Displaying items by tag: technology
Technical Society of Knoxville Centennial Celebration
Jun 14 6:30 p.m. EST
The Turning Point: Things were never the same after 1921, when technology was changing the city in several surprising ways
Jack Neely, Executive Director of the Knoxville History Project
Technical Society of Knoxville (TSK)
Charity Banquet at Crowne Plaza for the Charles Edward Ferris Engineering Endowments at University of Tennessee, Knoxville - the public is invited - RSVP by June 8
Ferris was the first Dean of UTK’s College of Engineering.
More details on the event, sponsorships, and reservations
The Technical Society of Knoxville was founded in 1921. It has met over 4,000 times to discuss the application of technology from early Knoxville’s coal smoke and traffic problems to present Knoxville’s transportation air pollution and the impact of electric car technologies.
Frauenhofer tandem photovoltaic solar cell achieves record efficiency
The rainbow colors show the diffraction of sunlight by a mirror with a nanostructured grating, which was applied to the back of the silicon subcell. The sun’s spectrum is thus captured even better in the silicon bottom cell. © Fraunhofer ISE / Photo: Michael SchachtnerFraunhofer Institute for Solar Energy Systems: Tandem Photovoltaics Enables New Heights in Solar Cell Efficiencies – 35.9 % for III-V//Silicon Solar Cell
The photovoltaic (PV) solar panels most commonly used for commercial applications today have an efficiency in the range of 16 to 22 percent. On the lower side of this range, one finds less-expensive panels, mostly made with poly-crystalline solar cells, while monocrystalline cells dominate the upper side.
The highest-efficiency panel presently on the market is SunPower’s A-Series residential panel, with a claimed 22.8 percent efficiency in converting photons to electrons under standard conditions. That's up just slightly by 0.73 percent from five years ago. Although many other manufacturers have caught up to offer panels rated at more than 21 percent, development progress of silicon-based monocrystalline PV toward the theoretical limit of around 30 percent has slowed to a crawl.
Over the same period, newer technologies for multijunction PV cells with thin subcell layers of gallium-arsenide and similar semiconductors, grown on top of silicon or perovskite crystalline materials, has been progressing rapidly and may be capable of exceeding 50 percent efficiency in the future. Lab results still require years of research and manufacturing development before panels come to market. Initially their high price will limit them to market niches where low-weight and small-surface per Watt will justify the cost, such as for aerospace applications or covering electric vehicle surfaces. The following links provide a good overview of such technologies and discuss their longer-term outlook.