**SOLAR AND WIND ENERGY**
# Solar Radiation Simulation Model

## Introduction

This **Solar Radiation Simulator** is a program in *JavaScript* for generating numerical data with the same properties as real solar radiation data in the tropics. It is based on the Solar Radiation Simulation Model for Quick Basic given on this web site.

To use the program enter the input values for the data you want in the form below, and click the button at the bottom of the form. The data file then appears in a separate window.

## Information Input

The items of input required are as follows:

**Latitude (deg):**
- The latitude given must be within the interval +25 deg (north of the equator) to -25 deg (south of the equator) because the model is correct only for the tropics. Initially the latitude "15" (for Central Thailand) appears in this text box, but you should fill in the correct latitude of your location.
**Mean daily solar irradiation on a horizontal surface each month (MJ/m**^{2}):
- Initially typical values for Central Thailand appear in the monthly text boxes, but you should fill in the correct values for your location.
**Orientation of tilted surface:**.
- The
*Azimuth (deg W)* is the angle between south (= zero degrees) and the direction in which the tilted surface is facing, measured towards the west. For example, west is 90 degrees, north is 180 degrees, and east is -90 degrees. The *Tilt angle (deg)* is the angle between the surface and the horizontal plane, which is the same as the angle between the normal to the surface and the zenith.

### Days of the Year

You can do the calculation for the whole year (365 days), or for selected days at regular intervals. Day #1 is 1 January, day #2 is 2 January, ..., day #365 is 31 December.

The numbers which appear initially in the form compute data from day #17 to day #365 with daily step 30; in other words, one day in the middle of each month: 17 Jan, 16 Feb, 18 Mar, 17 Apr, 17 May, 16 Jun, 16 Jul, 15 Aug, 14 Sep, 14 Oct, 13 Nov, 13 Dec.

Enter the first and last day, and the number of days in each interval step, to get data for the days you want.

## Solar Radiation Simulator

Copyright © 1999 by R. H. B. Exell

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By R. H. B. Exell, 1999. King Mongkut's University of Technology Thonburi.
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