer applications of energy harvesters. They cited watches and calculators. They felt that it is likely that wireless switches will be become a killer application in the future but with several hundred thousand out there, others would argue that they are a success already. These use the motion of pressing the switch to transmit a wireless signal to turn the light on or off. No batteries are employed. Retrofitting is significantly cheaper and building infrastructure more versatile - switches can be place anywhere. EnOcean, the company that designed these solutions, has 70 licensed members that integrate this solution. Battery versions have not been viable because of the limited lifetime of the battery. Here, energy harvesters have genuinely been an enabling technology. In addition, IDTechEx believe that there have been many killer applications i.e. fast growth and profitable applications for suppliers. These include satellites, road furniture, bicycle dynamos, garden lights, wind up torches/radios/lanterns, piezo gas lighters and military thermoelectrics.
Top Image San Jose CA. Source: Yellowpages
For more attend: Energy Harvesting and Storage Europe 2009
