It is worth mentioning that despite of the decrease of coal generation in the energy mix, the fuel remains crucial for energy sector stabilizing the energy system and securing the energy supply in Poland as well as has a positive impact on the energy security of the European Union. The development of renewable energy will be possible with conventional energy compensating the unstable operation of renewable energy sources as climate conditions in Poland do not allow for the sustainable usage of renewable energy sources and thus, their effective utilization. The modernization of 200 MW energy generating units as well as the possible construction of 2–3 similar units will enable the stabilization of the amount of electricity in the transmission grid. The modern and modernized 200 MW energy generating units are able to maintain grid operation if needed and it will be easier to phase them out gradually as prosumer energy and energy storage technologies are being developed. Due to the held and planned general and additional generation capacity auctions for years following 2020, we are assured that despite the substantial increase of distributed generation sources in Poland’s energy mix, the electricity supply to end-users will be stable and safe.