Distributed solar generation (DSG), such as residential photo-voltaic (PV) solar panels, offers many benefits to consumers and can improve the sustainability and resilience of the electric power infrastructure. As such, many local and national authorities implemented policy incentives, such as rebates and loans with reduced interests, to promote the adoption of DSG. However, the increasing penetration of DSG is creating new obstacles for system operators due to the uncertainty in forecasting electrical power demand. There is a need to investigate how incentives affect DSG adoption. To achieve that goal, a complex system-of-systems (SoS) model is developed using agent-based modeling (ABM). The model can simulate the complex relationships between utilities and generating companies in wholesale power markets where consumers can make an economic decision to install DSG systems. The model is tested using a case study based on a modified IEEE 6-bus system. The findings highlight the need to carefully consider the rippling effect of incentives on the grid to ensure sustainable DSG diffusion as demonstrated using ABM.