In addition, the performance ratio of Portici, Italy demonstrated contradicting with Rome, Italy under similar climatic conditions, even relatively close in the final yield is presented. In similar system at Ratchaburi, Thailand has a PR of 59% with a YF of 3.58, which appears to be conflicting and should be looked into. The lowest based on YF is 1.31 in the UK. Based on the reports published, it shows that the a-Si PV module performed best in the Malaysian climate.