The role of solar power has emerged as a predominant alternative to fossil fuel-based energy generation. Rajasthan has a vast potential for solar energy, and the state's climatic conditions make it ideal for capturing solar rays' sufficiency. These factors tend to adopt solar-based power plants as a perfect choice for the electricity supply of selfsustainable buildings. The solar-based captive power plant also helps overcome small residential societies' enormous electricity bill burden. So, many small to moderate residential societies & hostels are looking towards solar power-based generation systems over conventional electricity supply. Due to the variability of solar power available over the globe, different electricity charges and other atmospheric conditions require a proper analysis to prove the benefits of solar power-plant. This paper includes a systematic cost benefits analysis of an installed solar power plant of 50KW situated in West Jaipur, India. An educational hostel building has a total electricity bill of Rs. 7,69,05,179 electricity bills annually for the hostel block. A 50KW solar power plant cost around Rs. 20 Lakhs has installed to overcome this huge electricity bill burden for onsite generation and utilization. The cost-benefits analysis has shown saving around Rs 4 Lakhs per year and the total energy payback period is five years. The end-life cost benefits analysis also estimates the total financial benefits of around Rs. 82 Lakhs over 20 years. This financial benefit refers to the cost savings per solar plant in terms of clean energy and limited conventional energy reservoir savings.