Thesis (M.Eng.) - Asian Institute of Technology, 1993

A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering.

The solar radiation availability on a horizontal surface at Auroville, India, has been analyzed to facilitate the design and performance prediction of solar systems. Mean values of hourly and daily global solar radiation are found for all months of the year. Maximum and minimum values of daily radiation are observed in March and November, respectively. These months also have the maximum and minimum values of average daily clearness index. The frequency distributions of hourly global radiation for January were similar in all hours of the day except for the first and last hours of daylight. Frequency distributions of daily total and daily clearness index are presented for three typical months. Generalized K distribution curves given by Liu and Jordan are found not to be valid for Auroville. Cumulative Frequency Curves (CFC) and Utilizability Curves (UC) are generated from hourly and daily values of global radiation for 12 months. Models are developed to represent these CFC and UC curves. Radiation values generated from Exell's program gave nearly the same utilizability curves except for the month of November. This supports the validity of Exell's program in Auroville's context except in November when the weather is more variable. A method to predict long term performance of directly coupled solar PV pumping systems is presented. The application of utilizability values to predict solar load fraction of PV systems is investigated.