A mathematical model has been developed to determine and optimize the therm
al and economical performance of large scale photovoltaic-electrolyzer syst
ems, either with fixed or sun tracking panels using hourly solar radiation
data. It has been found that the overall thermal efficiency of photovoltaic
-electro lyzer systems may be as high as 10.85% with sun tracking panels an
d 10.33% with fixed panels. The levelized solar hydrogen cost using either
fixed or sun tracking panels is well correlated with the total annual solar
radiation on a horizontal surface. Climatic conditions, altitude and latit
ude are not significant parameters affecting this correlation. The results
show that there is a practical minimum cost of hydrogen, which is 44.5 $/GJ
hydrogen when the PV system cost is 1 $/Wp and the capital charge rate is
15%. (C) 2001 Elsevier Science Ltd. All rights reserved.