Solar radiation data are used to predict the performance of many different systemsfrom heating loads on buildings to electricity produced by concentrating collectors. It's not feasible to measure the solar resource for all these potential uses; rather, we must use models to calculate the incident solar radiation.
We are now developing tools, based on models, to facilitate the use of solar radiation data and present results in a useful format. Comments, suggestions, and questions about our software are always appreciated and will help us provide a better product.
If you'd like us to notify you when we develop or upgrade software tools, let us know.
Currently available tools
||The sun path chart program plots the path of the sun across the sky. These charts are used in site evaluation forms to identify trees, buildings, or other obstructions that would block direct access of solar radiation collecter to the sun. To create a sun path chart, you need to know the latitude and longitude of the site within about one degree or, for US locations, the local zip code. For more information, see our page about sun path charts.|
data plotting program graphically
depicts selected data, allowing you to see at a glance how irradiance
values, solar cell performance, or meteorological readings varied on
particular days at specified monitoring stations. In addition to this
general program interface, we've included links to it from all of our
Web pages devoted to currently active monitoring stations (such as this:
Eugene). These links cause the program to
display charts of the most recent data we have from our active stations.|
To download a zip file containing an Excel macro used to plot data from 5, 10, and 15 minute data click here for the plot macro. To run the program load the macro in Excel and click on the 'spade' button. The program will ask for the name of the file to be plotted. The file has to be in the UO SRML format.
sun dial program shows how the shadow
of a vertical rod, or 'gnomon' moves across a horizontal surface at
specific times at various locations on the earth. This application is
useful for anticipating the shading effects of objects near a PV array,
and, of course, it can be used to design an actual sun dial.||The
position calculator was developed to more accurately obtain astromonical parameters
such as solar declination, solar zenith
angle, equation of time, and hour angle
used in calculating the position of the sun. It's based on the work of Joe Michalsky
and the algorithm is used by SolPos, whose
is available on NREL's Web site.|
This program generates all the information needed to determine the position of the sun, based on date, time, and location. Also calculated are sunrise and sun set times, the instantaneous extraterrestrial radiation and the daily extraterrestrial radiation. These values are used when modeling solar radiation.
performance calculator, PVWatt, is located on NREL's Web
site. It calculates typical performance of solar electric arrays for more than
200 locations in the National Solar Radiation Database, given the
system peak output and orientation. Since actual performance will vary
from year to year, we created a modified version of PVWatt that works with data
from the UO SRML database. One goal is to make this Excel add-in available
as shareware on this Website.|
For more information
about instruments used to collect solar radiation data, and about our monitoring
stations, is found in the solar data section
of this site.
of solar resource assessment and solar radiation modeling will be incorporated
in our section devoted to educational
information on solar radiation modeling is available in our Solar Radiation
Data book and other publications on our Web site.
© 2010, UO Solar Radiation Monitoring Laboratory.
Last revised: June 7, 2010.
Home page URL: solardat.uoregon.edu