Trends in Renewable Energy OPEN ACCESS ISSN: 2376-2144 Peer-Reviewed Article futureenergysp.com/index.php/tre *Corresponding authors: henrilynnmfongang@gmail.com (Agbor M.E.); sam31628@gmail.com (Nwokolo S.C.) 78 Tr Ren Energy, 2023, Vol.9, No.1, 78-106. doi: 10.17737/tre.2023.9.1.00150 Effects of Angstrom-Prescott and Hargreaves-Samani Coefficients on Climate Forcing and Solar PV Technology Selection in West Africa Mfongang Erim Agbor 1 , Sunday O. Udo 1 , Igwe O. Ewona 1,2 , Samuel Chukwujindu Nwokolo* 1 , Julie C. Ogbulezie 1 , Solomon Okechukwu Amadi 3 , Utibe Akpan Billy 1 1: Department of Physics, Faculty of Physical Sciences, University of Calabar, Nigeria 2: Department of Physics, Faculty of Physical Sciences, Cross River University of Science and technology, Nigeria 3: Department of Physics, Faculty of Physical Sciences, Alex Ekwueme Federal University, Ndufu-Alike, Nigeria Received December 10, 2022; Accepted January 13, 2023; Published January 15, 2023 We evaluated and compared the performance of simulated Angström- Prescott (AP) and Hargreaves-Samani (HS) models on monthly and annual timescales using generalized datasets covering the entire West African region. The fitted AP model yielded more efficient parameters of a = 0.366 and b = 0.459, whereas the HS model produced a 0.216 coefficient based on an annual timescale, which is more suitable in the region compared to coefficients recommended by the Food and Agriculture Organization (FAO) (a = 0.25 and b = 0.5) and HS (0.17), respectively. Employing the FAO and HS recommended coefficients will introduce a relative percentage error (RPE) of 18.388% and 27.19% compared to the RPEs of 0.0014% and 0.1036% obtained in this study, respectively. When considering time and resource availability in the absence of ground-measured datasets, the coefficients obtained in this study can be used for predicting global solar radiation within the region. According to the AP and HS coefficients, the polycrystalline module (p- Si) is more reliable than the monocrystalline module (m-Si) because the p-Si module has a higher tendency to withstand the high temperatures projected to affect the region due to its higher intrinsic properties based on the AP and HS coefficients assessment in the region. Keywords: Ångström-Prescott coefficient; Hargreaves-Samani coefficient; Global solar radiation; Solar PV technologies; Climate forcing Introduction It is undeniable that the growth of solar PV installed capacity in the past years has outpaced the most optimistic projections, as indicated by global cumulative installed capacity at the end of 2013 being only 9.2 MW and worldwide cumulative capacity at year-end 2014 being 15.6 GW [1]. The exponential trend of PV installation growth started in 2008, and the total capacity has doubled every year, with the longest period of increase (since 2009) in 2014, when global installed capacity reached 15.6 GW and year- end solar power share was estimated at 5% of global electricity generation in just 6 years