The aim of this article is to identify important factors that determine the strategy of the energy sector. It has been assumed that the determinants of this strategy are goals related to the energy security of a European Union member state and the reduction of environmental pollution and anthropogenic pressures. Therefore, this article uses the method of the strategic analysis of critical success factors (CSFs), applied to the energy sector. As the name implies, in this method, factors that determine energy strategies, relating to the economic, technological, political, social and ecological spheres, were identified. Poland served as a case study. Research was carried out by experts in the energy sector and people working with this sector in order to determine the significance of the most important CSFs related to the energy security strategy. This approach is based on an evolutionary approach to creating a security strategy. The proposed analysis is a new proposal for a sectorial analysis based on the application of benchmarking, taking into account, in particular, the current conditions for the development of the energy sector. Our findings indicate that: European Union countries have different energy strategies, resulting from an evolutionary approach. The member states of the European Union create individual solutions in the field of energy strategies, which are conditioned by many factors, the most important of which are the geographic and physical location of a country on the European continent, economic and social contexts, and environmental as well as political conditions. According to Polish experts, the key success factors in building an energy strategy stem mainly from the economic and political areas, followed by the technological area, while the environmental and social areas are the least important. The authors hope that the article will serve to popularize the use of CSFs in scientific research, which can then translate into improved government policies for the energy sector.