The concept of the energy trilemma provides a framework for supporting energy policy decisions based on three main dimensions, namely energy security, environmental sustainability, and energy equity. Contrary to models that focus on providing policy guidelines solely based on normative grounds, energy trilemma adopts a descriptive perspective that emphasizes the need to monitor and assess the observed results of energies policies and of all externalities that affect the status of a country and the challenges that it faces regarding energy planning. Building on the grounds of the energy trilemma concept, the objective of this study is to introduce a comprehensive framework and an evaluation process for operationalizing the assessment of the counties' performance from the energy trilemma point of view. To this end, first we describe the context of each of the main energy trilemma dimensions and suggest relevant indicators for each of them. We view energy security focusing on energy dependence and resilience, energy sustainability is considered in the context of energy use, energy efficiency, and environmental impacts, whereas energy equity is analyzed from the perspective of income availability and energy poverty. Moreover, we enhance the trilemma concept with a fourth dimension to account for the contextual environment of the countries, which is described in terms of their economic development, policy regulations, and innovations in energy and environmental technologies. This framework is operationalized through the consideration of 20 indicators using data from the World Bank and the OECD. The selected indicators provide a "bottom line" view for the context of each dimension regarding the current status of the countries, their existing strengths and weaknesses, as well as the challenges that they face, incorporating information for both the outcomes of policy decisions as well as external (uncontrollable) factors. The aggregation of the indicators provides composite indicators for each one of the four dimensions describe above, as well as an overall assessment. The construction of these composite evaluations is performed using a multicriteria approach, which is based on principles from efficiency measurement.