Carbon dioxide emissions and municipal solid waste are globally increasing, affecting the thin balance on Earth. Oxy-fuel combustion thermal power plants effectively reduce carbon dioxide emissions in the energy sector. However, carbon capture processes have a low over-all efficiency, which is a common disadvantage of this strategy. This thesis investigates the modelling using Aspen Plus of the Vantaan Energia waste-to-energy thermal power plant, taken as a reference case, to its retrofitting into a municipal solid waste oxy-fuel combustion thermal power plant with alkaline electrolysis cells. The simulation results report that the proposed design is not electrically self-sustainable, which requires an additional supply of 365.5 MWel.