Thermoelectric harvesters for Wireless Sensor Network

Nextreme Thermal Solutions Inc., a maker of thermoelectric modules has teamed up with Arkansas Power Electronics International Inc. to develop TEG harvesting system for wireless sensor network. In particular the WSN is designed to monitor the health of bearings in turbine engines.

Arpa-e funds $1.7M to develop Economically Printed Flexible Nanostructured Stacked Thermoelectric Junctions

The University of Illinois received funding through ARPA-E’s 37 Projects Selected From Funding Opportunity Announcement #1 to develop an economic and highly scalable approach to fabricate flexible thermoelectric junctions based on silicon nanotubes and optimize the energy conversion efficiency. The end of phase deliverable is a 1 square inch flexible thermoelectric module with effective ZT>1.2. Publish Post

NY Times list new thermoelectric company among the 10 to watch out of ARPA-E

Early-stage, high-risk, US government-supported and potentially game changing are the common features of these 10 companies. Phononic Devices is an ARPA-E awardee commercializing advanced materials nano-engineered to recapture waste heat and convert it into electric power, or conversely, to provide highly efficient refrigeration and cooling. Phononic Devices is one of only 37 companies selected by ARPA-E in their inaugural solicitation for funding to pursue "transformational" energy breakthroughs and is based on research done atOklahoma University. More detail can be found arpa-e website.

Flat-panel solar thermoelectric generators raise the roof

In a paper published on May 1 in Nature materials, Gang Chen's group at MIT describes a new radical concept to turn the sun's heat into electricity

While solar thermal electricity is not a new idea, typical existing systems rely on arrays of movable mirrors that track the sun and focus heat on a small area. The new approach uses flat stationary panels. The system achieved a already quite impressive peak efficiency of 4.6% under AM1.5G (1 kWm-2) condition.

The performance is enabled by the use of nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative flat design.

The device can be integrated into solar hot water systems and could be a relatively unexpensive addition.

Gains in Thermoelectric Performance for Bulk Semiconductor Material

"Researchers from Boston College, MIT, Clemson University and the University of Virginia have used nanotechnology to achieve a 60-90 percent increase in the thermoelectric figure of merit of p-type half-Heusler, a common bulk semiconductor compound. "

This is an example of one approach to improve thermoelectric materials by decreasing the thermal conductivity, while keeping the electrical conductivity relatively unchanged. Usually, the thermopower is also relatively constant, but in this instance the Seebeck coefficient increased. This suggest that grain boundaries may be trapping electrons, leading to increased holes in the sample and energy filtering effect. This may also be due to the involuntary introduction of dopants!

The measurement were done using standard commercial equipments and the uncertainties (without justification) were around 11% for ZT.

An other case for measurement of these quantities at the nanoscale and with reduced uncertainties!

Not that the grain size of the hot-pressed sample is around 200 nm compare to 5-10 nm for the precursors. "Preserving the size of the precursors remains an issue"

The paper can be found here: http://pubs.acs.org/doi/pdfplus/10.1021/nl104138t