Objective Method for Selecting Outdoor Reporting Conditions for Photovoltaic Performance (open access)

Objective Method for Selecting Outdoor Reporting Conditions for Photovoltaic Performance

Outdoor performance of photovoltaic modules and systems depends on prevailing conditions at the time of measurement. Outdoor test conditions must be relevant to device performance and readily attainable. Flat-plate, nonconcentrator PV device performance is reported with respect to fixed conditions referred to as Standard Reporting Conditions (SRC) of 1 kW/m{sup 2} plane of array total irradiance, 25 C device temperature, and a reference spectral distribution at air mass 1.5 under certain atmospheric conditions. We report a method of analyzing historical meteorological and irradiance data to determine the range of outdoor environmental parameters and solar irradiance components that affect solar collector performance when the SRC 1 kW/m{sup 2} total irradiance value occurs outdoors. We used data from the 30 year U.S. National Solar Radiation Data Base (NSRDB) , restricting irradiance conditions to within +/- 25 W/m{sup 2} of 1 kW/m{sup 2} on a solar tracking flat-plate collector. The distributions of environmental parameter values under these conditions are non-Gaussian and site dependent. Therefore the median, as opposed to the mean, of the observed distributions is chosen to represent appropriate outdoor reporting conditions. We found the average medians for the direct beam component (834 W/m{sup 2}), ambient temperature (24.4 C), total column water …
Date: February 25, 1999
Creator: Myers, D. R.; Kurtz, S. (National Renewable Energy Laboratory); Whitaker, C.; Townsend, T. (Endecon Engineering: San Ramon, California) & Maish, A. (Sandia National Laboratories: Albuquerque, New Mexico)
System: The UNT Digital Library
The Daughter of Dawn: An Original Silent Film with an Oklahoma Indian Cast (open access)

The Daughter of Dawn: An Original Silent Film with an Oklahoma Indian Cast

Article explores the story and creation process of The Daughter of Dawn, one of the earliest silent motion pictures filmed in Oklahoma. Despite being produced by whites, its cast was entirely comprised of Oklahoma Indians.
Date: Autumn 1999
Creator: Kelley, Leo
System: The Gateway to Oklahoma History