Module Technology: Current Practice and Issues

PV modules must provide mechanical support for the cells, protect the world from the voltages inside, protect the cells, diodes and interconnects from the weather outside, couple as much light as possible into the PV cells and minimize the temperature increase of the cells. The package must continue to serve these functions for at least 25 years as that is the typical module warranty period today. Furthermore the package must do all this for as low a cost as possible since the key to large scale PV growth is a reduction in cost while retaining excellent module reliability and durability. This paper will review current module construction practices for both crystalline silicon and thin film PV with emphasis on explaining why the present designs and materials have been selected. Possible long term issues with today's designs and materials will be discussed. Several proposed solutions to these issues will be presented, highlighting the research efforts that will be necessary in order to verify that they can cost effectively solve the identified issues.
Date: October 5, 2010
Creator: Wohlgemuth, J.
Object Type: Presentation
System: The UNT Digital Library
Fighting Fire with Fire: Superlattice Cooling of Silicon Hotspots to Reduce Global Cooling Requirements (open access)

Fighting Fire with Fire: Superlattice Cooling of Silicon Hotspots to Reduce Global Cooling Requirements

The running costs of data centers are dominated by the need to dissipate heat generated by thousands of server machines. Higher temperatures are undesirable as they lead to premature silicon wear-out; in fact, mean time to failure has been shown to decrease exponentially with temperature (Black's law). Although other server components also generate heat, microprocessors still dominate in most server configurations and are also the most vulnerable to wearout as the feature sizes shrink. Even as processor complexity and technology scaling have increased the average energy density inside a processor to maximally tolerable levels, modern microprocessors make extensive use of hardware structures such as the load-store queue and other CAM-based units, and the peak temperatures on chip can be much worse than even the average temperature of the chip. In recent studies, it has been shown that hot-spots inside a processor can generate {approx} 800W/cm{sup 2} heat flux whereas the average heat flux is only 10-50W/cm{sup 2}, and due to this disparity in heat generation, the temperature in hot spots may be up to 30 C more than average chip temperature. The key problem processor hot-spots create is that in order to prevent some critical hardware structures from wearing out …
Date: October 5, 2010
Creator: Biswas, S; Tiwari, M; Sherwood, T; Theogarajan, L & Chong, F T
Object Type: Article
System: The UNT Digital Library
SALTSTONE 2QCY10 TCLP RESULTS (open access)

SALTSTONE 2QCY10 TCLP RESULTS

The Saltstone Production Facility (SPF) receives waste from Tank 50H for treatment. In the second quarter of the 2010 calendar year (2QCY10), Tank 50H accepted transfers of approximately 19 kgal from the Effluent Treatment Project (ETP), approximately 5 kgal from Tank 710 - the H-Canyon General Purpose Evaporator, approximately 42 kgal from the HCanyon Super Kukla campaign, and approximately 73 kgal from the Modular Caustic Side Solvent Extraction Unit (MCU) Decontaminated Salt Solution Hold Tank (DSS-HT). The Saltstone Grout Sampling plan provides the South Carolina Department of Health and Environmental Control (SCDHEC) with the chemical and physical characterization strategy for the salt solution which is to be disposed of in the Z-Area Solid Waste Landfill (ISWLF). During operation, samples were collected from Tank 50H and grout samples prepared to determine the non-hazardous nature of the grout to meet the requirements of the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24(b) and R.61-79.268.48(a). Savannah River National Laboratory (SRNL) was asked to prepare saltstone from samples of Tank 50H obtained April 4, 2010 during 2QCY10 to determine the non-hazardous nature of the grout. The samples were cured and shipped to Babcock & Wilcox Technical Services Group-Radioisotope and Analytical Chemistry Laboratory (B&W TSG-RACL) …
Date: October 5, 2010
Creator: Reigel, M.
Object Type: Report
System: The UNT Digital Library
Advanced Gasification Mercury/Trace Metal Control with Monolith Traps (open access)

Advanced Gasification Mercury/Trace Metal Control with Monolith Traps

Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m{sup 3} (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m{sup 3} (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic …
Date: October 5, 2010
Creator: Musich, Mark; Swanson, Michael; Dunham, Grant & Stanislowski, Joshua
Object Type: Report
System: The UNT Digital Library
Environmental Transport of Plutonium: Biogeochemical Processes at Femtomolar Concentrations and Nanometer Scales (open access)

Environmental Transport of Plutonium: Biogeochemical Processes at Femtomolar Concentrations and Nanometer Scales

None
Date: October 5, 2010
Creator: Kersting, A. B.
Object Type: Report
System: The UNT Digital Library