Effects of ambient temperatures, tilt angles, and orientations on hybrid photovoltaic/diesel systems under equatorial climates

Temperature and solar radiation are two main parameters directly affecting PV (photovoltaic) arrays' output. Particularly, solar radiation is dependent upon PV arrays' tilt angles and orientations while PV arrays' temperatures are related to ambient temperatures. Nevertheless, the effects of ambient temperatures, tilt angles, and orientations on PV arrays' output for places with equatorial climatic conditions (and abundant sunshine) are scarcely reported. In this paper, the effects of ambient temperatures, tilt angles, and orientations on the total electricity produced by PV arrays and the total NPCs (net present costs) of hybrid PV/diesel systems were studied using HOMER (Hybrid Optimization of Multiple Energy Resources). Three places with different latitudes off the equator (0 degrees 00' N, 5 degrees 58' N, and 11 degrees 14' N) were analyzed and the results showed that increasing ambient temperatures (10-50 degrees C) and tilt angles (0-90 degrees) resulted in reductions in PV electricity as much as 18% and 55%, respectively. NPC-wise, however, the variations became less pronounced - the NPC differences caused by changes in ambient temperatures and tilt angles became similar to 6% and similar to 25%, respectively, under 0% annual real interest rate. As the annual real interest rate increased to 3% and 5%, the NPC differences reduced further. Meanwhile, at 0-30 degrees tilt angles, PV arrays facing different orientations showed differences in NPCs of less than 5%, albeit that the reductions in PV electricity were much higher. Significantly, the implementation of hybrid PV/diesel systems is feasible at places with equatorial climates.