This study analyses the interplay between internal factors and energy consumption behaviour among Lithuanian residents. The study employed secondary quantitative data analysis of two data sets—(1) data from the International Social Science Program (ISSP) “Environment IV” surveys collected in Lithuania and (2) data from a block of questions that was included in a common questionnaire during the KLIM-KOM project together with the ISSP “Environment IV” survey. Cluster analysis was performed to explore the gap between how Lithuanian residents view energy saving for environmental reasons and their actual energy consumption behaviour. It revealed that Lithuanian population can be divided into three groups—“Conscious Savers”, characterized by positive environmental energy saving attitudes and expressed energy saving behaviour; “Average Consumers”, characterized by average environmental attitudes and average energy saving behaviour; and “Dissonant Consumers”, characterized by positive environmental attitudes and average energy saving behaviour. Linear regression analysis was performed to analyse relationships between internal factors and energy saving behaviour across different clusters. It showed that the relationships between post-materialist values, environmental attitudes, subjective norms, perceived behavioural control, intentions, and energy consumption operate differently in these segments. The results provide valuable insights on what kind of behaviour change interventions could be effective for different parts of population.