@Article{pakinsight, AUTHOR = {}, TITLE = {Impact of the Optimal Tilt Angle on the Solar Photovoltaic Array Size and Cost for a 100 kWh Solar Power System in Imo State}, JOURNAL = {International Journal of Sustainable Energy and Environmental Research}, VOLUME = {8}, YEAR = {2019}, NUMBER = {1}, PAGES = {29-35}, URL = {http://www.pakinsight.com/archive/13/03-2019/1}, ISSN = {2306-6253}, ABSTRACT = {In this paper the impact of adjusting the optimal tilt angle of solar photovoltaic (PV) modules on monthly bases was studied and compared to that of the annually-fixed optimal tilt angle. PVSyst software was used to determine the optimal tilt angle for each month for a given case study site in Imo state in Nigeria. Mathematical models for computing the required PV array power to meet the daily energy demand of 100 kWh were presented. Addition parameters considered in the study were the PV array number of modules as well as PV array area and cost. For the case study 100 kWh daily energy demand, the selected PV module had a peak power rating of 100W, with a unit cost of N 18,000 and with dimensions that gave an area of 0.65945m^2. The results showed that there is about 4 % (annual average) reduction in the required PV array power when the monthly adjustment of the optimal tilt angle is used. December had the highest percentage reduction in the required PV array power. The reduction in the PV array power resulted in the corresponding reduction in the number of PV modules needed to provide the required power, as well as a reduction in PV array area and cost. }, DOI = { 10.18488/journal.13.2019.81.29.35} }