Advantaged by the unique environment and policies, solar panels have been widely adopted on the rooftops of houses in Australia. Studies have been focused on identifying the important socio-economic factors. However, variables relating to personnel may also affect people’s choices on solar panel adoption. Therefore, this study categorizes the 2633 Australian postal areas into four groups through K-means cluster analysis based on their solar adoption characteristics and identifies the significant impacting personnel-related factors in each group. The cluster map shows that regions with more advanced solar uptake levels are located closer to the capital cities of the Australian states. Moreover, regions with lower solar uptake levels have more significant variables, whereas areas with higher solar uptake levels exhibit the opposite trend. The study shall encourage the research community to explore more about the impact of personnel-related factors on residential solar uptake and inspire government departments and retailers to have more targeted strategies for promoting the use of solar energy.