# SolarCalc - Design of Alternative Energy Systems Solar...

This preview shows pages 1–2. Sign up to view the full content.

1 ME 417 Design of Alternative Energy Systems Solar Energy Calculations Solar Radiation Extraterrestrial radiation is give by ± ² ³ ´ µ · ¸ ¹ º » + = 365 n 360 cos 33 . 0 1 G G sc ext where n is the day of the year and GSC is solar constant, 1367 W/m 2 . The calculation of the solar radiation that will fall on a surface, G i , is given by G i = G B + G D + G R where G B : beam (direct) solar radiation that is intercepted by the surface G D : diffuse solar radiation that is intercepted by the surface G R : reflected beam solar radiation that is intercepted by the surface These terms depend on Day of the year (due to tilt of earth) Location, latitude and longitude Time of day (where the sun is in the sky) Inclination of the surface Local atmospheric conditions (cloud cover) and though the equations to calculate the solar radiation terms are well understood, they are quite involved and it is suggested that a web based calculator be employed. As a rough estimate the incident solar radiation to a surface varies between 200 to 400 W/m 2 . Focus or Concentrating Collectors The heat transfer rate delivered to the focal point of a concentrating solar collector is given by i col conc H G A Q η = where h conc : focusing efficiency of the collector A col : area of the collector G i : solar radiation incident to the collector

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 07/25/2008 for the course ME 417 taught by Professor Somerton during the Spring '07 term at Michigan State University.

### Page1 / 4

SolarCalc - Design of Alternative Energy Systems Solar...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online