The high demand for electrical energy now results in an increasing need for Indonesia's electricity consumption annually. By designing solar power plants in Indonesia, it can be one solution to overcome the problem of increasing electricity consumption in Indonesia at this time. To find out the needs of the user can use the data collection method by interviewing directly to the manager of the Muhammadiyah Boarding School (MBS) in the electricity section or by manually calculating the amount of electricity load. For the method carried out at the Muhammadiyah Boarding School location, it used the method of interviewing directly with the MBS administrator in the electricity department. Based on the acquisition of data and calculations, it will do generating capacity planning, component selection, technical design, and economic analysis. The results of the calculation and analysis of the PLTS system design are made to supply electrical energy to lights and computers on SBM. From the results of the calculation of the total need for electric power of 193 kWh, in one day can be supplied using PLTS with a capacity of 55kWp. The design of this system uses a configuration of 172 solar panels with a capacity of 320 Wp, 120 12 volt batteries with a capacity of 105 Ah and a total cost of PLTS investment of Rp. 2928,487,629, - and maintenance and operational costs of Rp. 222,292,400 per year.