This article researches and models rooftop solar power for application at state management agencies in Khanh Hoa province. The research is based on state regulations, surveying the current situation at the headquarters of government agencies, and subsequently proposing a suitable rooftop solar power model. Simultaneously, rooftop solar models were implemented at the headquarters of government agencies in Khanh Hoa province with successful outcomes. The results indicated the effectiveness of reducing electricity consumption from the grid through rooftop solar technology applied to government administrative offices. Specifically, the solar power system achieved a 53.31% reduction in electricity consumption from the grid, meeting 100% of the office’s electricity demand for the year.