On Possibility of Converting Electricity Generation System Based on Fossil Fuels to Fully Renewable—Polish Case

The energy sector in all countries around the world is undergoing a transformation, with the main trend being the increasing share of renewable sources. Some countries, such as those in the European Union, have set themselves the goal of completely phasing out fossil fuels by 2050. Currently, the energy systems of European countries are far from this goal, and fossil fuels play a key role in balancing energy systems. This article presents a one-year simulation of a hypothetical Polish energy system based solely on renewable sources and utilizing biomethane, synthetic ammonia, and solid biomass as sources to ensure energy supply in the event of unfavorable weather conditions, which means a lack of wind and solar radiation. Six variants of these systems were analyzed, demonstrating the feasibility of such a system using only biogas as a stabilizing fuel. The required generating capacities of wind turbines, photovoltaic panels, and installations for converting biomethane, ammonia, and solid biomass into electricity were determined. Calculations were based on historical data recorded in 2024 in the Polish energy system. It was found that by increasing currently installed PV and wind turbines by a factor of 4.8 and installing 24 GW of ICE engines fueled with biomethane and an additional 10 GW of ORC modules, current electricity demand would be covered 100% by renewable energy sources. The same goal can be achieved without ORC modules by increasing the installed power of PV and wind turbines by a factor of 6.8. The novelty of this research is the application of the fully renewable concept of electricity generation systems to Polish reality using real-life data.