SolRC 1.3 FREE Worksheet calculates monthly average daily total insolation on a tilted toward south oriented surface on northern hemisphere or toward north oriented surface on southern hemisphere. It is a tool for students, teachers and others interested in solar energy (solar radiation) engineering. It could be also helpful for Engineers for quick estimation of solar radiation on tilted surfaces (toward south oriented facades, PV modules, solar collectors etc...).

 What can you calculate with SolRC:

With different input data (latitude, solar insolation on horizontal surfaces etc.) the student (designer) may compare results for different latitudes, tilt angles, insolation values etc. SolRC does not calculate solar insolation on partially shadowed surfaces. In case that you must calculate solar insolation on shadowed surfaces, please use tools that are mentioned in shading section.

 Neccessary input data:

Input data:

Solar constant (W/m²) - for solar constant Internet resources, please see Worksheet page 4
Monthly average daily solar insolation on horizontal surface (Wh/m²)
Ground reflectance ( - )
Surface tilt angle (deg) ( 0 deg <= tilt angle <= 90 deg )
Location latitude (deg, min, sec) (northern hemisphere only)

You may change the red fields (input data), but you may not change yellow or green fields (results). According to the instructions in suggested literature you can design your own worksheet where other diffuse radiation fraction calculation can be used. In suggested literature you will find other calculation examples for diffuse radiation fraction (please see suggested literature for more details). For the Solar constant values please follow hyperlinks or see the literature.

You may change the following (red) fields:

PAGE 1: Location description, Solar constant value, Location latitude, day of the month, mean daily insolation on horizontal surface for each month. You may also change surface tilt angle (cell F29) - instead 10 deg you may type tilt angle as you wish and calculation for the chosen angle will be made). Please note that the chosen tilt angle should be >= 0 deg and <= 90 deg. When chosen tilt angle is out of range (0 deg <= tilt angle <= 90 deg) in F27 cell you can see the text "FALSE INPUT DATA". In this case the output calculation is not correct (StarOffice Worksheet) or you can not see that calculated values at all (MS Excell Worksheet). By other input data there is no control what data you type in, so if you mistype any other input value (day of the month or the insolation on horizontal surface values for example), the output calculation will be wrong. In this case on page 3, above the results you will see the text "INCORRECT RESULTS".

PAGE 2: Ground reflectance values for each month.

 Help and explanation pages:

For explanation and help you may see pages 3 and 4, where some formulas are presented and some literature for further explanation and study is suggested. With the help of literature page you may design your own Worksheet for inclined, toward E or W oriented surfaces for example. In new Worksheet you may also change the diffuse radiation fraction calculation and use diffuse radiation fraction (Klein - Erbs or Collares - Perreira for example), more suitable for your climate condition or season.

 Disclaimer:

You may non-commercial copy and distribute this FREE Worksheet without limitations. You may not commercialy sell, rent or distribute this software. You may not modify the Worksheet without authors permission. The Worksheet is being delivered to you as is and author makes no warranty as to its use or performance. Author does not and cannot warrant the performance or results you may obtain by using the worksheet. In no event will author be liable to you for any damages, claims or costs whatsoever or any consequential, indirect, incidental damages, or any lost profits or lost savings, even if author has been advised of the possibility of such loss, damages, claims or costs or for any claim by any third party.