In this research, a new trigeneration system with the prime mover of solid oxide fuel cells and solar energy was simulated to supply the required energy of a sample building in Shahrood, Iran. For this purpose, at first, the required loads of the building have been calculated. Then, the trigeneration system was used to provide the required heating, cooling, and electrical loads for the building. The analysis was performed for each component of the system from energy aspects. Then the obtained equations were solved using EES software. The results showed that the total amount of electrical power produced by the system in spring and summer is about 1184.5 kW and in autumn and winter is 1121.7 kW. The total electrical energy produced by the system during the year is about 9921112 kWh. Also, 1301.2 MWh of thermal energy was collected by 50 solar panels throughout the year. The electrical efficiency of the fuel cell is 46.77% and the whole system is 53.97%. Also, the thermal efficiency of the whole system is equal to 86.9%. The carbon dioxide emission coefficient is 358.2, which is very low and desirable compared to fossil fuel systems. Due to the intensity of solar radiation in the city of Shahrood, the designed system can provide heat and cold loads for the building well and the efficiency of the trigeneration system is much higher than similar systems and the amount of pollution is much lower.