Nowadays, one of the biggest challenges faced by EU countries is the pursuit of zero-emission economies. Certainly, it is crucial to determine the role of fossil fuels in the energy transformation. In light of the European Green Deal, EU countries should cease the consumption of hydrocarbons, i.e. coal, crude oil and natural gas, by 2050. Nevertheless, there are significant differences regarding the possibility of decarbonizing the energy sectors of the different EU Member States. For many years, Romania has been successively implementing an energy transformation, the main goal of which is the significant reduction of fossil fuels in the energy mix. Just a few years ago, one of the most important energy resources was coal, which is to be eliminated within the next decade. However, a much greater challenge is the reduction and subsequent abandonment of natural gas and crude oil. The key task facing Romania is to ensure energy security, which is why decarbonization will be strongly coupled with the country’s economic and political capabilities. The exclusion of fossil fuels in power engineering means that there is a need to develop alternative generation capacities, in particular in nuclear, wind and solar energy. This article presents the current condition of the energy sector in Romania, with a particular emphasis on the role of fossil fuels in its transformation. An analysis of documents and field research shows that there will be a dynamic decarbonization in the coming years, which will result in a significant reduction in the consumption of fossil fuels. The priority of Romania’s energy policy is to achieve a zero-emission economy, but ensuring stability and security in the energy sector will be of key importance in this process.

Humanity is being forced to alter how we use energy sources, to move away from fossil fuels and focus instead on renewable, especially solar energy. This transformation may prove to be the long sought-after “holy grail” of energy.

The article assesses the production capacity of the Polish Power System, taking into account the military operations in Ukraine and the related resource crisis. An analysis was made of how the war in Ukraine will affect the validity of Poland’s energy policy adopted a year ago. The sensitivity of the Polish Energy System to the import of energy resources from Russia was assessed as well as the possibilities of filling the gap caused by the lack of these raw materials were described and measures were proposed. It shows how electricity prices in the EU countries developed in the last year and what the energy mix of these countries looked like. Alternative scenarios for the transformation of the domestic system were discussed, including the coal – renewable energy – nuclear energy scenario, with the minimization of gas as a fuel of the transition period.