The objective of this study was to investigate the amount of landfill gas obtained from the domestic solid waste stored regularly at the Sivas city solid waste landfill site and its usability for electricity generation. In this research, the actual data acquired from field studies were utilized for the calculation of the parameters. The total landfill gas, methane, and carbon dioxide emission amounts generated at the urban solid waste landfill site in Sivas city were determined by employing the LandGEM model. In the study, electricity generation via methane harnessing at the landfill site located in Sivas city, Turkey, was examined. The results obtained by examining the current situation of electricity generation from landfill gas power plant located in Sivas province were compared with the electricity generation capacities calculated according to the LandGEM estimation model version 3.02. The L0 value calculated for the Sivas landfill was 116.7 m3/Mg. The maximum quantities of total gas and methane emissions from the Sivas sanitary landfill were 7.976E+06 m3/year and 4.068E+06 m3/year, respectively. The outcomes of the LandGEM model as a mathematical model showed that the total gas and methane production rates in the first five years of landfilling were considerable. The constituents of the solid waste stream affected the gas emission rate at highest. The highest amount of energy to be generated was calculated to be 2947 kWh in 2030. The operational life of the Sivas Landfill Gas Power Plant will nearly end in an economic sense after 2060. It was observed that the actual data obtained from the power plant and the estimated data calculated using the LandGEM model were close to each other and the model made accurate predictions. It is possible to use the method and results of the current study to design and execute of methane gas collection systems and control the emission of greenhouse gases for landfills.