The increasing demand for electricity in urban areas is often constrained by land limitations, necessitating innovative alternative solutions. One of the developing technologies is the floating Solar Power Plant (PLTS) which utilizes the water surface as a place to install solar panels. This research aims to design a small-scale floating PLTS at the IT-PLN artificial lake, focusing on the stability of the mechanical structure, the design of the electrical system, and the estimation of potential power and electrical energy that can be generated. The research methods include field surveys, literature studies, manual calculations, and simulations using HOMER Pro and PVsyst software. The mechanical structure is designed using HDPE drums as floats and a galvanized steel frame as support. The electrical system is built in an off-grid configuration with the main components being solar panels, batteries, an inverter, and a solar charge controller. The results of the manual calculations show that the output power from the data obtained in the Homer software is approximately 140 kW for an effective array area of 777.8 m2 with daily energy of 472.5 kWh. Meanwhile, the manual calculations obtained from the PVsyst software are approximately 49.3 kW for an effective array area of 274 m2 with daily energy of 166.3 kWh. The simulations provide the same results as the manual calculations. In the HOMER Pro software simulation, the estimated daily production is 472.5 kWh, while the PVsyst software simulation yields 166.3 kWh/day with a performance ratio of 39.19% and a solar fraction of 72.56%. Overall, this study proves that a floating solar power plant system is feasible for meeting light load requirements and has the potential to be developed as an environmentally friendly and efficient renewable energy solution for utilizing water space.