SIMULATION OF THE PERFORMANCE AND OPTIMAL SIZE OF PHOTOVOLTAIC SYSTEM USING HELIOPHYSICAL VARIABLES

Abstract

A method of simulating the performance and optimal size of photovoltaic (PV) systems based on the observed time series of some heliophysical variables was developed and explored in this research. The data used were the sunshine duration and solar radiation intensity for years 1990 to 2004 for eleven Nigerian stations obtained from the archives of the Nigeria Meteorological Agency NIMET. Appropriate programs were developed using MatlabR code to model the performance of a photovoltaic system and the optimal values of photovoltaic area. Input parameters which were estimated from the obtained heliophysical variables and used in the simulation were clearness index and total radiation on an inclined surface. The output parameters include utilizability, monthly average fraction of the load covered by the photovoltaic system with battery storage, monthly-average fraction of the load covered by the photovoltaic system without battery storage, monthly-average of uncovered load fraction of the photovoltaic system, area of the panel, optimal area of the panel, optimal total cost of the panel and the increase in the solar load fraction due to storage. Solar load fraction with storage ranges between 27.2% and 28.2% conversion efficiency of solar cell. Maximum incident solar radiation onto the photovoltaic array is obtainable in dry season which lead to better performance of photovoltaic electrical output and lower values of utilizability either when the excess solar load fractions are being stored or not. The average cost of the optimized plant, capable of supplying 15 kW, is #809,800. A comparison of the optimized cost with PHCN current charge indicated that after one year and six months, the user of the plant wi!!jJecome a free user of electricity! The optimized photovoltaic plant is short term cost -e-f-.f~ective and much cheaper than the non - optimized plant.