The Impact of Air Mass on the Performance of a Monocrystalline Silicon Solar Module in Kakamega

5 6 7 8 . 9 ABSTRACT 10 11 This paper investigates the outdoor performance of a 20 W monocrystalline silicon solar module in relation to air mass (AM) in Kakamega. Direct measurement of air mass and module output parameters from experimental set up was done in Kakamega at a location 0.2827 0 N and 34.7519 E. Open circuit voltage and short circuit current was found to decrease with increasing air mass. Experimental results showed a decrease in ISC and VOC with increasing AM. The maximum output power produced by the module reduced with an increase in AM. Maximum power was therefore seen to be produced at noon in this region. The highest value of VOC obtained was 20.04 V at noon while ISC was 1.19 at noon. VOC increased from 19.47 to 20.04 then decreased to 19.49 V while ISC increased from 0.36 to 1.19 then decreased to 0.48A. It was observed that both the FF and η of a monocrystalline