Tools and Data

The Soltrex, Solar School House and Heliotronics Sunviewer all provide online graphing tools. The chosen power or irradiance data can be subset by time periods from hourly up to annual. The graphing tools are described in Parts 2 and 3.

Sunviewer from Heliotronics Choose from sites listed.

No cost, but user registration is required at Soltrex.

Help with interpreting the graph results:
From Heliotronics tool Sunviewer: Teacher Lessons and Tips
There are pdf files there that give some information on units of energy versus power and what the shape of a graph of solar power might mean. One such file is available for classroom use with proper citation to Heliotronics, Inc. Heliotronics Sunviewer Tutorial (Acrobat (PDF) 222kB Dec29 09)

A spreadsheet application may be used to analyze the data. Microsoft Excel is used in this chapter and is available as a stand-alone program or as part of Microsoft Office.

Microsoft Corporation
http://www.microsoft.com/en-us/default.aspx
Home Page for Excel

Students and educators may be able to purchase this software at a reduced cost.

Soltrex has 314 systems in 13 states as of December 2009

Heliotronics has 180 monitored sites in the US and Canada, but publicly available data is limited to 3 sites currently.

Solar School House has 128 monitored sites, primarily at schools.

The time range of the data varies from installation to installation and from Soltrex to Sunviewer to the Solar Schoolhouse. The dates of the installation of the panels and the monitoring equipment is provided at each location and varies from 10 years to a year and a half in some cases.